[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (571)

Search Parameters:
Keywords = CLSM

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
18 pages, 4984 KiB  
Article
Development of Extrudable Hydrogels Based on Carboxymethyl Cellulose–Gelatin Complex Coacervates
by Hamid Gharanjig, Hossein Najaf Zadeh, Campbell Stevens, Pram Abhayawardhana, Tim Huber and Ali Reza Nazmi
Gels 2025, 11(1), 51; https://doi.org/10.3390/gels11010051 - 8 Jan 2025
Viewed by 369
Abstract
This study investigates the 3D extrusion printing of a carboxymethyl cellulose (CMC)–gelatin complex coacervate system. Various CMC–gelatin coacervate hydrogels were prepared and analyzed to achieve this goal. The impact of the CMC–gelatin ratio, pH, and total biopolymer concentration on coacervation formation and rheological [...] Read more.
This study investigates the 3D extrusion printing of a carboxymethyl cellulose (CMC)–gelatin complex coacervate system. Various CMC–gelatin coacervate hydrogels were prepared and analyzed to achieve this goal. The impact of the CMC–gelatin ratio, pH, and total biopolymer concentration on coacervation formation and rheological properties was evaluated to characterize the printability of the samples. Turbidity results indicated that the molecular interactions between gelatin and CMC biopolymers are significantly pH-dependent, occurring within the range of pH 3.7 to pH 5.6 for the tested compositions. Confocal Laser Scanning Microscopy (CLSM) confirmed the presence of coacervates as spherical particles within the optimal coacervation range. Scanning electron microscopy micrographs supported the CLSM findings, revealing greater porosity within this optimal pH range. Rheological characterization demonstrated that all CMC–gelatin hydrogels exhibited pseudoplastic behavior, with an inverse correlation between increased coacervation and decreased shear viscosity. Additionally, the coacervates displayed lower tackiness compared to gelatin hydrogels, with the maximum tackiness normal force for various CMC–gelatin ratios ranging from 1 to 15 N, notably lower than the 29 N observed for gelatin hydrogels. Mixtures with CMC–gelatin ratios of 1:15 and 1:20 exhibited the best shear recovery behavior, maintaining higher strength after shear load. The maximum strength of the CMC–gelatin coacervate system was found at a biopolymer concentration of 6%. However, lower biopolymer content allowed for consistent extrusion. Importantly, all tested samples were successfully extruded at 22 ± 2 °C, with the 1:15 biopolymer ratio yielding the most consistent printed quality. Our research highlights the promise of the CMC–gelatin coacervate system for 3D printing applications, particularly in areas that demand precise material deposition and adjustable properties. Full article
(This article belongs to the Special Issue Cellulose-Based Gels: Synthesis, Properties, and Applications)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>(<b>a</b>) Turbidity values as a function of pH for CMC–gelatin ratios of 1:10, 1:15, 1:20, and 1:25. (<b>b</b>) Coacervation pH window for CMC–gelatin ratios of 1:10, 1:15, 1:20, and 1:25. pH<sub>Φ1</sub> and pH<sub>Φ2</sub> represent subsets of dramatic increase or decrease in turbidity; pH<sub>opt1</sub> and pH<sub>opt2</sub> indicate the optimum pH range for coacervation.</p>
Full article ">Figure 2
<p>CLSM images of the CMC–gelatin mixture with a total biopolymer concentration of 0.1% (<span class="html-italic">w</span>/<span class="html-italic">w</span>) prepared at various pHs (the pH was gradually decreased through dropwise addition of acetic acid 50%, 10%, or 2% <span class="html-italic">w</span>/<span class="html-italic">v</span>) with gelatin stained using Rhodamine B (scale bar indicates 10 µm).</p>
Full article ">Figure 3
<p>Micrograph of the CMC–gelatin cryogels prepared at a ratio of 1:20, a total biopolymer concentration of 4%, and different pHs: (<b>a</b>) pH 3.5 (outside of the coacervation range), (<b>b</b>) pH 5.0 (inside of the coacervation range).</p>
Full article ">Figure 4
<p>Steady-state viscosity (<b>a</b>) and storage modulus (<b>b</b>) for CMC–gelatin samples with a ratio of 1:20 and total biopolymer concentration of 4% at pH of 3.5 (♦), 4.5 (■), 5.0 (▲), and 6.5 (●).</p>
Full article ">Figure 5
<p>Rheological behavior of coacervate system samples at a concentration of 4% and CMC–gelatin ratio of 1:10 (▲), 1:15 (♦), 1:20 (●), and 1:25 (■) compared to gelatin at 4% concentration (Complex viscosity (<b>a</b>), Storage modulus (<b>b</b>), Controlled shear viscosity (<b>c</b>), and Tackiness (<b>d</b>)).</p>
Full article ">Figure 6
<p>Steady-state-controlled shear rheometry for coacervate system samples prepared with CMC–gelatin ratios of 1:10 (▲), 1:15 (♦), 1:20 (●), and 1:25 (■) at a total biopolymer concentration of 4% and pH 4.5, showcasing behavior under increasing (solid line) and decreasing (dashed line) shear rates.</p>
Full article ">Figure 7
<p>Rheological characteristics of coacervate system samples prepared at pH 4.5, CMC–gelatin ratio of 1:20, and total biopolymer concentration of 4% (●), 5% (■), and 6% (▲) and 4% sole gelatin hydrogel (Controlled shear viscosity (<b>a</b>), Storage Modulus (<b>b</b>), and Tackiness (<b>c</b>)).</p>
Full article ">Figure 8
<p>Print failures: examples of discontinuities in printed samples of (<b>a</b>) 1:20 ratio and (<b>b</b>) 1:25 ratio.</p>
Full article ">Figure 9
<p>Printability of CMC–gelatin ratios 1:10. 1:15, 1:20, and 1:25, alongside images of their respective printed structures.</p>
Full article ">
27 pages, 27890 KiB  
Article
Optical Methods for Determining the Phagocytic Activity Profile of CD206-Positive Macrophages Extracted from Bronchoalveolar Lavage by Specific Mannosylated Polymeric Ligands
by Igor D. Zlotnikov, Alexander A. Ezhov, Natalia I. Kolganova, Dmitry Yurievich Ovsyannikov, Natalya G. Belogurova and Elena V. Kudryashova
Polymers 2025, 17(1), 65; https://doi.org/10.3390/polym17010065 - 30 Dec 2024
Viewed by 510
Abstract
Macrophage (Mph) polarization and functional activity play an important role in the development of inflammatory lung conditions. The previously widely used bimodal classification of Mph into M1 and M2 does not adequately reflect the full range of changes in polarization and functional diversity [...] Read more.
Macrophage (Mph) polarization and functional activity play an important role in the development of inflammatory lung conditions. The previously widely used bimodal classification of Mph into M1 and M2 does not adequately reflect the full range of changes in polarization and functional diversity observed in Mph in response to various stimuli and disease states. Here, we have developed a model for the direct assessment of Mph from bronchial alveolar lavage fluid (BALF) functional alterations, in terms of phagocytosis activity, depending on external stimuli, such as exposure to a range of bacteria (E. coli, B. subtilis and L. fermentum). We have employed polymeric mannosylated ligands (the “trapping ligand”) specifically targeting the CD206 receptor to selectively isolate activated Mph from the BALF of patients with pulmonary inflammatory conditions: primary ciliary dyskinesia (PCD), pneumonia and bronchial asthma. An “imaging ligand” allows for the subsequent visualization of the isolated cells using a sandwich technique. Five model strains of E. coli, MH-1, JM109, BL21, W3110 and ATCC25922, as well as B. subtilis and L. fermentum strains, each exhibiting distinct properties and expressing red fluorescent protein (RFP), were used as a phagocytosis substrate. Fluorometric, FTIR- and confocal laser scanning microscopy (CLSM) assessments of the phagocytic response of Mph to these bacterial cells were performed. Mph absorbed different strains of E. coli with different activities due to the difference in the surface villosity of bacterial cells (pili and fimbriae, as well as signal patterns). In the presence of other competitor cells (like those of Lactobacilli), the phagocytic activity of Mph is changed between two and five times and strongly dependent on the bacterial strain. The relative phagocytic activity indexes obtained for BALF-Mph in comparison with that obtained for model human CD206+ Mph in the M1 polarization state (derived from THP-1 monocyte cultures) were considered as a set of parameters to define the Mph polarization profile from the BALF of patients. Mannan as a marker determining the selectivity of the binding to the CD 206 mannose receptor of Mph significantly inhibited the phagocytosis of E. coli and B. subtilis in cases of pneumonia, suggesting an important role of CD206 overexpression in acute inflammation. Conversely, L. fermentum binding was enhanced in PCD, possibly reflecting altered macrophage responsiveness in chronic lung diseases. Our approach based on the profiling of Mph from patient BALF samples in terms of phagocytosis for a range of model bacterial strains is important for the subsequent detailed study of the factors determining dangerous conditions and resistance to existing therapeutic options. Full article
(This article belongs to the Section Polymer Applications)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>(<b>a</b>) Molecular absorption spectra of bacterial suspensions (4 × 10<sup>8</sup> CFU/mL) of <span class="html-italic">E. coli</span> MH-1, JM109, BL21, W3110 and ATCC25922 expressing red fluorescent protein (RFP). (<b>b</b>) Molecular absorption spectra of only RFP in the same bacterial suspensions. (<b>c</b>) Fluorescent spectra of the same bacterial suspensions (4 × 10<sup>8</sup> CFU/mL) of <span class="html-italic">E. coli</span> MH-1, JM109, BL21, W3110 and ATCC25922 at λ<sub>exci</sub> of 520 nm. (<b>d</b>) Molecular absorption and fluorescent spectra of <span class="html-italic">Lactobacilli</span> cells stained with methylene blue (MB) at λ<sub>exci</sub> of 630 nm and T = 37 °C.</p>
Full article ">Figure 2
<p>A schematic representation of the “sandwich” approach for the isolation and staining of CD206+ macrophages in biological fluids employing the use of high-affinity trimannoside ligands as trapping and imaging tools. The trapping ligand is triMan-PEG-PEG, and imaging ligand is HPCD-PEI-triMan-FITC (<a href="#polymers-17-00065-sch001" class="html-scheme">Scheme 1</a> and <a href="#polymers-17-00065-sch002" class="html-scheme">Scheme 2</a>).</p>
Full article ">Figure 3
<p>(<b>a</b>) AFM image of a “trap polymer” film (trimannoside-PEG) deposited onto a freshly cleaned mica surface. (<b>b</b>) An enlarged image. (<b>a</b>) A magnitude signal. (<b>c</b>) AFM image of macrophages from the BALF deposited onto freshly cleaned mica surface. (<b>d</b>) Increased AFM image; (<b>c</b>) magnitude signal.</p>
Full article ">Figure 4
<p>(<b>a</b>) CLSM images of CD206+ macrophages stained with HPCD-PEI-triMan-FITC imaging ligand. λ<sub>exci</sub> = 488 nm. λ<sub>emi</sub> = 505–600 nm. (<b>b</b>) Fluorescent spectra of HPCD-PEI-triMan-FITC imaging ligand (10 µg/mL) at λ<sub>exci</sub> of 480 nm. (<b>c</b>) A map of the spatial distribution of the integrated signal intensity in the FTIR spectra of the triMan-PEG “visualization ligand” associated with CD206+ macrophages revealing a pattern characterized by a peak ν(C–O–C) at 1100–1000 cm<sup>−1</sup>. The regions marked with red correspond to areas with a high concentration of the ligand, which in turn is associated with the expression of the CD206 receptor, while blue indicates the absence of receptors. (<b>d</b>) FTIR spectrum of “trapping ligand” triMan-PEG. PBS (pH 7.4, 0.01 M). T = 37 °C. (<b>e</b>) Histograms of CD206+ macrophage distribution by FITC fluorescence intensity when stained with HPCD-PEI-triMan-FITC imaging ligand (compared with medium-affinity mannose ligand and low-affinity galactose ligand) according to flow cytometry data.</p>
Full article ">Figure 5
<p>(<b>a</b>) Kinetic curves of <span class="html-italic">E. coli</span> phagocytosis by CD206+ macrophages from the BALF in the absence and presence of <span class="html-italic">Lactobacilli</span> competitor. Kinetic curves were recorded by changing the fluorescence of the red protein as a percentage of the initial one. (<b>b</b>) The correlation between the number of bacteria interacting with macrophages and MIC values for levofloxacin (LF). The dotted line shows the trend lines and confidence coefficients. The macrophage density was 10<sup>6</sup> cells per well plate. The bacterial density was 5 × 10<sup>7</sup> for all strains. LB medium/PBS (50:50 <span class="html-italic">v</span>:<span class="html-italic">v</span>, pH 7.4, 0.01 M). T = 37 °C.</p>
Full article ">Figure 6
<p>(<b>a</b>) Confocal laser scanning microscopy images of CD206+ macrophages derived from BALF after 4 h of incubation with <span class="html-italic">E. coli</span> MH-1 cells in the presence of <span class="html-italic">Lactobacilli</span> competitor cells. Macrophage nuclei were stained with DAPI (λ<sub>ex,max</sub> = 360 nm; λ<sub>emi</sub> = 400–500 nm); macrophages were stained with FITC anti-CD206 ligand (HPCD-PEI1.8-triMan-FITC)—green channel (λ<sub>ex,max</sub> = 488 nm; λ<sub>emi</sub> = 505–555 nm). <span class="html-italic">E. coli</span> cells were stained RFP—red channel (λ<sub>ex,max</sub> = 559 nm; λ<sub>emi</sub> = 575–625 nm). (<b>b</b>) Confocal laser scanning microscopy images of CD206+ macrophages derived from model human THP-1 monocytes after 4 h of incubation with <span class="html-italic">E. coli</span> MH-1 cells in the presence of <span class="html-italic">Lactobacilli</span> cells. Macrophages were stained with FITC anti-CD206 ligand (HPCD-PEI1.8-triMan-FITC)—green channel (λ<sub>ex,max</sub> = 488 nm; λ<sub>emi</sub> = 500–520 nm). <span class="html-italic">E. coli</span> cells were stained with eosin (covalent)—red channel (λ<sub>ex,max</sub> = 515 nm; λ<sub>emi</sub> = 530–600 nm).</p>
Full article ">Figure 7
<p>Confocal laser scanning microscopy images of CD206+ macrophages derived from BALF after 4 h of incubation with different <span class="html-italic">E. coli</span> cells. Macrophages were stained with FITC anti-CD206 ligand (HPCD-PEI1.8-triMan-FITC)—green channel (λ<sub>ex,max</sub> = 488 nm; λ<sub>emi</sub> = 505–555 nm). <span class="html-italic">E. coli</span> cells were stained RFP—red channel (λ<sub>ex,max</sub> = 559 nm; λ<sub>emi</sub> = 575–625 nm).</p>
Full article ">Figure 8
<p>Correlation analysis of the phagocytic activity of CD206+ macrophages in BALF against different bacterial cells, depending on the presence or absence of mannan, a competitive ligand for CD206 receptors.</p>
Full article ">Scheme 1
<p>A scheme of synthesis of the trimannoside-PEG (triMan–PEG) trapping ligand.</p>
Full article ">Scheme 2
<p>A scheme of synthesis of FITC-labeled HPCD-PEI-X “imaging ligand” for macrophage visualization.</p>
Full article ">
15 pages, 3181 KiB  
Article
Effect of EGCG–Methacrylate-Functionalized Resin Infiltrant on White Spot Lesions: An In Vitro Study
by Karin Landmayer, Bruna de Oliveira Iatarola, Talita Portela Pereira, Raquel Shimizu Mori, Alyssa Teixeira Obeid, Mariele Vertuan, Daniela Alvim Chrisostomo, Ana Carolina Magalhães, Lulwah Alreshaid, Paulo Henrique dos Santos, Anuradha Prakki and Luciana Fávaro Francisconi-dos-Rios
J. Funct. Biomater. 2025, 16(1), 6; https://doi.org/10.3390/jfb16010006 - 29 Dec 2024
Viewed by 524
Abstract
This study evaluated the color change (ΔE00) and penetration depth (PD) of white spot lesions (WSLs) infiltrated with the resin infiltrant (Icon®) functionalized with methacrylate epigallocatechin-3-gallate (EGCG). To introduce polymerizable double bonds, EGCG was reacted with methacryloyl chloride (EM). [...] Read more.
This study evaluated the color change (ΔE00) and penetration depth (PD) of white spot lesions (WSLs) infiltrated with the resin infiltrant (Icon®) functionalized with methacrylate epigallocatechin-3-gallate (EGCG). To introduce polymerizable double bonds, EGCG was reacted with methacryloyl chloride (EM). Subsequently, the Icon resin infiltrant (I) was loaded with neat EGCG (IE) or EGCG–methacrylate (IEM) at 2 wt% each. WSLs were created on bovine enamel blocks and treated with I, IE, or IEM. Sound and untreated enamel surfaces were used as controls (C). Infiltrant PD (%) was determined by Confocal Laser Scanning Microscopy (CLSM, n = 12) analysis. For color change (ΔE00) determination (n = 14), ΔL, Δa, and Δb, half of each sample was kept sound as a reference area. The color was determined with a spectrophotometer. Data were statistically evaluated (p = 0.05). Surface morphology was obtained as a qualitative response variable using 3D CLSM. PD (%) did not differ statistically for I, IE, and IEM (p = 0.780). Groups I and IEM showed similar performance on color change (ΔE00) compared to the control group, while IE exhibited intermediate results, with no significant difference observed between the untreated, I, and IEM groups (p < 0.001). IEM promoted the masking of the WSL color without interfering with the PD. Full article
(This article belongs to the Special Issue Biomaterials in Restorative Dentistry and Endodontics)
Show Figures

