Polymers

Research

Jump to: Review

13 pages, 2996 KiB

Open AccessArticle

Antimicrobial Properties of Polyaniline and Polypyrrole Decorated with Zinc-Doped Copper Oxide Microparticles

by Moorthy Maruthapandi, Arumugam Saravanan, John H. T. Luong and Aharon Gedanken

Polymers 2020, 12(6), 1286; https://doi.org/10.3390/polym12061286 - 4 Jun 2020

Cited by 45 | Viewed by 5485

Abstract

Polyaniline (PANI) and polypyrrole (PPY) were synthesized by carbon dots (CDs) under UV irradiation and then sonicated together with zinc acetate and copper acetate to form the PANI-Zn@CuO and PPY-Zn@Cu composites. The former consisted of agglomerated spherical particles with diameters of 1–5 µm, [...] Read more.

Polyaniline (PANI) and polypyrrole (PPY) were synthesized by carbon dots (CDs) under UV irradiation and then sonicated together with zinc acetate and copper acetate to form the PANI-Zn@CuO and PPY-Zn@Cu composites. The former consisted of agglomerated spherical particles with diameters of 1–5 µm, whereas the latter displayed irregular stick shapes with similar diameters. The bacterial potency of the composites against Escherichia coli and Staphylococcus aureus was enhanced remarkably with Zn doping in the CuO matrix, designated as Zn_0.11Cu_0.89O, at 0.144 mg/mL. The cell death was mainly attributed to the release of reactive oxygen species (ROS) that would severely damage DNA, proteins, and lipids. Bacteria could adhere to neutral surfaces of the composites by van der Waals attractive forces. The binding event disrupted the native surface charge of bacterial cells to induce cell lysis and result in eventual cell death. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Figure 1

Figure 1
(a,c) FTIR spectrum and (b,d) XRD diffraction patterns of polymers and polymers’ macro-nanocomposites. In <a href="#polymers-12-01286-f001" class="html-fig">Figure 1</a>b, the two highest peaks of Zn@CuO are known as (−1, 1, 1) and (1, 1, 1), followed by (2, 0, 2). The identities of other peaks can be found in Reference [<a href="#B28-polymers-12-01286" class="html-bibr">28</a>]. A very small peak (1, 1, 0) before the (−1, 1, 1) peak has been reported in the literature, e.g., Reference [<a href="#B27-polymers-12-01286" class="html-bibr">27</a>] but only appears as a broad peak in our experimental conditions. Full article ">Figure 2
SEM and EDX images of the polymer composites. Notes: (a,b) SEM of polypyrrole (PPY)-Zn@CuO, polyaniline (PANI)-Zn@CuO; (c,d) EDX of PPY-Zn@CuO, PANI-Zn@CuO. Full article ">Figure 3
Solid-state 13C NMR spectra of PPY-Zn@CuO and PANI-Zn@CuO macro-nanocomposites. Full article ">Figure 4
Zeta potentials of PANI, PANI-Zn@Cu-O, PPY, and PPY-Zn@CuO. Full article ">Figure 5
(a,b) Antimicrobial effects of PANI-Zn@CuO and PPY-Zn@CuO on E. coli and (c,d) antimicrobial effects of PANI-Zn@CuO and PPY-Zn@CuO on S. aureus. The concentration of pure PANI or PPY is 1 mg/mL, the concentration of Zn@CuO is 0.144 mg/mL, and the polymer composite consists of 0.8 mg/mL of PANI or PPY together with 0.144 mg/mL of Zn@CuO. Full article ">Figure 6
Electron paramagnetic resonance (EPR) measurement for (a) PANI-Zn@CuO and (b) PPY-Zn@CuO. Full article ">Scheme 1
The reduction of oxygen to form water by Zn@CuO, which is involved in the release of superoxide anions, hydrogen peroxide, and hydroxyl radicals. Full article ">

15 pages, 1245 KiB

Open AccessArticle

The Synergistic Microbiological Effects of Industrial Produced Packaging Polyethylene Films Incorporated with Zinc Nanoparticles

by Szymon Mania, Mateusz Cieślik, Marcin Konzorski, Paweł Święcikowski, Andrzej Nelson, Adrianna Banach and Robert Tylingo

