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8 pages, 1066 KiB

Open AccessProceeding Paper

Comparison of the Effects of Essential Oils and Antibiotics on Listeria monocytogenes Isolates

by Vesna Kalaba, Dragica Đurđević-Milošević, Tanja Ilić and Dragana Kalaba

Eng. Proc. 2024, 81(1), 1; https://doi.org/10.3390/engproc2024081001 - 28 Nov 2024

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Food contamination with Listeria monocytogenes can cause health problems of increasing global concern. The resistance of L. monocytogenes to antibiotics requires finding alternative solutions to protect human health. This mini study was designed to evaluate the effects of antibiotics and some particular essential [...] Read more.

Food contamination with Listeria monocytogenes can cause health problems of increasing global concern. The resistance of L. monocytogenes to antibiotics requires finding alternative solutions to protect human health. This mini study was designed to evaluate the effects of antibiotics and some particular essential oils on L. monocytogenes isolates from food of animal origin and isolates from food-producing surfaces. This aim was to investigate the effects of seven antibiotics (amikacin, gentamicin, penicillin, cephalexin, ceftriaxone, tetracycline, and nalidixic acid) on L. monocytogenes isolated from food and surface samples. Also, the antibacterial activity of four essential oils (thyme, oregano, peppermint, and rosemary) against the growth of L. monocytogenes isolates was investigated. Listeria monocytogenes isolates were from food of an animal origin and food-producing surfaces. The isolation and determination of L. monocytogenes from food samples followed ISO 11290-1. Surface samplings were performed in compliance with ISO 18593, followed by the isolation and determination of L. monocytogenes. A disc diffusion method was used, and the tests were performed in triplicate. The results of this study confirmed the pronounced antibacterial activity of essential oils compared to antimicrobial drugs. The essential oil of Thymus vulgaris showed a bactericidal effect against all tested L. monocytogenes isolates. Full article

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8 pages, 3354 KiB

Open AccessProceeding Paper

Electrospun Hyaluronan-Based Nanofibers with Mangiferin: Preparation, Morphology, and Drug Release Kinetics

by Roman Shaikenov, Vladislava Klimshina, Yuliya Generalova, Polina Serbun, Anna Kosova, Maksim Dorogov, Svetlana Morozkina and Petr Snetkov

Eng. Proc. 2024, 81(1), 2; https://doi.org/10.3390/engproc2024081002 - 28 Nov 2024

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Abstract

The rise in antibiotic-resistant bacterial infections is a major global health concern. The search for natural compounds that inhibit the growth of pathogens is becoming urgent. One such compound is mangiferin, a non-toxic polyphenolic compound derived mainly from Mangifera indica. In addition [...] Read more.

The rise in antibiotic-resistant bacterial infections is a major global health concern. The search for natural compounds that inhibit the growth of pathogens is becoming urgent. One such compound is mangiferin, a non-toxic polyphenolic compound derived mainly from Mangifera indica. In addition to antibacterial properties, it exhibits anticancer, antioxidant, immunomodulatory, analgesic and other activities. However, the clinical application of mangiferin is limited by poor solubility and bioavailability. This study describes mangiferin-loaded electrospun nanofibers based on high-molecular-weight hyaluronic acid. The nanofibers improve mangiferin delivery and possess favorable morphological characteristics and drug release kinetics, making them promising candidates for effective antibacterial dressings. This study found that an increase in the mangiferin content of the fibers led to an increase in the average diameter of the fibers. It was also found that nanofibers with different mangiferin content have similar release kinetics with an anomalous non-Fickian transport pattern: most of the mangiferin is released within 10–15 min. Full article

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12 pages, 2109 KiB

Open AccessProceeding Paper

A Short Overview of the Formulation of Cellulose-Based Hydrogels and Their Biomedical Applications

by Raja Saadan, Aziz Ihammi, Mohamed Chigr and Ahmed Fatimi

Eng. Proc. 2024, 81(1), 3; https://doi.org/10.3390/engproc2024081003 - 20 Dec 2024

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Abstract

Cellulose, the most abundant natural biopolymer, has garnered significant attention for hydrogel development due to its exceptional properties, including biocompatibility, biodegradability, renewability, and mechanical strength. These attributes make cellulose an environmentally friendly and safe material for biomedical engineering applications. Crosslinking is a critical [...] Read more.