Figure 1

Figure 1
<p>Representative transverse microradiography (TMR) images of enamel white spot lesion from sample 1 (<b>A</b>), sample 2 (<b>B</b>), and sample 3 (<b>C</b>). All samples exhibited an outer surface layer corresponding to the pseudo-intact surface layer over the body of lesion typical of caries white spot lesions.</p>
Full article ">Figure 2
<p>Illustrative images obtained by CLSM according to experimental groups, as follows: (<b>A</b>) resin infiltrant (I-Icon); (<b>B</b>) EGCG-functionalized Icon (IE); (<b>C</b>) EGCG–methacrylate-functionalized Icon (IEM). Rhodamine B dye (reddish areas) indicates the infiltrated region, while sodium fluorescein (greenish areas) highlights the non-infiltrated porous areas.</p>
Full article ">Figure 3
<p>Data (25%/median/75%) of ΔE<sub>00</sub> values of the control group (C), untreated white spot lesion (L), groups treated with Icon (I), epigallocatechin-3-gallate (EGCG)-functionalized Icon (IE), or EGCG–methacrylate-functionalized Icon (IEM). Different letters indicate statistically significant differences.</p>
Full article ">Figure 4
<p>Data (25%/median/75%) of ΔL values of the control group (C), untreated white spot lesion (L), groups treated with Icon (I), EGCG-functionalized Icon (IE), or EGCG–methacrylate-functionalized Icon (IEM). Different letters indicate statistically significant differences.</p>
Full article ">Figure 5
<p>Data (25%/median/75%) of Δa values color coordinates (green–red axis) of the control group (C), untreated white spot lesion (L), groups treated with Icon (I), EGCG-functionalized Icon (IE), or EGCG–methacrylate-functionalized Icon (IEM). Different letters indicate statistically significant differences.</p>
Full article ">Figure 6
<p>Means and standard deviations of Δb values color coordinate (blue–yellow axis) of the control group (C), untreated white spot lesion (L), groups treated with Icon (I), EGCG-functionalized Icon (IE), or EGCG–methacrylate-functionalized Icon (IEM). Different letters indicate statistically significant differences.</p>
Full article ">Figure 7
<p>Surface morphology images obtained by CLSM according to experimental groups, as follows: (<b>A</b>) control (C), (<b>B</b>) untreated white spot lesion (L), (<b>C</b>) Icon resin infiltrant (I); (<b>D</b>) EGCG-functionalized Icon (IE); (<b>E</b>) EGCG-methacrylate-functionalized Icon (IEM).</p>
Full article ">
12 pages, 3618 KiB  
Article
Synergistic Effects and Mechanisms of Action of Rutin with Conventional Antibiotics Against Escherichia coli
by Lankun Yi, Yubin Bai, Xu Chen, Weiwei Wang, Chao Zhang, Zixuan Shang, Zhijin Zhang, Jiajing Li, Mingze Cao, Zhen Zhu and Jiyu Zhang
Int. J. Mol. Sci. 2024, 25(24), 13684; https://doi.org/10.3390/ijms252413684 - 21 Dec 2024
Viewed by 481
Abstract
Rutin is a widely known plant secondary metabolite that exhibits multiple physiological functions. The present study focused on screening for synergistic antibacterial combinations containing rutin, and further explored the mechanisms behind this synergy. In vitro antibacterial test results of rutin showed that the [...] Read more.
Rutin is a widely known plant secondary metabolite that exhibits multiple physiological functions. The present study focused on screening for synergistic antibacterial combinations containing rutin, and further explored the mechanisms behind this synergy. In vitro antibacterial test results of rutin showed that the ranges of minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) are 0.125–1 and 0.125–2 mg/mL, respectively. However, rutin and amikacin have a significant synergistic effect, with a fractional inhibitory concentration index (FICI) range of 0.1875–0.5. The time bactericidal curve proved that the combination of rutin and amikacin inhibited bacterial growth within 8 h. Scanning electron microscopy (SEM) revealed that a low-dose combination treatment could disrupt the cell membrane of Escherichia coli (E. coli). A comprehensive analysis using alkaline phosphatase (AKP), K+, and a protein leakage assay revealed that co-treatment destroyed the cell membrane of E. coli, resulting in the significant leakage of AKP, intracellular K+, and proteins. Moreover, confocal laser scanning microscopy (CLSM) and red–green cell ratio analysis indicated severe damage to the E. coli cell membrane following the co-treatment of rutin and amikacin. This study indicates the remarkable potential of strategically selecting antibacterial agents with maximum synergistic effect, which could significantly control antibiotic resistance. Full article
Show Figures