Polymers 2020, 12(5), 1198; https://doi.org/10.3390/polym12051198 - 25 May 2020

Cited by 19 | Viewed by 4261

Abstract

Zinc compounds in polyolefin films regulate the transmission of UV-VIS radiation, affect mechanical properties and antimicrobial activity. According to hypothesis, the use of zinc- containing masterbatches in polyethylene films (PE) with different chemical nature—hydrophilic zinc oxide (ZO) and hydrophobic zinc stearate (ZS)—can cause [...] Read more.

Zinc compounds in polyolefin films regulate the transmission of UV-VIS radiation, affect mechanical properties and antimicrobial activity. According to hypothesis, the use of zinc- containing masterbatches in polyethylene films (PE) with different chemical nature—hydrophilic zinc oxide (ZO) and hydrophobic zinc stearate (ZS)—can cause a synergistic effect, especially due to their antimicrobial properties. PE films obtained on an industrial scale containing zinc oxide and zinc stearate masterbatches were evaluated for antimicrobial activity against E. coli and S. aureus strains. The morphology of the samples (SEM), composition (EDX), UV barrier and transparency, mechanical properties and global migration level were also determined. SEM micrographs confirmed the good dispersion of zinc additives in the PE matrix. The use of both masterbatches in one material caused a synergistic effect of antimicrobial activity against both bacterial strains. The ZO masterbatch reduced the transparency of films, increased their UV-barrier ability and improved tensile strength, while the ZS masterbatch did not significantly change the tested parameters. The global migration limit was not exceeded for any of the samples. The use of ZO and ZS masterbatch mixtures enables the design of packaging with high microbiological protection with a controlled transmission for UV and VIS radiation. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

14 pages, 4683 KiB

Open AccessArticle

Preparation of Nanocomposite Alginate Fibers Modified with Titanium Dioxide and Zinc Oxide

by Dominik Borkowski, Izabella Krucińska and Zbigniew Draczyński

Polymers 2020, 12(5), 1040; https://doi.org/10.3390/polym12051040 - 2 May 2020

Cited by 19 | Viewed by 3827

Abstract

Active dressings based on natural polymers are becoming increasingly popular on the market. One of such polymers is alginate, which is characterized by biodegradability, resorbability, has no carcinogenic properties, does not have allergenic or hemostatic properties, and has a confirmed lack of toxicity. [...] Read more.

Active dressings based on natural polymers are becoming increasingly popular on the market. One of such polymers is alginate, which is characterized by biodegradability, resorbability, has no carcinogenic properties, does not have allergenic or hemostatic properties, and has a confirmed lack of toxicity. However, this polymer does not show biocidal and biostatic properties, therefore the purpose of this research was to select the appropriate conditions for the production of calcium alginate fibers modified with nano titanium dioxide and nano zinc oxide. It was assumed that the presence of nano metal oxide fillers will give antibacterial properties to formed fibers, which were used to form nonwovens. The following article presents a comparative analysis of nonwovens made of alginate fibers, without nano additives, with nonwovens made of alginate fibers containing in their structure 7% titanium dioxide and nonwovens made of alginate fibers containing 2% ZnO. The selection of the nano additive content was determined by the spinning ability of the developed polymer solutions. Based on the results contained in the article, it was found that the introduction of modifiers in the structure of fibers increases the diameter of the fiber pores, which improves the sorption and retention properties of the obtained fibers, and also gives differentiated antibacterial properties to the obtained nonwovens depending on the type of nano additive used. Greater activity against Escherichia coli, Staphylococcus aureus strains and Aspergillus Niger molds was shown in nonwovens made of 2% ZnO modified fibers compared to nonwovens made from TiO₂ modified fibers. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