Cellulose, the most abundant natural biopolymer, has garnered significant attention for hydrogel development due to its exceptional properties, including biocompatibility, biodegradability, renewability, and mechanical strength. These attributes make cellulose an environmentally friendly and safe material for biomedical engineering applications. Crosslinking is a critical step in hydrogel synthesis, enabling the formation of a 3D network that enhances structural and functional properties. Various crosslinking methods have been employed to tailor cellulose-based hydrogels for specific applications, such as tissue engineering, wound healing, drug delivery, and 3D bioprinting. This paper provides a concise overview of the formulation techniques and biomedical applications of cellulose-based hydrogels. By synthesizing recent advances from the literature, we highlight the unique advantages of cellulose-based hydrogels over other biomaterials and discuss their potential as a sustainable and innovative platform in biomedical engineering. Full article

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The chemical structure of cellulose—a linear polymer composed of β-D-glucopyranose units covalently linked through (1→4) glycosidic bonds. (Reprinted from Chen et al., 2022 [<a href="#B10-engproc-81-00003" class="html-bibr">10</a>]. Copyright © 2022 MDPI under the terms and conditions of the Creative Commons Attribution license.) Full article ">Figure 2
Some properties of the developed chitosan/HPMC/glycerol hydrogel: (A) photographs of the hydrogel in sol (25 °C) and gel state (32 °C); (B) thermogelation properties; (C) in vitro cytotoxicity results after 48 h incubation. * Significant differences compared to the positive control (p < 0.01). (Reprinted and adapted with permission from Wang et al., 2016 [<a href="#B55-engproc-81-00003" class="html-bibr">55</a>]. Copyright © 2016 Elsevier). Full article ">Figure 3
(A) 3D-bioprinted constructs as a function of CMC/alginate hydrogel formulations; (B) comparison of cell viability in alginate and CMC/alginate hydrogels at different times. * Significant differences between alginate and CMC/alginate (p = 0.05); (C) cell-laden scaffold and filament. (Reprinted and adapted from Habib et al., 2018 [<a href="#B60-engproc-81-00003" class="html-bibr">60</a>]. Copyright © 2018 MDPI under the terms and conditions of the Creative Commons Attribution license). Full article ">Figure 4
(A) Photographs of various NFC/gellan gum hydrogel-based inks with different layer counts following crosslinking; (B) micrographs of morphologies of the different freeze-dried printed structures. Red arrows indicate the presence of pores; (C) cell viability of NFC/gellan gum hydrogel-based inks (dotted line: cell viabilities were all well above the 70% cell viability threshold). * Significant differences compared to the control (p < 0.05).(Reprinted and adapted with permission from Lameirinhas et al., 2023 [<a href="#B61-engproc-81-00003" class="html-bibr">61</a>]. Copyright © 2023 Elsevier). Full article ">

9 pages, 549 KiB

Open AccessProceeding Paper

Biological Treatment of Second Cheese Whey Using Marine Microalgae/Cyanobacteria-Based Systems

by Stefania Patsialou, Ioanna Aikaterini Tsakona, Dimitris V. Vayenas and Athanasia G. Tekerlekopoulou

Eng. Proc. 2024, 81(1), 4; https://doi.org/10.3390/engproc2024081004 - 16 Jan 2025

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Abstract

The biological treatment of second cheese whey (SCW) was investigated using two different marine cultures, the microalgae Picochlorum costavermella and the cyanobacterium Geitlerinema sp. Seawater from the coastal area of Rio, near Patras, was used for dilution of the SCW to achieve an [...] Read more.