Figure 1

Figure 1
<p>Time–kill curves of rutin and amikacin combined against <span class="html-italic">Escherichia coli</span>. (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): <span class="html-italic">Escherichia coli</span> T31.</p>
Full article ">Figure 2
<p>Scanning Electron Microscopy observation of <span class="html-italic">Escherichia coli</span> morphology (10,000×). (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): Amikacin-treated <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>C</b>): Rutin-treated <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>D</b>): Rutin and Amikacin-treated <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>E</b>): <span class="html-italic">Escherichia coli</span> T31; (<b>F</b>): Amikacin-treated <span class="html-italic">Escherichia coli</span> T31; (<b>G</b>): Rutin-treated <span class="html-italic">Escherichia coli</span> T31; (<b>H</b>): Rutin and Amikacin-treated <span class="html-italic">Escherichia coli</span> T31. The red parts are the representative change of the pictures.</p>
Full article ">Figure 3
<p>Effect of rutin and amikacin alone or combined on <span class="html-italic">Escherichia coli</span> Alkaline Phosphatase leakage. (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): <span class="html-italic">Escherichia coli</span> T31. Each value is presented as the mean ± SD (<span class="html-italic">n</span> = 3). ns <span class="html-italic">p</span>-value &gt; 0.05, *** <span class="html-italic">p</span>-value &lt; 0.001, **** <span class="html-italic">p</span>-value &lt; 0.0001.</p>
Full article ">Figure 4
<p>Effect of rutin and amikacin alone or combined on <span class="html-italic">Escherichia coli</span> K<sup>+</sup> leakage. (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): <span class="html-italic">Escherichia coli</span> T31. Each value is presented as the mean ± SD (<span class="html-italic">n</span> = 3). ns <span class="html-italic">p</span>-value &gt; 0.05, *** <span class="html-italic">p</span>-value &lt; 0.001, **** <span class="html-italic">p</span>-value &lt; 0.0001.</p>
Full article ">Figure 5
<p>Effect of rutin and amikacin alone or combined on <span class="html-italic">Escherichia coli</span> protein leakage. (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): <span class="html-italic">Escherichia coli</span> T31. Each value is presented as the mean ± SD (<span class="html-italic">n</span> = 3). * <span class="html-italic">p</span>-value &lt; 0.05, *** <span class="html-italic">p</span>-value &lt; 0.001, **** <span class="html-italic">p</span>-value &lt; 0.0001.</p>
Full article ">Figure 6
<p>Confocal Laser Scanning Microscopy observes changes in <span class="html-italic">Escherichia coli</span> cell membrane integrity. (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): amikacin-treated <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>C</b>): rutin-treated <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>D</b>): rutin and amikacin-treated <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>E</b>): <span class="html-italic">Escherichia coli</span> T31; (<b>F</b>): amikacin-treated <span class="html-italic">Escherichia coli</span> T31; (<b>G</b>): rutin-treated <span class="html-italic">Escherichia coli</span> T31; and (<b>H</b>): rutin and amikacin-treated <span class="html-italic">Escherichia coli</span> T31. Scale Bar: 50 µm.</p>
Full article ">Figure 7
<p>Analysis of the red–green ratio of bacteria in Confocal Laser Scanning Microscopy results. (<b>A</b>): <span class="html-italic">Escherichia coli</span> ATCC 25922; (<b>B</b>): <span class="html-italic">Escherichia coli</span> T31. Each value is presented as the mean ± SD (<span class="html-italic">n</span> = 3). ns <span class="html-italic">p</span>-value &gt; 0.05, * <span class="html-italic">p</span>-value &lt; 0.05, **** <span class="html-italic">p</span>-value &lt; 0.0001.</p>
Full article ">Figure 8
<p>Diagram of the mechanism of action of rutin and amikacin combined against <span class="html-italic">Escherichia coli.</span> When rutin is combined with amikacin, it destroys the cell wall and cell membrane of <span class="html-italic">E. coli</span>, allowing a large amount of the drug to enter the bacteria. Amikacin inhibits ribosomes from synthesizing proteins. At the same time, AKP, intracellular K<sup>+</sup>, and proteins are leaked in large quantities, eventually causing the bacteria to lose their vitality.</p>
Full article ">
16 pages, 12963 KiB  
Article
Evaluating Bioflocculation Harvesting of Freshwater and Marine Microalgae Using Exopolysaccharides (EPSs) from Klebsiella sp.
by Yicheng Yuan, Jingxuan Lu and Quan Wang
Separations 2024, 11(12), 355; https://doi.org/10.3390/separations11120355 - 19 Dec 2024
Viewed by 544
Abstract
The rising global energy demand and environmental concerns associated with fossil fuels have intensified interest in sustainable biofuel sources, with microalgae emerging as a viable candidate due to its high biomass yield and efficient CO2 conversion. However, the economic feasibility of microalgal [...] Read more.
The rising global energy demand and environmental concerns associated with fossil fuels have intensified interest in sustainable biofuel sources, with microalgae emerging as a viable candidate due to its high biomass yield and efficient CO2 conversion. However, the economic feasibility of microalgal biofuels is currently challenged by costly harvesting processes. This study investigates the use of exopolysaccharides (EPSs) derived from Klebsiella sp. as an environmentally friendly bioflocculant for harvesting two microalgae species: Raphidocelis subcapitata and Dunaliella salina. Comparative flocculation experiments revealed that Klebsiella EPS promotes efficient aggregation in R. subcapitata, achieving over 90% flocculation efficiency, while performance with D. salina was impacted by high salinity, which reduced charge neutralization and bridging effects. Structural analyses using FTIR, 3D-EEM, CLSM, and XPS elucidated the EPS composition, underscoring the roles of polysaccharides and proteins in facilitating microalgal aggregation. The findings indicate that Klebsiella EPS offers a sustainable alternative to chemical flocculants, supporting eco-friendly biofuel production and potential applications in wastewater treatment. This approach provides insights into optimizing EPS-based flocculation for diverse environmental conditions, paving the way for more sustainable biomass recovery practices. Full article
(This article belongs to the Special Issue Separation Technology for Solid Waste Treatment and Recycling)
Show Figures

Figure 1

Figure 1
<p>Harvesting efficiency of (<b>a</b>) directly added <span class="html-italic">Klebsiella</span> sp. suspensions, (<b>b</b>) EPS extracted from <span class="html-italic">Klebsiella</span> sp. on two microalgae species.</p>
Full article ">Figure 2
<p>Floc structures of (<b>a</b>) RS15-K4, (<b>b</b>) RS15-K8, (<b>c</b>) 90EPS-RS, (<b>d</b>) DS15-K4, (<b>e</b>) DS15-K8, and (<b>f</b>) 90EPS-DS under 20× optical microscopy.</p>
Full article ">Figure 3
<p>SEM imaging of floc structures: (<b>a</b>) RS15-K4, (<b>b</b>) RS15-K8, (<b>c</b>) 90EPS-RS, (<b>d</b>) DS15-K4, (<b>e</b>) DS15-K8, and (<b>f</b>) 90EPS-DS.</p>
Full article ">Figure 4
<p>Particle size distributions of floc structures: (<b>a</b>) <span class="html-italic">R. subcapitata</span>, (<b>b</b>) <span class="html-italic">D. salina</span>, and (<b>c</b>) zeta-potential change after the addition of <span class="html-italic">Klebsiella</span> sp. broth.</p>
Full article ">Figure 5
<p>(<b>a</b>) FTIR spectra detailing the chemical composition of EPS. (<b>b1</b>–<b>b3</b>) The 3D-EEM spectra for S-EPS, LB-EPS, and TB-EPS. (<b>c1</b>–<b>c5</b>) CLSM images of <span class="html-italic">Klebsiella</span>: general cellular staining (<b>c1</b>), specific red staining for lipids (<b>c2</b>), blue staining for proteins (<b>c3</b>), green staining for polysaccharides (<b>c4</b>), and a composite overlay of all stains (<b>c5</b>). (<b>d</b>) Pie chart showing the composition ratios of S-EPS, LB-EPS, and TB-EPS in EPS.</p>
Full article ">Figure 6
<p>XPS spectra for total EPS and S-EPS: (<b>a1</b>,<b>b1</b>,<b>c1</b>) represent the C1s, O1s, and N1s spectra for total EPS, respectively, while (<b>a2</b>,<b>b2</b>,<b>c2</b>) show the high-resolution C1s, O1s, and N1s spectra for S-EPS.</p>
Full article ">
21 pages, 4320 KiB  
Article
Chlorogenic Acid: A Promising Strategy for Milk Preservation by Inhibiting Staphylococcus aureus Growth and Biofilm Formation
by Xiaoyan Yu, Yufang Li, Xue Yang, Jinze He, Wenhuan Tang, Yunmei Chai, Zuyan Duan, Wenjie Li, Dan Zhao, Xuefeng Wang, Aixiang Huang, Hong Li and Yanan Shi
Foods 2024, 13(24), 4104; https://doi.org/10.3390/foods13244104 - 18 Dec 2024
Viewed by 517
Abstract
Chlorogenic acid (CGA), a polyhydroxy phenolic acid, has been extensively studied for its antimicrobial properties. Staphylococcus aureus (S. aureus) threatens food safety by forming biofilms. This study aimed to investigate the mechanism of CGA against S. aureus and its biofilm. The [...] Read more.
Chlorogenic acid (CGA), a polyhydroxy phenolic acid, has been extensively studied for its antimicrobial properties. Staphylococcus aureus (S. aureus) threatens food safety by forming biofilms. This study aimed to investigate the mechanism of CGA against S. aureus and its biofilm. The anti-bacterial activity of CGA was assessed using crystal violet staining, TEM, SEM, a CLSM, and using metabolomics and molecular docking to elucidate the mechanism. The results indicated that the minimum inhibitory concentration of CGA against S. aureus was 2.5 mg/mL. CGA disrupts the integrity of bacterial cell membranes, leading to increased hydrophobicity, morphological changes, scattering, and reduced spreading. This disruption decreases biofilm adhesion and bacterial count. Metabolomics and molecular docking analyses revealed that CGA down-regulates key amino acids. It forms hydrogen bonds with penicillin-binding protein 4 (PBP4), Amidase, glutamate synthetase B, and glutamate synthetase A. By inhibiting amino acid metabolism, CGA prevents biofilm formation. CGA interacts with amino acids such as aspartic acid, glutamine, and glutamate through hydroxyl (-OH) and carbonyl (-C=O) groups. This interaction reduces cell viability and biofilm cohesion. The novel findings of this study, particularly the extension of the shelf life of pasteurized milk by inhibiting S. aureus growth, highlight the potential of CGA as a promising anti-biofilm strategy and preservative in the dairy industry. Full article
(This article belongs to the Section Food Microbiology)
Show Figures