13 pages, 2024 KiB

Open AccessArticle

Hemolytic and Antimicrobial Activities of a Series of Cationic Amphiphilic Copolymers Comprised of Same Centered Comonomers with Thiazole Moieties and Polyethylene Glycol Derivatives

by R. Cuervo-Rodríguez, A. Muñoz-Bonilla, F. López-Fabal and M. Fernández-García

Polymers 2020, 12(4), 972; https://doi.org/10.3390/polym12040972 - 22 Apr 2020

Cited by 20 | Viewed by 4106

Abstract

A series of well-defined antimicrobial polymers composed of comonomers bearing thiazole ring (2-(((2-(4-methylthiazol-5-yl)ethoxy)carbonyl)oxy)ethyl methacrylate monomer (MTZ)) and non-hemotoxic poly(ethylene glycol) side chains (poly(ethylene glycol) methyl ether methacrylate (PEGMA)) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. By post-polymerization functionalization strategy, polymers were [...] Read more.

A series of well-defined antimicrobial polymers composed of comonomers bearing thiazole ring (2-(((2-(4-methylthiazol-5-yl)ethoxy)carbonyl)oxy)ethyl methacrylate monomer (MTZ)) and non-hemotoxic poly(ethylene glycol) side chains (poly(ethylene glycol) methyl ether methacrylate (PEGMA)) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. By post-polymerization functionalization strategy, polymers were quaternized with either butyl or octyl iodides to result in cationic amphiphilic copolymers incorporating thiazolium groups, thus with variable hydrophobic/hydrophilic balance associated to the length of the alkylating agent. Likewise, the molar percentage of PEGMA was modulated in the copolymers, also affecting the amphiphilicity. The antimicrobial activities of these cationic polymers were determined against Gram-positive and Gram-negative bacteria and fungi. Minimum inhibitory concentration (MIC) was found to be dependent on both length of the alkyl hydrophobic chain and the content of PEGMA in the copolymers. More hydrophobic octylated copolymers were found to be more effective against all tested microorganisms. The incorporation of non-ionic hydrophilic units, PEGMA, reduces the hydrophobicity of the system and the activity is markedly reduced. This effect is dramatic in the case of butylated copolymers, in which the hydrophobic/hydrophilic balance is highly affected. The hemolytic properties of polymers analyzed against human red blood cells were greatly affected by the hydrophobic/hydrophilic balance of the copolymers and the content of PEGMA, which drastically reduces the hemotoxicity. The copolymers containing longer hydrophobic chain, octyl, are much more hemotoxic than their corresponding butylated copolymers. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
(a) 1H and (b) 13C nuclear magnetic resonance (NMR) spectra of the copolymer with a PEGMA/MTZ ratio of 50/50. Full article ">Figure 2
Gel permeation chromatography (GPC) curves of the P(PEGMA–co–MTZ) copolymers synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization with different monomer molar ratios PEGMA/MTZ: 100/0, 75/25, 50/50, 25/75, and 0/100 in the feed. Full article ">Figure 3
1H NMR spectrum of the copolymer quaternized with 1-iodobutane, P(PEGMA–co–MTZ-BuI), for a PEGMA/MTZ ratio of 50/50. Full article ">Figure 4
Hemotoxicity behavior of copolymers against red blood cells. Full article ">Scheme 1
Reversible addition-fragmentation chain transfer (RAFT) copolymerization reaction of 2-(((2-(4-methylthiazol-5-yl)ethoxy)carbonyl)oxy)ethyl methacrylate monomer (MTZ) and poly(ethylene glycol) methyl ether methacrylate (PEGMA): preparation of P(PEGMA–co–MTZ) copolymers. CPB, 2-cyano-2-propyl benzodithioate; AIBN, 2,2’-Azobisisobutyronitrile. Full article ">Scheme 2
Quaternization reaction to prepare P(PEGMA–co–MTZ-BuI) and P(PEGMA–co–MTZ-OcI) cationic copolymers. DMF, N,N-dimethylformamide. Full article ">

16 pages, 2327 KiB

Open AccessArticle

Development and Characterization of Hemicellulose-Based Films for Antibacterial Wound-Dressing Application

by Naveed Ahmad, Danial Tayyeb, Imran Ali, Nabil K. Alruwaili, Waqas Ahmad, Atta ur Rehman, Abdul Haleem Khan and Mohammad Saeed Iqbal