The biological treatment of second cheese whey (SCW) was investigated using two different marine cultures, the microalgae Picochlorum costavermella and the cyanobacterium Geitlerinema sp. Seawater from the coastal area of Rio, near Patras, was used for dilution of the SCW to achieve an initial concentration of about 2000 mg d-COD/L in both cases without any external additions of the inorganic nutrients N and P. The growth of the mixed biomass, the removal of nutrients and the simultaneous accumulation of bioproducts over time were studied, with d-COD removal reaching 65% and maximum lipid and protein contents, up to 24% and 41.7%, respectively. Full article

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10 pages, 569 KiB

Open AccessProceeding Paper

Hip Injuries in Dancer Athletes Due to Biomechanical Loading: A Systematic Review

by Alexandra Migdou, Athanasios Triantafyllou, Panagiotis Gkrilias, Maria Kyriakidou and Georgios Papagiannis

Eng. Proc. 2024, 81(1), 5; https://doi.org/10.3390/engproc2024081005 - 27 Jan 2025

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Abstract

Professional dancers are susceptible to lower limb pathologies, particularly in the hip joint, due to biomechanical stress. Multiple factors contribute to this, requiring a particular therapeutic approach to address them. This review aims to document these injuries, identify the contributing causes, and propose [...] Read more.

Professional dancers are susceptible to lower limb pathologies, particularly in the hip joint, due to biomechanical stress. Multiple factors contribute to this, requiring a particular therapeutic approach to address them. This review aims to document these injuries, identify the contributing causes, and propose appropriate treatment modalities. This research was conducted by searching the PubMed, ScienceDirect, and Google Scholar databases using relevant keywords and phrases, and in accordance with the PRISMA guidelines. The major findings suggest that the most prevalent conditions include snapping hip syndrome, femoroacetabular impingement syndrome, acetabular labral tears, bursitis, and fatigue fractures. The main factors contributing to these results include excessive joint range of motion, increased training loads, hyperactivity, gender, and BMI. Dancers are susceptible to injuries; nevertheless, studies on this topic are limited, necessitating further research to strengthen their methodological level and establish their results. Full article

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9 pages, 2903 KiB

Open AccessProceeding Paper

Muscle Networks Dynamic in Demanding Postural Tasks and Visual Feedback Privation: A Preliminary Study

by Ana Lía Albarracín, Fernando Daniel Farfán, Leonardo Ariel Cano, Juan D. Romero-Ante, Juan S. Montenegro-Bravo and Eduardo Fernandez-Jover

Eng. Proc. 2024, 81(1), 6; https://doi.org/10.3390/engproc2024081006 - 10 Feb 2025

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Abstract

Postural stability relies on the effective interaction between sensory feedback integration and muscle modulation. This study investigates the dynamics of muscle networks generated during challenging postures and examines the impact of visual feedback deprivation on balance. The postural conditions included three tasks selected [...] Read more.

Postural stability relies on the effective interaction between sensory feedback integration and muscle modulation. This study investigates the dynamics of muscle networks generated during challenging postures and examines the impact of visual feedback deprivation on balance. The postural conditions included three tasks selected from the Berg Balance Scale: standing feet apart, standing feet together, and tandem stance. Additionally, these postures were performed with both open and closed eyes. Electromyographic (EMG) signals were collected bilaterally from six leg and hip muscles. Intermuscular coherence (IMC) was calculated across the twelve muscles within the beta frequency band to identify the muscle networks activated under different postural conditions. The findings revealed a decrease in the number of connections across the sequence of postures, alongside the strengthening of specific muscle connections unique to each individual. These shared patterns and individualized muscle networks may reflect adaptive strategies employed to maintain stability during challenging postural tasks. Full article

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Experimental protocol. (A) Schematic representation of the three postures evaluated and the corresponding base of support. From left to right: standing feet apart (SFA), standing feet together (SFT), and tandem stance (T). (B) EMG electrodes in bipolar configuration were situated over 6 muscles (both sides): tibialis anterior (TA), gastrocnemius medialis (GM), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), and tensor fasciae latae (TFL). Note that GM, BF, and ESP are located at the back of the subjects’ legs. Reference electrodes (ref) were situated over the heel (both sides). Full article ">Figure 2
Equipment and EMG signals. Images of the equipment used for the experimental protocol and an example of the signals obtained. Full article ">Figure 3
Intermuscular coherence procedure. Left and Middle panels: mean auto-spectrum of TFL muscles. Right panel: cross-spectrum and frequency bands delimited. In white: beta frequency band. Full article ">Figure 4
Connectivity matrix obtained for the 3 participants in beta frequency band. The values inside the colored boxes are IMC corresponding to T-EC posture. The colored scale on the right indicates the connectivity strength between two muscles under this postural condition. From left to right: subjects 1 to 3. Full article ">Figure 5
IMC analysis in beta band. Muscle networks generated during different conditions to stabilize the posture. The human figures were standardized in one posture (SFA) to clearly show the connections. SFA: Standing with feet apart. SFT: Standing with feet together. EO: Eyes open. EC: Eyes closed. Thicker and darker lines represent stronger connections and greater number of connections corresponds to larger size of the nodes (circles). Full article ">