Figure 1

Figure 1
<p>Antibacterial effect of CGA against <span class="html-italic">S. aureus</span> in the early stage of biofilm formation. (<b>A</b>) The MIC of CGA against <span class="html-italic">S. aureus</span> (** indicates a significant difference, <span class="html-italic">p</span> &lt; 0.05). (<b>B</b>) Effect of CGA on the growth of <span class="html-italic">S. aureus</span>. (<b>C</b>) Effect of CGA on the surface hydrophobicity of <span class="html-italic">S. aureus</span> cells (different lowercase letters on the column indicate that the difference is statistically significant, <span class="html-italic">p</span> &lt; 0.05). (<b>D</b>) SEM observation on the effect of CGA on the early biofilm of <span class="html-italic">S. aureus</span>. (<b>E</b>) TEM observation on the effect of CGA on the early biofilm of <span class="html-italic">S. aureus.</span> (<b>F</b>) Effect of CGA on the structure of early biofilm of <span class="html-italic">S. aureus</span>.</p>
Full article ">Figure 2
<p>Inhibitory activity of CGA on <span class="html-italic">S. aureus</span> biofilm. (<b>A</b>) Effect of CGA on the spreading of <span class="html-italic">S. aureus</span> cells in the early stage of biofilm formation. (<b>B</b>) The inhibitory activity of different concentrations of CGA on <span class="html-italic">S. aureus</span> biofilm formation. (<b>C</b>) The inhibition rate of different concentrations of CGA on <span class="html-italic">S. aureus</span> biofilm formation. (<b>D</b>) DAPI staining of <span class="html-italic">S. aureus</span> biofilms. (<b>E</b>) CLSM images of <span class="html-italic">S. aureus</span> biofilms. Different lowercase letters on the column indicate that the difference is statistically significant, <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 3
<p>(<b>A</b>) Three-dimensional score scatter plot of PCA model. (<b>B</b>) The OPLS-DA model score scatter diagram. (<b>C</b>) The point diagram of the permutation test results of the OPLS-DA model. (The abscissa represents the permutation retention of the permutation test and the ordinate represents the R<sup>2</sup>Y or Q<sup>2</sup> value. The green dot represents the R<sup>2</sup>Y value obtained by the permutation test, the blue square point represents the Q<sup>2</sup> value obtained by the permutation test, and the two dashed lines represent the regression lines of R<sup>2</sup>Y and Q<sup>2</sup>.) (<b>D</b>) The histogram of permutation test results of the OPLS-DA model. (<b>E</b>) Volcano plot of the 349 differential metabolites between the control and CGA-treated groups. (<b>F</b>) Heat map of the 46 differential metabolites between the control and CGA-treated groups.</p>
Full article ">Figure 4
<p>(<b>A</b>) Metabolic pathway enrichment analysis of the differential metabolites in the control and CGA-treated groups. (<b>B</b>) Molecular docking analysis of CGA and key enzymes involved in biofilm formation.</p>
Full article ">Figure 5
<p>(<b>A</b>) Single-molecule electrostatic potential energy distribution maps of CGA and ASP, GLN, and GLU. (<b>B</b>) The electrostatic potential energy distribution of CGA and ASP, GLN, and GLU. Blue represents the positive potential region, and red represents the negative potential region.</p>
Full article ">Figure 6
<p>Effect of CGA on <span class="html-italic">S. aureus</span> in pasteurized milk. (<b>A</b>) The inhibitory effect of CGA on <span class="html-italic">S. aureus</span> in pasteurized milk. (<b>B</b>) The appearance map of CGA treatment (the upper right corner indicates the dilution ratio, ns, <span class="html-italic">p</span> &gt; 0.05, ** <span class="html-italic">p</span> ≤ 0.01 and *** <span class="html-italic">p</span> ≤ 0.001, compared with the control group).</p>
Full article ">
24 pages, 11881 KiB  
Article
Stability and pH-Dependent Mechanism of Astaxanthin-Loaded Nanoemulsions Stabilized by Almond Protein Isolate
by Qingrui Yang, Wenhui Qi, Yutong Shao, Xu Zhang, Fengyang Wu and Zhisheng Zhang
Foods 2024, 13(24), 4067; https://doi.org/10.3390/foods13244067 - 17 Dec 2024
Viewed by 658
Abstract
Pickering emulsions (PEs) of natural plant proteins enriched in fat-soluble components are gaining consumer interest for healthier and sustainable products. The aim of this study is to prepare PEs for stabilizing almond protein isolated (API) particles loaded with astaxanthin using ultrasound technology. The [...] Read more.
Pickering emulsions (PEs) of natural plant proteins enriched in fat-soluble components are gaining consumer interest for healthier and sustainable products. The aim of this study is to prepare PEs for stabilizing almond protein isolated (API) particles loaded with astaxanthin using ultrasound technology. The loose structure of the API at pH levels of 3 and 12, with contact angles of 68.92° and 72.56°, respectively, facilitated its transfer from the aqueous to the oil phase. The adsorption of the API at the oil–water interface was 71.56% and 74.69% at pH levels of 3 and 12, respectively, which was significantly higher than that of the emulsions at other pH levels (5, 7, and 9). After 14 days of storage at 4 °C, PEs at pH levels of 3 and 12 did not undergo phase separation, with small and homogeneous droplets. CLSM revealed a monolayer arrangement of the API at the oil–water interface. These results indicate that PE is more stable at pH levels of 3 and 12 than at other pH levels (5, 7, and 9). In addition, the stabilized astaxanthin PE showed the largest astaxanthin encapsulation (91.43%) at a pH of 3. The emulsions had significantly lower a* values and higher L* values at a pH of 3 compared to a pH of 12, indicating better astaxanthin stability in the PEs. These results will help to expand the application of API-PE loaded with astaxanthin at different pH values. Full article
(This article belongs to the Section Food Physics and (Bio)Chemistry)
Show Figures

Figure 1

Figure 1
<p>(<b>A</b>) Appearance of APIs at pH levels of 3, 5, 7, 9, and 12, passing through a 200 mesh sieve; (<b>B</b>) SEM micrographs of the APIs at pH levels of 3, 5, 7, 9, and 12. The scale bars are 10.0 μm.</p>
Full article ">Figure 2
<p>SDS−PAGE (<b>A</b>), FTIR (<b>B</b>), and secondary structure content (<b>C</b>) of APIs at pH levels of 3, 5, 7, 9, and 12.</p>
Full article ">Figure 2 Cont.
<p>SDS−PAGE (<b>A</b>), FTIR (<b>B</b>), and secondary structure content (<b>C</b>) of APIs at pH levels of 3, 5, 7, 9, and 12.</p>
Full article ">Figure 3
<p>Contact angles (θ) of APIs at different pH values.</p>
Full article ">Figure 4
<p>OM (<b>A</b>) and CLSM images (<b>B</b>) of stabilized emulsions with an API concentration of 1.0 wt%. (<b>C</b>) The Cryo−SEM image of stabilized emulsions with an API concentration of 1.0 wt% at pH levels of 3 and 12. The volume fraction of the oil was controlled to 30%.</p>
Full article ">Figure 4 Cont.
<p>OM (<b>A</b>) and CLSM images (<b>B</b>) of stabilized emulsions with an API concentration of 1.0 wt%. (<b>C</b>) The Cryo−SEM image of stabilized emulsions with an API concentration of 1.0 wt% at pH levels of 3 and 12. The volume fraction of the oil was controlled to 30%.</p>
Full article ">Figure 5
<p>Droplet size (<b>A</b>), percentage size (<b>B</b>), and zeta potential (<b>C</b>) of API−stabilized PEs at different pH values (3–12) on day 1 and day 14. The results were expressed as mean ± standard deviation (n = 3). a–e: Different letters above standard deviation bar indicate significant differences among the means (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 5 Cont.
<p>Droplet size (<b>A</b>), percentage size (<b>B</b>), and zeta potential (<b>C</b>) of API−stabilized PEs at different pH values (3–12) on day 1 and day 14. The results were expressed as mean ± standard deviation (n = 3). a–e: Different letters above standard deviation bar indicate significant differences among the means (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 6
<p>Interfacial protein adsorption rate of API-PEs at different pH values. The concentration of APIs was 1% <span class="html-italic">w</span>/<span class="html-italic">v</span>, and the fraction of oil was 0.3. The results were expressed as mean ± standard deviation (n = 3). a–e: Different letters above standard deviation bar indicate significant differences among the means (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 7
<p>Rheological properties (<b>A</b>) viscosity, (<b>B</b>) frequency of API−PE at different pH values. The concentration of APIs was 1% <span class="html-italic">w</span>/<span class="html-italic">v</span>, and the fraction of oil was 0.3.</p>
Full article ">Figure 7 Cont.
<p>Rheological properties (<b>A</b>) viscosity, (<b>B</b>) frequency of API−PE at different pH values. The concentration of APIs was 1% <span class="html-italic">w</span>/<span class="html-italic">v</span>, and the fraction of oil was 0.3.</p>
Full article ">Figure 8
<p>(<b>A</b>) Typical visual images of the various emulsions stored for 14 days. (<b>B</b>) Creaming index of API-PEs during 14 days of storage at different pH values. The API concentration was 1.0% <span class="html-italic">w</span>/<span class="html-italic">v</span>, and the oil fraction was 0.30. The results were expressed as mean ± standard deviation (n = 3). a–d: Different letters above standard deviation bar indicate significant differences among the means (<span class="html-italic">p &lt;</span> 0.05).</p>
Full article ">Figure 9
<p>Appearance and schematic representation of AP-PEs loaded with astaxanthin at different pHs.</p>
Full article ">
12 pages, 4121 KiB  
Article
The Impact of Silver Nanoparticles on Dentinal Tubule Penetration of Endodontic Bioceramic Sealer
by Sundus Bukhary, Sarah Alkahtany, Amal Almohaimede, Nourah Alkhayatt, Shahad Alsulaiman and Salma Alohali
Appl. Sci. 2024, 14(24), 11639; https://doi.org/10.3390/app142411639 - 12 Dec 2024
Viewed by 765
Abstract
The impact of adding silver nanoparticles (AgNPs) to bioceramic (BC) sealer on their ability to penetrate dentinal tubules is still unknown. Thus, this confocal laser scanning microscopic (CLSM) study aimed to assess the extent of dentinal tubule penetration of BC sealer (TotalFill® [...] Read more.
The impact of adding silver nanoparticles (AgNPs) to bioceramic (BC) sealer on their ability to penetrate dentinal tubules is still unknown. Thus, this confocal laser scanning microscopic (CLSM) study aimed to assess the extent of dentinal tubule penetration of BC sealer (TotalFill® Hiflow BC Sealer™, FKG, Switzerland) with and without AgNPs using the single-cone (SC) technique and the continuous-wave condensation (CWC) technique. AgNPs alone as well as in a mixture with the BC sealer were characterized using scanning electron microscopy and transmission electron microscopy. Single-rooted extracted human teeth (N = 100) were selected and prepared, and then divided into four groups (n = 25). Group 1 (BC/SC): BC sealer obturated with the SC technique. Group 2 (BC+AgNPs/SC): BC sealer with AgNPs obturated with the SC technique. Group 3 (BC/CWC): BC Sealer obturated with the CWC technique. Group 4 (BC+AgNPs/CWC): BC Sealer with AgNPs obturated with the CWC technique. After 2 weeks, roots were horizontally sectioned to obtain 1 mm thick dentin slices that were evaluated with CLSM. Sealer dentinal tubule penetration area and the maximum depth of penetration were measured. Data were analyzed with one-way ANOVA and the Tukey multiple comparison tests (p ≤ 0.05). The characterization process demonstrated a spherical-shaped nanoparticles without obvious agglomeration. The results showed that Group 2 (BC+AgNPs/SC) significantly demonstrated the highest mean tubular penetration depth, while group 3 (BC/CWC) had the lowest mean depth. Group 2 (BC+AgNPs/SC) exhibited the significantly highest mean value for the total area of penetration. However, groups 1 (BC/SC) and 3 (BC/CWC) exhibited the lowest mean value of total penetration area, with no statistically significant difference. The integration of AgNPs with BC sealer markedly enhanced penetration into dentinal tubules. The SC technique demonstrated superior penetration relative to the CWC technique. Full article
Show Figures