Polymers 2020, 12(3), 548; https://doi.org/10.3390/polym12030548 - 3 Mar 2020

Cited by 46 | Viewed by 7294

Abstract

Hemicelluloses are biopolymers with versatile properties for biomedical applications. Herein, hemicellulose (arabinoxylan)-based antibacterial film dressings were prepared and characterized. Arabinoxylan was isolated from psyllium husk. Blank and gentamicin-loaded films were prepared by the solvent cast method using glycerol as the plasticizer. The appropriate [...] Read more.

Hemicelluloses are biopolymers with versatile properties for biomedical applications. Herein, hemicellulose (arabinoxylan)-based antibacterial film dressings were prepared and characterized. Arabinoxylan was isolated from psyllium husk. Blank and gentamicin-loaded films were prepared by the solvent cast method using glycerol as the plasticizer. The appropriate composition of the films was obtained by varying the amounts of arabinoxylan, glycerol, and gentamicin. The films were found to be transparent, smooth, bubble-free, flexible, and easily peelable with 2% to 3% arabinoxylan. They had uniform thickness and swelled up to 60% of their initial size. The mechanical properties and water vapor transmission rate through the films were found to be suitable for wound-dressing application. Fourier transform infrared spectroscopy (FTIR) analysis confirmed drug–film compatibility. In an in vitro release study, more than 85% of the gentamicin was released from the films in 12 h. The antibacterial activities of the gentamicin-loaded films were found to be close to the standard gentamicin solution. The films were found to be cytocompatible in cell viability assay. These results suggested that hemicellulose-based films are promising materials for the dressing of infected wounds. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
Swelling of the AX films (a) swelling index (mean ± SD, n = 3), the asterisks (*) show the significant difference among all three AX films and the hashes (#) show the significant difference of AXF2.5 from AXF3 and AXF2, (b) images films after 5 h of swelling. Full article ">Figure 2
Fourier transform infrared (FTIR) spectra of arabinoxylan (AX), gentamicin (GM), glycerol, blank film (AXF2.5), and GM-loaded film (AXDF2.5). Full article ">Figure 3
Thermal analysis of AX, blank films, and GM-loaded films, (a) thermogravimetric analyses (TGA) and (b) differential scanning calorimetry (DSC). Full article ">Figure 4
SEM micrographs of (a) AXF2.5, (b) AXFD2.5, (c) AXF3, and (d) AXFD3 at 500× magnification. Full article ">Figure 5
In vitro GM release profile of AX-based films (mean ± SD, n = 3). The asterisks (*) indicate significant differences. Full article ">Figure 6
Antibacterial activity of films against (a) S. aureus, (b) E. coli, and (c) P. aeruginosa. Full article ">Figure 7
Effect of blank and GM-loaded films on viability BHK-21 cells (mean ± SD, n = 6). Full article ">

15 pages, 2918 KiB

Open AccessEditor’s ChoiceArticle

Beeswax-Modified Textiles: Method of Preparation and Assessment of Antimicrobial Properties

by Justyna Szulc, Waldemar Machnowski, Stanisława Kowalska, Anita Jachowicz, Tomasz Ruman, Aleksandra Steglińska and Beata Gutarowska

Polymers 2020, 12(2), 344; https://doi.org/10.3390/polym12020344 - 5 Feb 2020

Cited by 28 | Viewed by 9874

Abstract

In this work, beeswax was used for the first time for finishing polyester/Cotton/Viscose blend fabric and polyester fabric. The aims of the study were: (1) to characterize the composition of beeswax (using Gas Chromatography Mass Spectrometry, GC-MS and ¹⁰⁹AgNPET laser desorption/ionization mass [...] Read more.