7 pages, 5179 KiB

Open AccessProceeding Paper

Optimization of the Spinning Parameters for Wire-Based Electrospinning of Casein–PEO Nanofiber Mats

by Hiram Gyrad Ramirez Candia, Uwe Güth, Timo Grothe and Andrea Ehrmann

Eng. Proc. 2024, 81(1), 7; https://doi.org/10.3390/engproc2024081007 - 14 Feb 2025

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Abstract

Casein is a natural milk protein that has been investigated for various applications. Casein nanofibers are of great interest for tissue engineering. Spinning casein alone has proven difficult due to its unsuitable viscoelasticity and extensive intermolecular interactions. Our study aims at optimizing casein/poly(ethylene [...] Read more.

Casein is a natural milk protein that has been investigated for various applications. Casein nanofibers are of great interest for tissue engineering. Spinning casein alone has proven difficult due to its unsuitable viscoelasticity and extensive intermolecular interactions. Our study aims at optimizing casein/poly(ethylene oxide) (PEO) spinning solutions for needleless electrospinning. For this purpose, PEO with different molecular weights was mixed with different caseins in different ratios and processed with different spinning parameters. Scanning electron microscopy (SEM) images show the impact of these parameters on the diameter distribution and morphology of the nanofibers. The paper gives the first overview of the optimum spinning parameters for wire-based electrospinning of casein/PEO nanofiber mats that are mostly standard values (maximum electrode–electrode distance, carriage speed of 100 mm/s, and PEO with 300 kDa molecular weight), combined with the addition of beeswax to improve fiber morphology and reduce beads. Full article

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7 pages, 1672 KiB

Open AccessProceeding Paper

Bioengineering of Mesenchymal-Stromal-Cell-Based 3D Constructs with Different Cell Organizations

by Natalia Trufanova, Oleh Trufanov, Galyna Bozhok, Ruslana Oberemok, Olena Revenko and Oleksandr Petrenko

Eng. Proc. 2024, 81(1), 8; https://doi.org/10.3390/engproc2024081008 - 17 Feb 2025

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Abstract

Standard 2D cultures inadequately mimic the natural microenvironment of mesenchymal stromal cells (MSCs), compromising their properties. This study investigated the impact of 3D cultures in spheroids, alginate microspheres (AMSs), and blood plasma scaffolds on human-adipose-derived MSC behavior. The cell morphology, viability/apoptosis (6-CFDA/Annexin-Cy3.18), actin [...] Read more.

Standard 2D cultures inadequately mimic the natural microenvironment of mesenchymal stromal cells (MSCs), compromising their properties. This study investigated the impact of 3D cultures in spheroids, alginate microspheres (AMSs), and blood plasma scaffolds on human-adipose-derived MSC behavior. The cell morphology, viability/apoptosis (6-CFDA/Annexin-Cy3.18), actin filament development (phalloidin-FITC), and metabolic activity (Alamar Blue) were assessed on the 3rd day of the generated 3D construct cultures. The abilities for adipogenic and osteogenic differentiation were evaluated after 21 days of culture in media with inducers by Nile Red and Alizarin Red staining, respectively. The 3D culture supported closer-to-physiological cell interactions and morphology and resulted in F-actin reduction compared with the 2D culture. While the metabolic activity was elevated in the scaffolds, it was significantly reduced in the spheroids and AMSs, which reflected natural-like quiescence. The differentiation was maintained across all the 3D constructs. These findings highlight the essential influence of 3D construct design on MSC function, underscoring its potential for advancing both in vitro models and cell-based therapies. Full article

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