Figure 1

Figure 1
<p>(<b>A</b>) Maximum penetration depth measurement; (<b>B</b>) total area of sealer penetration measurement. All images are shown at 5× magnification.</p>
Full article ">Figure 2
<p>(<b>A</b>) SEM image of AgNPs illustrating the spherical shape and size range (×200,000); (<b>B</b>) TEM image of AgNPs illustrates the spherical-shaped particles, as well as the absence of nanoparticles agglomeration (×300,000); (<b>C</b>) TEM image of AgNPs mixed with bioceramic sealer demonstrates the spherical shape of AgNPs precipitated within the structure of the sealer, with no obvious agglomeration (×150,000).</p>
Full article ">Figure 3
<p>The bar chart shows the mean ± standard deviations of the maximum depth of penetration (<b>A</b>) and total area of sealer penetration (<b>B</b>) of the experimental groups.</p>
Full article ">Figure 4
<p>Representative CLSM images showing the penetrability of the experimental sealers into dentinal tubules. (<b>A1</b>–<b>A4</b>) represent the BC+AgNPs/SC group, showing heavy and homogenous fluorescence, indicating great sealer penetration with long tags from the canal lumen toward the cementodentinal junction. (<b>B1</b>–<b>B4</b>) represent the BC+AgNPs/CWC group, showing sealer penetration through the dentinal tubules with long tags. (<b>C1</b>–<b>C4</b>) represent the BC/SC group, showing minimal sealer penetration into dentinal tubules with short tags. (<b>D1</b>–<b>D4</b>) represent the BC/CWC group, denoting hardly noticeable fluorescence, indicating minimal sealer penetration into dentinal tubules. All images are shown at 10× magnification. All bars represent 200 µm.</p>
Full article ">
14 pages, 4257 KiB  
Article
The Influence of CLSM Magnification on the Measured Roughness of Differently Prepared Dental Materials
by Martin Rosentritt, Anne Schmutzler, Sebastian Hahnel and Laura Kurzendorfer-Brose
Materials 2024, 17(23), 5954; https://doi.org/10.3390/ma17235954 - 5 Dec 2024
Viewed by 456
Abstract
This in vitro study investigated how varying magnifications (5×, 10×, 20×, and 50×) using a confocal laser scanning microscope (CLSM) influence the measured surface roughness parameters, Ra/Sa and Rz/Sz, of various materials with two surface treatments. [...] Read more.
This in vitro study investigated how varying magnifications (5×, 10×, 20×, and 50×) using a confocal laser scanning microscope (CLSM) influence the measured surface roughness parameters, Ra/Sa and Rz/Sz, of various materials with two surface treatments. Cylindrical specimens (d ≈ 8 mm, h ≈ 3 mm, n = 10) from titanium, zirconia, glass-ceramic, denture base material, and composite underwent diamond treatment (80 μm; wet) and polishing (#4000; wet; Tegramin-25, Struers, G). The surface roughness parameters (Ra/Sa, Rz/Sz) were measured with a CLSM (VK-100, Keyence, J) at 5×, 10×, 20×, and 50× magnifications. Line roughness (Ra/Rz) was measured along a 1000 μm distance in three parallel lines, while area roughness (Sa/Sz) was evaluated over a 2500 μm × 1900 μm area. The statistical analysis included ANOVA, the Bonferroni post hoc test, and Pearson correlation (SPSS 29, IBM, USA; α = 0.05). Ra/Sa and Rz/Sz showed significant differences (p ≤ 0.001, ANOVA) across magnifications, with values decreasing as magnification increased, highest at 5× and lowest at 50×. Titanium, zirconia, and glass-ceramic showed significant measured roughness values from 5× to 50×. Denture base material and composite had lower measured roughness values, especially after polishing. Line and area roughness varied significantly, indicating that magnification affects measured values. Standardizing magnifications is essential to ensure comparability between studies. A 50× magnification captures more detailed profile information while masking larger defects. Full article
(This article belongs to the Special Issue Recent Advances in Biomaterials for Restorative and Implant Dentistry)
Show Figures

Figure 1

Figure 1
<p>Trend of the mean roughness parameters R<sub>a</sub>/S<sub>a</sub> and R<sub>z</sub>/S<sub>z</sub> (μm) in relation to magnification (overview of <span class="underline">all</span> materials). The summarized data show the trend of reduced roughness with increasing magnification.</p>
Full article ">Figure 2
<p>Examples of titanium surfaces with diamond treatment and polishing from 5× to 50× magnification, with an exaggerated example of the roughness profile to illustrate the effect of magnification.</p>
Full article ">Figure 3
<p>Titanium: mean values and standard deviations of R<sub>a</sub>/S<sub>a</sub> and R<sub>z</sub>/S<sub>z</sub> (μm) in relation to different surface treatments and magnifications (5× to 50×)—titanium (mean values are shown above the bars).</p>
Full article ">Figure 4
<p>Zirconia: mean values and standard deviations of R<sub>a</sub>/S<sub>a</sub> and R<sub>z</sub>/S<sub>z</sub> (μm) in relation to different surface treatments and magnifications (5× to 50×)—zirconia (mean values are shown above the bars).</p>
Full article ">Figure 5
<p>Glass-ceramic: mean values and standard deviations of R<sub>a</sub>/S<sub>a</sub> and R<sub>z</sub>/S<sub>z</sub> (μm) in relation to different surface treatments and magnifications (5× to 50×)—glass-ceramic (mean values are shown above the bars).</p>
Full article ">Figure 6
<p>Denture base material: mean values and standard deviations of R<sub>a</sub>/S<sub>a</sub> and R<sub>z</sub>/S<sub>z</sub> (μm) in relation to different surface treatments and magnifications (5× to 50×)—denture base material (mean values are shown above the bars).</p>
Full article ">Figure 7
<p>Composite: mean values and standard deviations of R<sub>a</sub>/S<sub>a</sub> and R<sub>z</sub>/S<sub>z</sub> (μm) in relation to different surface treatments and magnifications (5× to 50×)—composite (mean values are shown above the bars).</p>
Full article ">
15 pages, 2266 KiB  
Article
Optimizing Cement Content in Controlled Low-Strength Soils: Effects of Water Content and Hydration Time
by Yilian Luo, Liangwei Jiang, Libing Qin, Qiang Luo, David P. Connolly and Tengfei Wang
Materials 2024, 17(23), 5915; https://doi.org/10.3390/ma17235915 - 3 Dec 2024
Viewed by 577
Abstract
The Ethylene Diamine Tetra-acetic Acid (EDTA) titration test is widely used for determining cement content, but its reliability is influenced by the hydration process of cement, which is affected by factors such as water content and hydration time. Despite their importance, these factors [...] Read more.
The Ethylene Diamine Tetra-acetic Acid (EDTA) titration test is widely used for determining cement content, but its reliability is influenced by the hydration process of cement, which is affected by factors such as water content and hydration time. Despite their importance, these factors have received limited attention in existing research. This study explores the relationships between the volume of titrant required for stabilization, cement content, water content, and hydration time. Using a regression orthogonal test, the primary and secondary relationships, as well as the interdependencies among these factors, are analyzed. Results reveal a negative linear relationship between the titrant volume and both water content and hydration time. Cement content, water content, and hydration time are identified as the most significant factors, with minimal interdependencies observed. Within the test parameters, calculated values exhibit an error margin below 2.4%. Deviations of 2.9% in water content and 86 min in hydration time correspond to an approximate 0.5% change in cement content. These findings offer valuable insights for optimizing cement content detection in Controlled Low-Strength Material (CLSM) mixes, promoting more sustainable construction practices. Full article
Show Figures