In this work, beeswax was used for the first time for finishing polyester/Cotton/Viscose blend fabric and polyester fabric. The aims of the study were: (1) to characterize the composition of beeswax (using Gas Chromatography Mass Spectrometry, GC-MS and ¹⁰⁹AgNPET laser desorption/ionization mass spectrometry (LDI MS); (2) to develop a laboratory method for applying beeswax; (3) to assess the antimicrobial activity of beeswax fabrics against bacteria and fungi (AATCC 100–2004 test); and (4) to assess the properties of textiles modified by beeswax. Beeswax was composed of fatty acids, monoacyl esters, glyceride esters and more complex lipids. The bioactivity of modified fabrics was from −0.09 to 1.55. The highest biocidal activity (>1) was obtained for both fabrics against A. niger mold. The beeswax modification process neither affected the morphological structure of the fibers (the wax evenly covered the surface of the fibers) nor their color. The only statistically significant changes observed were in the mechanical properties of the fabrics. The results obtained indicate that modification of fabrics with beeswax may endow them with biocidal properties against molds, which has practical applications, for example, for the prevention of skin mycoses in health and social care facilities. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Figure 1

Figure 1
Scanning electron microscope (SEM) images of cotton fibers surface before and after fabric modification (magnification 2000×); (a)—Control sample (before modification); (b)—After impregnation with beeswax suspension and drying at room temperature; (c)—Sample b after heat treatment at 120 °C for 1 min. Full article ">Figure 2
SEM images of polyester fibers surface before and after fabric modification (magnification 1000×); (a)—Control sample (before modification); (b)—After impregnation with beeswax suspension and drying at room temperature; (c)—Sample b after heat treatment at 120 °C for 1 min. Full article ">Figure 3
SEM images of viscose fibers surface before and after fabric modification (magnification 2000×); (a)—Control sample (before modification); (b)—After impregnation with beeswax suspension and drying at room temperature; (c)—sample B after heat treatment at 120 °C for 1 min. Full article ">Figure 4
Number of microorganisms on Fabric 1; *—Statistically significant differences between number of microorganisms on control and beeswax-modified samples in the same time (one-way ANOVA, p < 0.05). Full article ">Figure 5
Number of microorganisms on Fabric 2. *—Statistically significant differences between number of microorganisms on control and beeswax-modified samples in the same time (one-way ANOVA, p < 0.05). Full article ">

21 pages, 4019 KiB

Open AccessArticle

Durable Antimicrobial Behaviour from Silver-Graphene Coated Medical Textile Composites

by Nuruzzaman Noor, Suhas Mutalik, Muhammad Waseem Younas, Cheuk Ying Chan, Suman Thakur, Faming Wang, Mian Zhi Yao, Qianqian Mou and Polly Hang-mei Leung

Polymers 2019, 11(12), 2000; https://doi.org/10.3390/polym11122000 - 3 Dec 2019

Cited by 34 | Viewed by 6105

Abstract

Silver nanoparticle (AgNP) and AgNP/reduced graphene oxide (rGO) nanocomposite impregnated medical grade polyviscose textile pads were formed using a facile, surface-mediated wet chemical solution-dipping process, without further annealing. Surfaces were sequentially treated in situ with a sodium borohydride (NaBH₄) reducing agent, [...] Read more.

Silver nanoparticle (AgNP) and AgNP/reduced graphene oxide (rGO) nanocomposite impregnated medical grade polyviscose textile pads were formed using a facile, surface-mediated wet chemical solution-dipping process, without further annealing. Surfaces were sequentially treated in situ with a sodium borohydride (NaBH₄) reducing agent, prior to formation, deposition, and fixation of Ag nanostructures and/or rGO nanosheets throughout porous non-woven (i.e., randomly interwoven) fibrous scaffolds. There was no need for stabilising agent use. The surface morphology of the treated fabrics and the reaction mechanism were characterised by Fourier transform infrared (FTIR) spectra, ultraviolet-visible (UV–Vis) absorption spectra, X-ray diffraction (XRD), Raman spectroscopy, dynamic light scattering (DLS) energy-dispersive X-ray analysis (EDS), and scanning electron microscopic (SEM). XRD and EDS confirmed the presence of pure-phase metallic silver. Variation of reducing agent concentration allowed control over characteristic plasmon absorption of AgNP while SEM imaging, EDS, and DLS confirmed the presence of and dispersion of Ag particles, with smaller agglomerates existing with concurrent rGO use, which also coincided with enhanced AgNP loading. The composites demonstrated potent antimicrobial activity against the clinically relevant gram-negative Escherichia coli (a key causative bacterial agent of healthcare-associated infections; HAIs). The best antibacterial rate achieved for treated substrates was 100% with only a slight decrease (to 90.1%) after 12 equivalent laundering cycles of standard washing. Investigation of silver ion release behaviours through inductively coupled plasmon optical emission spectroscopy (ICP-OES) and laundering durability tests showed that AgNP adhesion was aided by the presence of the rGO host matrix allowing for robust immobilisation of silver nanostructures with relatively high stability, which offered a rapid, convenient, scalable route to conformal NP–decorated and nanocomposite soft matter coatings. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
(a) SEM images of for nanocomposite-incorporated polyviscose fibers, both (i) before laundering, and (ii) after laundering, (b) Dark-field optical microscope images of nanocomposite-incorporated polyviscose fibers with longitudinal microscopy images inset. Full article ">Figure 2
(a) XRD patterns of blank substrates, AgNP-, rGO-, and Ag-rGO-impregnated polyviscose non-woven fabrics, at surface treatment NaBH4(aq) reduces the agent concentration of 200 mmol, which confirms the sole presence of fcc metallic silver. (b) EDS of fabric composites highlighting the variation in silver loading between Ag-impregnated and Ag-rGO impregnated non-woven polyviscose substrates, and (c) leaching of silver from Ag/rGO/Ag-rGO-impregnated polyviscose non-woven fabric into 0.85% saline solution at RTP, determined by ICP-OES, measured over 3 h. DL: “Detection limit.” Full article ">Figure 3
UV–Vis absorption spectra for blank substrates, AgNP-impregnated, rGO-impregnated, and Ag-rGO-impregnated polyviscose non-woven fabrics, at surface treatment NaBH4(aq) reducing agent concentrations of 200 mmol, both (a) before, and (b) after, laundering durability testing, indicating the surface plasmon resonance (SPR) band where plasmonic AgNP are present. Full article ">Figure 4
Collated Raman (a) and ATR-FTIR (b) spectra of (i) AgNP, (ii) rGO, and (iii) Ag-rGO-impregnated polyviscose non-woven fabric, at a surface treatment NaBH4(aq) reducing agent concentration of 200 mmol, acquired under ambient conditions, both before and after laundering durability testing (i.e., post-wash (PW)). Full article ">Figure 5
A comparison of viable E. coli counts after 6 h of treatment in the dark at 37 °C on modified composite non-woven polyviscose fabrics, both before and after laundering durability testing (i.e., post-wash (PW)). Full article ">

Review

Jump to: Research

28 pages, 3448 KiB

Open AccessReview

Nanoparticles of Quaternary Ammonium Polyethylenimine Derivatives for Application in Dental Materials

by Marta Chrószcz and Izabela Barszczewska-Rybarek

Polymers 2020, 12(11), 2551; https://doi.org/10.3390/polym12112551 - 30 Oct 2020

Cited by 35 | Viewed by 4853

Abstract

Various quaternary ammonium polyethylenimine (QA-PEI) derivatives have been synthesized in order to obtain nanoparticles. Due to their antibacterial activity and non-toxicity towards mammalian cells, the QA-PEI nanoparticles have been tested extensively regarding potential applications as biocidal additives in various dental composite materials. Their [...] Read more.