Figure 1

Figure 1
<p>EDTA titration test: (<b>a</b>) Procedure; (<b>b</b>) Reagent preparation; (<b>c</b>) Phenomena observed during testing.</p>
Full article ">Figure 2
<p>Orthogonal experimental design.</p>
Full article ">Figure 3
<p>Relationship between volume of titrant used (<span class="html-italic">V</span>) and cement content (<span class="html-italic">C</span>).</p>
Full article ">Figure 4
<p>Relationship between volume of titrant used (<span class="html-italic">V</span>) and water content (<span class="html-italic">W</span>).</p>
Full article ">Figure 5
<p>Relationship between volume of titrant used (<span class="html-italic">V</span>) and hydration time (<span class="html-italic">T</span>).</p>
Full article ">Figure 6
<p>Variation in cement content detection error (Δ<span class="html-italic">c</span>) with changes in water content (Δ<span class="html-italic">w</span>) and hydration time (Δ<span class="html-italic">t</span>).</p>
Full article ">
19 pages, 10254 KiB  
Article
Humidity Resistant Biodegradable Starch Foams Reinforced with Polyvinyl Butyral (PVB) and Chitosan
by Apoorva Kulkarni, Jakob Emrich and Ramani Narayan
Polymers 2024, 16(23), 3402; https://doi.org/10.3390/polym16233402 - 3 Dec 2024
Viewed by 892
Abstract
In this study, water-insoluble, moisture-resistant starch foams were prepared using an optimized one-step extrusion-foaming process in a ZSK-30 twin screw extruder. The extrusion parameters, including temperature, screw configuration, die diameter, water content, and feeding rates, were optimized to achieve foams with the lowest [...] Read more.
In this study, water-insoluble, moisture-resistant starch foams were prepared using an optimized one-step extrusion-foaming process in a ZSK-30 twin screw extruder. The extrusion parameters, including temperature, screw configuration, die diameter, water content, and feeding rates, were optimized to achieve foams with the lowest density and controlled expansion. A screw configuration made up of three kneading sections was found to be the most effective for better mixing and foaming. Polyvinyl butyral (PVB) acted as a plasticizer, resulting in foams with a density of 21 kg/m3 and an expansion ratio of 38.7, while chitosan served as a nucleating agent, reducing cell size and promoting a uniform cell size distribution. The addition of PVB and chitosan reduced the moisture sensitivity of the foams, rendering them hydrophobic and water-insoluble. The contact angle increased from 0° for control foams to 101.5° for foams containing 10% chitosan and 10% PVB. Confocal laser scanning microscopy (CLSM) confirmed the migration of chitosan to the foam surface, enhancing hydrophobicity. Aqueous biodegradation tests, conducted at 30 °C in accordance with ISO 14852 standards, demonstrated that despite enhanced moisture resistance, the foams remained readily biodegradable, achieving approximately 80% biodegradation within 80 days. These modified starch foams present a sustainable solution for packaging and insulation applications that demand long-term humidity resistance. Full article
(This article belongs to the Collection Polymeric Foams)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Structure of polyvinyl butyraldehyde (PVB).</p>
Full article ">Figure 2
<p>Experimental setup for foam extrusion.</p>
Full article ">Figure 3
<p>Foams obtained from (<b>a</b>) screw configuration #1, (<b>b</b>) screw configuration #2, and (<b>c</b>) second screw configuration used for foam production.</p>
Full article ">Figure 4
<p>Three strand dies used for extrusion and their corresponding expansion ratios.</p>
Full article ">Figure 5
<p>Effect of talc, PVOH, chitosan, and PVB on density and expansion ratio of starch foams.</p>
Full article ">Figure 6
<p>(<b>a</b>) SEM image of the fractured surface for control starch foam (no additives) and (<b>b</b>) cell size distribution of the foam.</p>
Full article ">Figure 7
<p>SEM images of starch foams containing (<b>a</b>) 0% talc, (<b>b</b>) 0.7% talc, (<b>c</b>) 2% talc, (<b>d</b>) 4% chitosan, 10% PVB, (<b>e</b>) 7% chitosan, 10% PVB, (<b>f</b>) 10% chitosan, 10% PVB, and SEM of, (<b>g</b>) talc, and (<b>h</b>) chitosan.</p>
Full article ">Figure 8
<p>Cell size distribution of foams containing (<b>a</b>) 0% talc, (<b>b</b>) 0.7% talc, (<b>c</b>) 2% talc, (<b>d</b>) 4% chitosan, 10% PVB, (<b>e</b>) 7% chitosan, 10% PVB, and (<b>f</b>) 10% chitosan, 10% PVB.</p>
Full article ">Figure 9
<p>Effect of various additives on water penetration of foams.</p>
Full article ">Figure 10
<p>Water solubility testing for starch foams.</p>
Full article ">Figure 11
<p>Moisture absorption curves for starch foams in different RH conditions (<b>a</b>) control foams (starch + water), (<b>b</b>) PVOH + chitosan + water, and (<b>c</b>) starch + PVB + chitosan.</p>
Full article ">Figure 12
<p>(<b>a</b>) moisture content at equilibrium for different foam formulations at 95% RH. (<b>b</b>) shrinkage observed in foams when placed in 95% RH environment.</p>
Full article ">Figure 13
<p>Effect of different additives on surface hydrophobicity of foams.</p>
Full article ">Figure 14
<p>CLSM 3D MIP images for 0%, 4%, 7%, and 10% chitosan foam formulations from the bulk of the sample (<b>a</b>–<b>d</b>) and from the surface (<b>e</b>–<b>h</b>). Schematic for interaction between the amino or OH groups of chitosan and OH groups of starch.</p>
Full article ">Figure 15
<p>Compressive strength of starch foams (1) Control foams (starch + water), (2) control foams (PVOH), (3) 10% PVB, 4% chitosan, (4) 10% PVB, 7% chitosan, and (5) 10% PVB, 10% chitosan.</p>
Full article ">Figure 16
<p>Aqueous biodegradation curves for control starch foam, PVB, and chitosan containing foam and cellulose.</p>
Full article ">
19 pages, 8386 KiB  
Article
Eradication of Biofilms on Catheters: Potentials of Tamarix ericoides Rottl. Bark Coating in Preventing Catheter-Associated Urinary Tract Infections (CAUTIs)
by Mohammed H. Karrar Alsharif, Muhammad Musthafa Poyil, Salman Bin Dayel, Mohammed Saad Alqahtani, Ahmed Abdullah Albadrani, Zainab Mohammed M. Omar, Abdullah MR. Arafah, Tarig Gasim Mohamed Alarabi, Reda M. Fayyad and Abd El-Lateef Saeed Abd El-Lateef
Life 2024, 14(12), 1593; https://doi.org/10.3390/life14121593 - 3 Dec 2024
Viewed by 703
Abstract
Catheter-associated urinary tract infections (CAUTIs) cause serious complications among hospitalized patients due to biofilm-forming microorganisms which make treatment ineffective by forming antibiotic-resistant strains. As most CAUTI-causing bacterial pathogens have already developed multidrug resistance, there is an urgent need for alternative antibacterial agents to [...] Read more.
Catheter-associated urinary tract infections (CAUTIs) cause serious complications among hospitalized patients due to biofilm-forming microorganisms which make treatment ineffective by forming antibiotic-resistant strains. As most CAUTI-causing bacterial pathogens have already developed multidrug resistance, there is an urgent need for alternative antibacterial agents to prevent biofilms on catheter surfaces. As a trial to find out such a potential agent of natural origin, the bark of Tamarix ericoides Rottl., a little-known plant from the Tamaricaceae family, was examined for its antibacterial and antibiofilm activities against one of the major, virulent, CAUTI-causing bacterial pathogens: Enterococcus faecalis. The methanolic T. ericoides bark extract was analyzed for its antibacterial activity using the well diffusion method and microdilution method. Killing kinetics were calculated using time–kill assay, and the ability of biofilm formation and its eradication upon treatment with the T. ericoides bark extract was studied by crystal violet assay. GC-MS analysis was performed to understand the phytochemical presence in the extract. A in vitro bladder model study was performed using extract-coated catheters against E. faecalis, and the effect was visualized using CLSM. The changes in the cell morphology of the bacterium after treatment with the T. ericoides bark extract were observed using SEM. The biocompatibility of the extract towards L929 cells was studied by MTT assay. The anti-E. faecalis activity of the extract-coated catheter tube was quantified by viable cell count method, which exposed 20% of growth after five days of contact with E. faecalis. The anti-adhesive property of the T. ericoides bark extract was studied using CLSM. The extract showed potential antibacterial activity, and the lowest inhibitory concentration needed to inhibit the growth of E. faecalis was found to be 2 mg/mL. The GC-MS analysis of the methanolic fractions of the T. ericoides bark extract revealed the presence of major phytochemicals, such as diethyl phthalate, pentadecanoic acid, methyl 6,11-octadecadienoate, cyclopropaneoctanoic acid, 2-[(2-pentylcyclopropyl) methyl]-, methyl ester, erythro-7,8-bromochlorodisparlure, etc., that could be responsible for the antibacterial activity against E. faecalis. The killing kinetics of the extract against E. faecalis was calculated and the extract showed promising antibiofilm activity on polystyrene surfaces. The T. ericoides bark extract effectively reduced the E. faecalis mature biofilms by 75%, 82%, and 83% after treatment with 1X MIC (2 mg/mL), 2X MIC (4 mg/mL), and 3X MIC (6 mg/mL) concentrations, respectively, which was further confirmed by SEM analysis. The anti-adhesive property of the T. ericoides bark extract studied using CLSM revealed a reduction in the biofilm thickness, and the FDA and PI combination revealed the death of 80% of the cells on the extract-coated catheter tube. In addition, SEM analysis showed extensive damage to the E. faecalis cells after the T. ericoides bark extract treatment, and it was not cytotoxic. Hence, after further studies, T. ericoides bark extract with potential antibacterial, antibiofilm, and anti-adhesive activities can be developed as an alternative agent for treating CAUTIs. Full article
Show Figures

Figure 1

Figure 1
<p>GC-MS chromatogram of methanolic <span class="html-italic">T. ericoides</span> bark extract.</p>
Full article ">Figure 2
<p>Antibacterial activity of <span class="html-italic">T. ericoides</span> bark methanolic extract against <span class="html-italic">E. faecalis.</span> Note: P—positive control and V—vehicle control.</p>
Full article ">Figure 3
<p>Graph showing the MIC of <span class="html-italic">T. ericoides</span> bark methanolic extract against <span class="html-italic">E. faecalis</span>.</p>
Full article ">Figure 4
<p>Killing kinetics <span class="html-italic">T. ericoides</span> bark extract against <span class="html-italic">E. faecalis</span> (noted at 1 h treatment).</p>
Full article ">Figure 5
<p>A graph showing the impact of <span class="html-italic">T. ericoides</span> bark extract on <span class="html-italic">E. faecalis</span> biofilm formation. The inhibition of biofilm was noted until the MIC (2 mg/mL).</p>
Full article ">Figure 6
<p>The effect of <span class="html-italic">T. ericoides</span> bark extract on the mature biofilms of <span class="html-italic">E. faecalis</span> was studied qualitatively using SEM. (<b>A</b>) Numerous viable cells adhered to the cellulose matrix. (<b>B</b>) 2 mg/mL of the <span class="html-italic">T. ericoides</span> bark extract treatment revealed a reduction in mature biofilms on the matrix. Scale bar—2 µm.</p>
Full article ">Figure 7
<p>The effect of <span class="html-italic">T. ericoides</span> bark extract on the mature biofilms of <span class="html-italic">E. faecalis</span> was studied quantitatively using crystal violet assay, and the graph presents the percentage of biofilm eradication after treatments with three concentrations of <span class="html-italic">T. ericoides</span> bark extract. Note: PC—positive control.</p>
Full article ">Figure 8
<p>The antibacterial activity of the <span class="html-italic">T. ericoides</span> bark extract-coated catheter tube against the <span class="html-italic">E. faecalis</span> was investigated. The formation of a growth inhibition zone around the catheter coated with an extract tube against the <span class="html-italic">E. faecalis</span> is visible. Note: C—<span class="html-italic">T. ericoides</span> bark extract-coated tube; U—uncoated tube.</p>
Full article ">Figure 9
<p>Quantification of <span class="html-italic">E. faecalis</span> load from <span class="html-italic">T. ericoides</span> bark extract-coated and uncoated catheter tube using viable count method. (<b>A</b>) Uncoated catheter tube produced greater number of CFUs. (<b>B</b>) Catheter coated with <span class="html-italic">T. ericoides</span> bark extract produced fewer CFUs. (<b>C</b>) Graph representing growth percentage calculated in catheter coated with <span class="html-italic">T. ericoides</span> bark extract. *** Highly significant.</p>
Full article ">Figure 10
<p>Biofilm visualization after staining with FDA and PI using CLSM (<b>A</b>) Visualization of biofilm formation on uncoated catheter, observed after 5 days of contact with <span class="html-italic">E. faecalis</span>. (<b>B</b>) Three-dimensional structure of biofilm formation on uncoated catheter surface, representing 18 µm thickness. (<b>C</b>) Visualization of biofilm formation on <span class="html-italic">T. ericoides</span> bark extract-coated catheter, observed after 5 days of contact with <span class="html-italic">E. faecalis</span>. (<b>D</b>) Three-dimensional view exposes reduction in biofilm thickness to 14 µm. Scale bar: 50 µm.</p>
Full article ">Figure 11
<p>Based on the FDA and PI combination, the live and dead cell percentage was calculated from the uncoated and coated catheter tubes that were in contact with <span class="html-italic">E. faecalis</span> cells for 5 days and showed that 80% of cells were dead in the <span class="html-italic">T. ericoides</span> bark extract-coated catheter tube.</p>
Full article ">Figure 12
<p>The effect of <span class="html-italic">T. ericoides</span> bark extract on <span class="html-italic">E. faecalis</span> cell morphology (<b>A</b>) <span class="html-italic">E. faecalis</span> cells without treatment showed smooth and undamaged cell surfaces. (<b>B</b>) Red arrows point <span class="html-italic">E. faecalis</span> cells which showed ballooning and cell shrinkage after treatment with <span class="html-italic">T. ericoides</span> bark extract.</p>
Full article ">Figure 13
<p>Cytotoxic effect of <span class="html-italic">T. ericoides</span> bark extract on L<sub>929</sub> cells. (<b>A</b>) Untreated L<sub>929</sub> cells. (<b>B</b>) L<sub>929</sub> cells treated with <span class="html-italic">T. ericoides</span> bark extract. (<b>C</b>) Graph representing the cell viability percentage after various concentrations.</p>
Full article ">
28 pages, 12654 KiB  
Article
Investigating the Antibacterial, Antioxidant, and Anti-Inflammatory Properties of a Lycopene Selenium Nano-Formulation: An In Vitro and In Vivo Study
by Reem Binsuwaidan, Thanaa A. El-Masry, Maysa M. F. El-Nagar, Enas I. El Zahaby, Mohamed M. S. Gaballa and Maisra M. El-Bouseary
Pharmaceuticals 2024, 17(12), 1600; https://doi.org/10.3390/ph17121600 - 27 Nov 2024
Viewed by 834
Abstract
Background: The potent antioxidant lycopene has attracted a large amount of research attention given its potential health benefits. We aimed to assess the antimicrobial, anti-inflammatory, and antioxidant properties of lycopene (Lyc), selenium nanoparticles (Se-NPs), and lycopene selenium nanoparticles (Lyc-Se-NPs). Methods: FTIR, polydispersity index, [...] Read more.
Background: The potent antioxidant lycopene has attracted a large amount of research attention given its potential health benefits. We aimed to assess the antimicrobial, anti-inflammatory, and antioxidant properties of lycopene (Lyc), selenium nanoparticles (Se-NPs), and lycopene selenium nanoparticles (Lyc-Se-NPs). Methods: FTIR, polydispersity index, and zeta potential evaluations provided a complete characterization of the synthesized Lyc-Se-NPs. The broth dilution method and a crystal violet microtiter plate assay were employed to assess the antibacterial and antibiofilm activity, respectively. The rat wound infection model was performed to study the anti-inflammatory effect. Findings: The Lyc-Se-NPs had a zeta potential range of −16.93 to −31.04 mV and a mean particle size of 126.6 ± 3.12 nm. All peaks’ percentage transmittance decreased, according to the FTIR analysis of the Lyc-Se-NPs, with the exception of one peak at 2924.22 cm−1, which is suggestive of C-H stretching. The mean scavenging concentrations for Lyc-Se-NPs in the DPPH and ABTS radical scavenging experiments were 3.85 ± 0.65 and 4.26 ± 0.7 µg/mL, respectively. For S. aureus, the Lyc-Se-NPs’ MIC values varied from 64 to 1024 µg/mL. CLSM verified that S. aureus treated with sub-MICs of Lyc-Se-NPs showed a significant reduction in biofilm formation. Furthermore, the group treated with 50 mg of Lyc-Se-NPs showed the quickest rate of wound healing. They demonstrated a notable elevation of the HO−1 content in skin tissues, together with the greatest downregulation of TNF-α, IL-1β, and COX-2. Conclusions: The distinguishing features of Lyc-Se-NPs reveal that this unique compound is a promising antibacterial, antioxidant, and anti-inflammatory agent. Full article
(This article belongs to the Special Issue Bioactive Compounds Derived from Plants and Their Medicinal Potential)
Show Figures

Figure 1

Figure 1
<p>(<b>A</b>) SEM of lycopene (<b>a</b>), selenium nanoparticles (<b>b</b>), and selenium/lycopene nanoparticles (<b>c</b>), and TEM of selenium/lycopene nanoparticles (<b>d</b>). (<b>B</b>) FTIR of lycopene and selenium/lycopene nanoparticles (<b>a</b>), and FTIR of Selenium nanoparticles (<b>b</b>).</p>
Full article ">Figure 1 Cont.
<p>(<b>A</b>) SEM of lycopene (<b>a</b>), selenium nanoparticles (<b>b</b>), and selenium/lycopene nanoparticles (<b>c</b>), and TEM of selenium/lycopene nanoparticles (<b>d</b>). (<b>B</b>) FTIR of lycopene and selenium/lycopene nanoparticles (<b>a</b>), and FTIR of Selenium nanoparticles (<b>b</b>).</p>
Full article ">Figure 2
<p>The antioxidant activity of free Se-NPs, lycopene, and Lyc-Se-NPs, evaluated by a DPPH radical scavenging assay (<b>A</b>) and ABTS radical scavenging assay (<b>B</b>). Results are expressed as the mean ± SD (<span class="html-italic">n</span> = 3). Control: ascorbic acid, Se-NPs: selenium nanoparticles. * Significant vs. control group (ascorbic acid) per each concentration (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 2 Cont.
<p>The antioxidant activity of free Se-NPs, lycopene, and Lyc-Se-NPs, evaluated by a DPPH radical scavenging assay (<b>A</b>) and ABTS radical scavenging assay (<b>B</b>). Results are expressed as the mean ± SD (<span class="html-italic">n</span> = 3). Control: ascorbic acid, Se-NPs: selenium nanoparticles. * Significant vs. control group (ascorbic acid) per each concentration (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 3
<p>Growth curve of <span class="html-italic">S. aureus</span> (S16) clinical isolate cultured in the absence and presence of ½, ¼, and ⅛ MICs of tested compounds at different time intervals.</p>
Full article ">Figure 4
<p>CLSM of <span class="html-italic">S. aureus</span> (S16) clinical isolate to detect biofilm thickness pre- and post-treatment with ¼ MIC of the tested compounds. (<b>A</b>) Untreated <span class="html-italic">S. aureus</span> biofilm. (<b>B</b>) Lyc-treated biofilm. (<b>C</b>) Selenium-treated biofilm. (<b>D</b>) Lyc-Se-NP-treated biofilm.</p>
Full article ">Figure 5
<p>Change in fluorescence intensity with change in viability pre- and post-treatment with ¼ MIC of the tested compounds. * Significant vs. untreated group (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 6
<p>Experimental study of a rat wound-healing model untreated or after treatment with the standard, lycopene only, free Se-NPs, Lyc-Se-NPs (25 mg), or Lyc-Se-NPs (50 mg). The untreated group (<b>A2</b>,<b>A4</b>,<b>A7</b>) exhibited larger wound areas compared to the gentamicin (<b>B2</b>,<b>B4</b>,<b>B7</b>), lycopene-only (<b>C2</b>,<b>C4</b>,<b>C7</b>), free Se-NP (<b>D2</b>,<b>D4</b>,<b>D7</b>), Lyc-Se-NP (25 mg) (<b>E2</b>,<b>E4</b>,<b>E7</b>), and Lyc-Se-NP (50 mg) (<b>F2</b>,<b>F4</b>,<b>F7</b>) groups.</p>
Full article ">Figure 7
<p>Impacts of different treatments on contents of inflammatory markers TNF-α (<b>A</b>), IL-1β (<b>B</b>), and COX-2 (<b>C</b>) in skin tissues. Data were recorded as mean ± SD (<span class="html-italic">n</span> = 6). * Significant vs. untreated group, <sup>#</sup> significant vs. gentamicin group, <sup>a</sup> significant vs. lycopene-only group, <sup>b</sup> significant vs. free Se-NP group, and <sup>c</sup> Lyc-Se-NPs (25 mg). Se-NPs: selenium nanoparticles. Each group differed significantly from the others at <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 7 Cont.
<p>Impacts of different treatments on contents of inflammatory markers TNF-α (<b>A</b>), IL-1β (<b>B</b>), and COX-2 (<b>C</b>) in skin tissues. Data were recorded as mean ± SD (<span class="html-italic">n</span> = 6). * Significant vs. untreated group, <sup>#</sup> significant vs. gentamicin group, <sup>a</sup> significant vs. lycopene-only group, <sup>b</sup> significant vs. free Se-NP group, and <sup>c</sup> Lyc-Se-NPs (25 mg). Se-NPs: selenium nanoparticles. Each group differed significantly from the others at <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 8
<p>Impacts of different treatments on anti-inflammatory marker (HO-1) content in skin tissues. Data were recorded as mean ± SD (<span class="html-italic">n</span> = 6). * Significant vs. untreated group, <sup>#</sup> significant vs. gentamicin group, <sup>a</sup> significant vs. lycopene-only group, <sup>b</sup> significant vs. free Se-NP group, and <sup>c</sup> Lyc-Se-NPs (25 mg). Se-NPs: selenium nanoparticles. Each group differed significantly from the others at <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 9
<p>Histopathological examination of wound healing and tissue integrity across different study groups. In the untreated group (<b>A1</b>,<b>A2</b>), delayed wound healing is evident, characterized by persistent fibrin deposition, absence of granulation tissue, and extensive inflammatory cell infiltration. The epidermis shows necrotic areas and disrupted epithelial integrity, while the dermis exhibits severe inflammatory infiltration with neutrophils and macrophages. The gentamicin group (<b>B1</b>,<b>B2</b>) demonstrates advanced healing with initial granulation tissue formation and early collagen deposition. The epidermis displays moderate re-epithelialization, and the dermis shows a significantly reduced inflammatory response. In the lycopene-only group (<b>C1</b>,<b>C2</b>), mild preservation of epidermal architecture and reduced necrosis can be observed. Enhanced granulation tissue formation and improved collagen organization indicate accelerated wound closure. The free Se-NP group (<b>D1</b>,<b>D2</b>) similarly shows preserved epidermal layers, mild inflammatory infiltrate (predominantly lymphocytic), and increased vascularization and collagen synthesis at the wound site, suggesting improved early tissue repair. The Lyc-Se-NP (25 mg) group (<b>E1</b>,<b>E2</b>) exhibits intact epidermal layers, minimal necrosis, and a balanced inflammatory response with robust granulation tissue and collagen remodeling, reflecting the synergistic effects of the treatment. In the Lyc-Se-NP (50 mg) group (<b>F1</b>,<b>F2</b>), the skin structure is well organized with complete preservation of epidermal layers and advanced wound closure. Dense collagen bundles and mature vascular networks are prominent, indicating the optimal therapeutic efficacy of the high-dose combination. Scab (S), granulation tissue (g), dermis (d), epidermis (p), inflammatory cells (m), and arrow mark for neovascularization (red arrow), fibroblast infiltration (black arrow), and fibrous tissue (green arrow)).</p>
Full article ">Figure 10
<p>Histopathological assessment of wound healing across different treatments. The untreated group (<b>A1</b>,<b>A2</b>) exhibits a disrupted epidermal structure, poor collagen deposition, and disorganized fibers, reflecting inadequate wound repair. The gentamicin (<b>B1</b>,<b>B2</b>) group shows partial preservation of the epidermis, initial collagen deposition, and improved granulation tissue organization, indicating better healing. The lycopene-only group (<b>C1</b>,<b>C2</b>) has enhanced epidermal preservation and improved collagen organization, suggesting accelerated wound repair. The free Se-NP group (<b>D1</b>,<b>D2</b>) demonstrates an intact epidermis, minimal necrosis, and improved collagen synthesis. The Lyc-Se-NP (25 mg) group (<b>E1</b>,<b>E2</b>) shows complete epidermal preservation, robust granulation, and dense collagen bundles, indicating a synergistic effect of the treatments. The Lyc-Se-NP (50 mg) group (<b>F1</b>,<b>F2</b>) exhibits optimal healing with a well-preserved epidermis, advanced collagen deposition, and mature vascular networks, underscoring the efficacy of the high-dose combination. (p) epidermis, (d) dermis, (hf) hair follicles, (sg) sebaceous gland, (cb) collagen bundles, (S) scab.</p>
Full article ">Figure 11
<p>Dermal collagen (%) of skin sections. Data were recorded as mean ± SD (<span class="html-italic">n</span> = 6). * Significant vs. untreated group, <sup>#</sup> significant vs. gentamicin group, <sup>a</sup> significant vs., lycopene-only group, <sup>b</sup> significant vs. free Se-NP group, and <sup>c</sup> Lyc-Se-NPs (25 mg). Se-NPs: selenium nanoparticles. Each group differed significantly from the others at <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 12
<p>Analysis of NF-κB-p65 activation across different treatment groups. (<b>A1</b>,<b>A2</b>) show the untreated group with marked NF-κB-p65 activation, characterized by the highest staining and expression scores, indicating robust NF-κB activity. (<b>B1</b>,<b>B2</b>) depict the gentamicin group with mild NF-κB-p65 activation, evidenced by lower staining and expression levels, reflecting a partial response. (<b>C1</b>,<b>C2</b>) illustrate the effect of lycopene only, while (<b>D1</b>,<b>D2</b>) showed the effect of free Se-NPs, both resulting in moderate NF-κB-p65 activation with reduced staining and expression scores. (<b>E1</b>,<b>E2</b>) present the Lyc-Se-NP (25 mg) group, which further reduced NF-κB-p65 activation but not as effectively as the Lyc-Se-NP (50 mg) group. Finally, (<b>F1</b>,<b>F2</b>) demonstrate the Lyc-Se-NP (50 mg) group, with the lowest NF-κB-p65 activation, characterized by minimal staining and expression levels, indicating effective suppression of NF-κB-p65 activity. Black arrows indicate positive immunohistochemical expression.</p>
Full article ">
18 pages, 3967 KiB  
Article
Occurrence, Antibiotic Resistance and Biofilm-Forming Ability of Listeria monocytogenes in Chicken Carcasses and Cuts
by Sarah Panera-Martínez, Rosa Capita, Ángela Pedriza-González, María Díez-Moura, Félix Riesco-Peláez and Carlos Alonso-Calleja
Foods 2024, 13(23), 3822; https://doi.org/10.3390/foods13233822 - 27 Nov 2024
Viewed by 912
Abstract
A total of 104 samples of chicken meat acquired on the day of slaughter from two slaughterhouses in northwestern Spain were analyzed. These comprised 26 carcasses and 26 cuts from each of the two establishments. An average load of 5.39 ± 0.61 log [...] Read more.
A total of 104 samples of chicken meat acquired on the day of slaughter from two slaughterhouses in northwestern Spain were analyzed. These comprised 26 carcasses and 26 cuts from each of the two establishments. An average load of 5.39 ± 0.61 log10 cfu/g (total aerobic counts) and 4.90 ± 0.40 log10 cfu/g (psychrotrophic microorganisms) were obtained, with differences (p < 0.05) between types of samples and between slaughterhouses. Culturing methods involving isolation based on the UNE-EN-ISO 11290-1:2018 norm and identification of isolates by polymerase chain reaction (PCR) to detect the lmo1030 gene allowed the detection of Listeria monocytogenes in 75 samples (72.1% of the total; 50.0% of the carcasses and 94.2% of the cuts). The 75 isolates, one for each positive sample, were tested for resistance against a panel of 15 antibiotics of clinical interest by the disc diffusion method. All isolates belonged to the serogroup IIa (multiplex PCR assay) and showed resistance to between four and ten antibiotics, with an average value of 5.7 ± 2.0 resistances per isolate, this rising to 7.0 ± 2.1 when strains with resistance and reduced susceptibility were taken together. A high prevalence of resistance was observed for antibiotics belonging to the cephalosporin and quinolone families. However, the level of resistance was low for antibiotics commonly used to treat listeriosis (e.g., ampicillin or gentamicin). Nine different resistance patterns were noted. One isolate with each resistance pattern was tested for its ability to form biofilms on polystyrene during 72 h at 12 °C. The total biovolume of the biofilms registered through confocal laser scanning microscopy (CLSM) in the observation field of 16,078.24 μm2 ranged between 13,967.7 ± 9065.0 μm3 and 33,478.0 ± 23,874.1 μm3, and the biovolume of inactivated bacteria between 0.5 ± 0.4 μm3 and 179.1 ± 327.6 μm3. A direct relationship between the level of resistance to antibiotics and the ability of L. monocytogenes strains to form biofilms is suggested. Full article
(This article belongs to the Section Food Microbiology)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Prevalence of <span class="html-italic">Listeria monocytogenes</span> by type of sample (carcasses or cuts) and slaughterhouse (A or B).</p>
Full article ">Figure 2
<p>Percentage of <span class="html-italic">Listeria monocytogenes</span> isolates with resistance, reduced susceptibility or susceptibility to each antibiotic tested. Antibiotics (the data from the two slaughterhouses are compared separately) that do not share any letters present significant differences one from another (<span class="html-italic">p</span> &lt; 0.05). AMP (ampicillin; 10 µg), OX (oxacillin; 1 µg), FOX (cefoxitin; 30 µg), CTX (cefotaxime; 30 µg), FEP (cefepime; 30 µg), CN (gentamycin; 10 µg), E (erythromycin; 15 µg), VA (vancomycin; 30 µg), SXT (trimethoprim-sulfamethoxazole; 25 µg), RD (rifampicin; 5 µg), TE (tetracycline; 30 µg), C (chloramphenicol; 30 µg), CIP (ciprofloxacin; 5 µg), ENR (enrofloxacin; 5 µg), F (nitrofurantoin; 300 µg).</p>
Full article ">Figure 3
<p>Total biovolume (green bars; left-side <span class="html-italic">y</span>-axis) and biovolume of inactivated bacteria (red line; right-side <span class="html-italic">y</span>-axis) of the biofilms formed on polystyrene (72 h at 12 °C) for each <span class="html-italic">Listeria monocytogenes</span> isolate tested. Data (total biovolume and biovolume of inactivated bacteria were compared separately) with no letters in common are significantly different (<span class="html-italic">p</span> &lt; 0.05). One isolate from each of the resistance phenotypes was studied: (1) OX-FOX-CTX-FEP; (2) OX-FOX-CTX-FEP-RD; (3) OX-FOX-CTX-FEP-CIP; (4) OX-FOX-CTX-FEP-SXT; (5) OX-FOX-CTX-FEP-SXT-RD; (6) OX-FOX-CTX-FEP-CIP-ENR; (7) OX-FOX-CTX-FEP-CN-E-RD-TE; (8) OX-FOX-CTX-FEP-CN-E-SXT-RD-TE; (9) OX-FOX-CTX-FEP-CN-E-SXT-RD-TE-CIP. OX (oxacillin; 1 µg), FOX (cefoxitin; 30 µg), CTX (cefotaxime; 30 µg), FEP (cefepime; 30 µg), CN (gentamycin; 10 µg), E (erythromycin; 15 µg), SXT (trimethoprim-sulfamethoxazole; 25 µg), RD (rifampicin; 5 µg), TE (tetracycline; 30 µg), CIP (ciprofloxacin; 5 µg), ENR (enrofloxacin; 5 µg).</p>
Full article ">Figure 4
<p>Three-dimensional reconstructions of the biofilms formed on polystyrene (72 h; 12 °C) by <span class="html-italic">Listeria monocytogenes</span> isolates of different antibiotic resistance patterns. The total biovolume (μm<sup>3</sup>) observed by SYTO9 green staining is not in parentheses, while the biovolume (μm<sup>3</sup>) of inactivated bacteria observed after PI red staining is shown in parentheses. The images (126.8 μm × 126.8 μm) were reconstructed with the IMARIS 9.1 program, with virtual projections of the shadow on the right. OX (oxacillin; 1 µg), FOX (cefoxitin; 30 µg), CTX (cefotaxime; 30 µg), FEP (cefepime; 30 µg), CN (gentamycin; 10 µg), E (erythromycin; 15 µg), SXT (trimethoprim-sulfamethoxazole; 25 µg), RD (rifampicin; 5 µg), TE (tetracycline; 30 µg), CIP (ciprofloxacin; 5 µg), ENR (enrofloxacin; 5 µg).</p>
Full article ">
9 pages, 2519 KiB  
Article
Comparative Evaluation of Sodium Hypochlorite Gel Penetration Using Er,Cr:YSGG Laser and Passive Ultrasonic Activation After Apicoectomy: An In Vitro Study with Confocal Laser Scanning Microscopy
by Joseph Di Franco, Haitham Elafifi Ebeid, Pablo Betancourt, Antonio Pallarés-Sabater and Alberto Casino Alegre
J. Clin. Med. 2024, 13(23), 7050; https://doi.org/10.3390/jcm13237050 - 22 Nov 2024
Viewed by 689
Abstract
Background: Lasers from the erbium family have been investigated to activate irrigation with sodium hypochlorite (NaOCl), improving the disinfection depth of the dentinal tubules of the root canal walls during root canal treatment. However, the possibility of laser-activated irrigation (LAI) in retro-cavity preparation [...] Read more.
Background: Lasers from the erbium family have been investigated to activate irrigation with sodium hypochlorite (NaOCl), improving the disinfection depth of the dentinal tubules of the root canal walls during root canal treatment. However, the possibility of laser-activated irrigation (LAI) in retro-cavity preparation has not been investigated to the date. The aim of our experimental study is to evaluate the efficacy of NaOCl gel penetration inside the dentinal tubules when activated during retro-cavity preparation, comparing passive ultrasonic activation (PUI) and Er,Cr:YSGG LAI. Materials and Methods: Fifty extracted mature single-root human teeth were divided into four groups (control, PUI, and two LAI groups with different NaOCl concentrations). After conventional endodontic treatment and root end resection, NaOCl gel (impregnated with rhodamine dye for confocal laser scanning microscopy (CLSM) analysis) was applied and activated according to the study group. The penetration index and mean penetration length were measured using computer software. Results: Both penetration index and mean penetration length were found to have increased in the PUI group compared to the control samples. However, LAI had a better penetration that was statistically significant compared to both the PUI and control groups. The difference in NaOCl concentration in the laser groups did not affect the penetration values. Conclusions: Within the limitations of our in vitro study using NaOCl gel activation in the retro-cavity after apicectomy, Er,Cr:YSGG LAI significantly enhanced NaOCl gel penetration capacity compared to PUI, regardless of its concentration. LAI can enhance its penetration in a safe way, avoiding its extrusion to the surrounding periapical tissues. Full article
(This article belongs to the Special Issue Clinical Research of Novel Therapeutic Approaches in Dentistry)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) Retro-cavity preparation after apicectomy, (<b>b</b>) NaOCl (2.5%) gel application without activation (red arrow represents the NaOCl gel with rhodamine dye), (<b>c</b>) PUI of 2.5% NaOCl gel, (<b>d</b>) Er,Cr:YSGG LAI of 2.5% NaOCl gel, (<b>e</b>) Er,Cr:YSGG LAI of 0.5% NaOCl gel. (Authored by Dr. Elafifi).</p>
Full article ">Figure 2
<p>Representation of the measurement using Q-Path software. (<b>A</b>) various lines measuring the penetration depths all around the root canal to be able to determine the mean penetration depth; (<b>B</b>) a line defining all the penetration peaks and another line tracing the outer surface of the root to determine the penetration index.</p>
Full article ">Figure 3
<p>Sample confocal microscopy images of the different groups. The images represent the amount of penetration of the rhodamine dye from the root canal walls outwards towards the external root surface using different NaOCl gel activation protocols. (<b>A</b>–<b>D</b>) control group, (<b>B</b>–<b>E</b>) ultrasonic group, (<b>C</b>–<b>F</b>) laser group.</p>
Full article ">Figure 4
<p>Box plot of the statistical difference between groups in terms of the mean penetration depth (the * indicates that the difference in the results between these groups is statistically significant).</p>
Full article ">Figure 5
<p>Box plot of the statistical difference between groups in terms of penetration index (the * indicates that the difference in the results between these groups is statistically significant).</p>
Full article ">
Back to TopTop