Various quaternary ammonium polyethylenimine (QA-PEI) derivatives have been synthesized in order to obtain nanoparticles. Due to their antibacterial activity and non-toxicity towards mammalian cells, the QA-PEI nanoparticles have been tested extensively regarding potential applications as biocidal additives in various dental composite materials. Their impact has been examined mostly for dimethacrylate-based restorative materials; however, dental cements, root canal pastes, and orthodontic adhesives have also been tested. Results of those studies showed that the addition of small quantities of QA-PEI nanoparticles, from 0.5 to 2 wt.%, led to efficient and long-lasting antibacterial effects. However, it was also discovered that the intensity of the biocidal activity strongly depended on several chemical factors, including the degree of crosslinking, length of alkyl telomeric chains, degree of N-alkylation, degree of N-methylation, counterion type, and pH. Importantly, the presence of QA-PEI nanoparticles in the studied dental composites did not negatively impact the degree of conversion in the composite matrix, nor its mechanical properties. In this review, we summarized these features and functions in order to present QA-PEI nanoparticles as modern and promising additives for dental materials that can impart unique antibacterial characteristics without deteriorating the products’ structures or mechanical properties. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

14 pages, 6262 KiB

Open AccessReview

Polymeric Coatings with Antimicrobial Activity: A Short Review

by Ana C. Pinho and Ana P. Piedade

Polymers 2020, 12(11), 2469; https://doi.org/10.3390/polym12112469 - 24 Oct 2020

Cited by 29 | Viewed by 4172

Abstract

The actual situation of microorganisms resistant to antibiotics and pandemics caused by a virus makes research in the area of antimicrobial and antiviral materials and surfaces more urgent than ever. Several strategies can be pursued to attain such properties using different classes of [...] Read more.

The actual situation of microorganisms resistant to antibiotics and pandemics caused by a virus makes research in the area of antimicrobial and antiviral materials and surfaces more urgent than ever. Several strategies can be pursued to attain such properties using different classes of materials. This review focuses on polymeric materials that are applied as coatings onto pre-existing components/parts mainly to inhibit microbial activity, but polymer surfaces with biocidal properties can be reported. Among the several approaches that can be done when addressing polymeric coatings, this review will be divided in two: antimicrobial activities due to the topographic cues, and one based on the chemistry of the surface. Some future perspectives on this topic will be given together with the conclusions of the literature survey. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

47 pages, 10107 KiB

Open AccessReview

Positively Charged Polymers as Promising Devices against Multidrug Resistant Gram-Negative Bacteria: A Review

by Silvana Alfei and Anna Maria Schito

Polymers 2020, 12(5), 1195; https://doi.org/10.3390/polym12051195 - 23 May 2020

Cited by 100 | Viewed by 8722

Abstract

Antibiotic resistance has increased markedly in Gram-negative bacteria, causing severe infections intractable with traditional drugs and amplifying mortality and healthcare costs. Consequently, to find novel antimicrobial compounds, active on multidrug resistant bacteria, is mandatory. In this regard, cationic antimicrobial peptides (CAMPs)—able to kill [...] Read more.

Antibiotic resistance has increased markedly in Gram-negative bacteria, causing severe infections intractable with traditional drugs and amplifying mortality and healthcare costs. Consequently, to find novel antimicrobial compounds, active on multidrug resistant bacteria, is mandatory. In this regard, cationic antimicrobial peptides (CAMPs)—able to kill pathogens on contact—could represent an appealing solution. However, low selectivity, hemolytic toxicity and cost of manufacturing, hamper their massive clinical application. In the recent years—starting from CAMPs as template molecules—less toxic and lower-cost synthetic mimics of CAMPs, including cationic peptides, polymers and dendrimers, have been developed. Although the pending issue of hemolytic toxicity and biodegradability is still left not completely solved, cationic antimicrobial polymers (CAPs), compared to small drug molecules, thanks to their high molecular weight, own appreciable selectivity, reduced toxicity toward eukaryotic cells, more long-term activity, stability and non-volatility. With this background, an updated overview concerning the main manufactured types of CAPs, active on Gram-negative bacteria, is herein reported, including synthetic procedure and action’s mechanism. Information about their structures, antibacterial activity, advantages and drawbacks, was reported in the form of tables, which allow faster consultation and quicker learning concerning current CAPs state of the art, in order not to retrace reviews already available. Full article

(This article belongs to the Special Issue Current Trends in Antimicrobial Polymeric Materials)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Current Trends in Antimicrobial Polymeric Materials

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (10 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI