Antibacterial and biodegradable properties of polyhydroxyalkanoates grafted with chitosan and chitooligosaccharides via ozone treatment

Acrylic acid was grafted to ozone‐treated poly(3‐hydroxybutyric acid) (PHB) and poly(3‐hydroxybutyric acid‐co‐3‐hydroxyvaleric acid) (PHBV) membranes. The resulting membranes were further grafted with chitosan (CS) or chitooligosaccharide (COS) via esterification. These CS‐ or COS‐grafted membranes showed antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, methicilin‐resistant Staphylococcus aureus (MRSA), and S. aureus. The antibacterial activity to E. coli was the highest, whereas the antibacterial activity to MRSA was the lowest among these four bacteria tested. Acrylic acid grafting can increase the biodegradability with Alcaligens faecalis, whereas CS and COS grafting can reduce the biodegradability. In addition, CS‐grafted PHBV membrane showed higher antibacterial activity and lower biodegradability than COS‐grafted PHBV membrane. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 2797–2803, 2003     

Synthesis of modified poly(ethylene terephthalate) fibers with antibacterial properties and their characterization

Poly(ethylene terephthalate) (PET) fibers were grafted with vinyl monomers by utilizing benzoyl peroxide. Grafted PET fibers were modified in optimized conditions with several functional groups such as amine, chlorine, hydrogen peroxide_, and triclosan to gain antibacterial feature. The second part of this study comprised examination of the antibacterial features of PET fibers via use of Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922) bacteria. Kirby-Bauer test is used to study antibacterial properties. The longest zone diameter for Trc-GMA-g-PET fibers was 56?mm for E. Coli whereas the biggest diameter for S. aureus bacteria was 130?mm with Trc-MMA-g-PET fibers.     

Biocompatibility and antibacterial activity of chitosan and hyaluronic acid immobilized polyester fibers

Poly(ethylene terephthalate) (PET) fibers were treated with ⁶⁰Co‐γ‐ray and grafted with acrylic acid. The resulting fibers were further grafted with chitosan (CS) via esterification. Afterward, hyaluronic acid (HA) was immobilized onto CS‐grafting fibers. The antibacterial activity of CS against S. aureus, E. coli, and P. aeruginosa was preserved after HA‐immobilization. After immobilizing HA, the L929 fibroblasts cell proliferation was improved forCS‐grafting PET fiber. The results indicate that by grafting with CS and immobilizing with HA, PET fibers not only exhibit antibacterial activity, but also improve the cell proliferation for fibroblast. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 220–225, 2007     

Antibacterial functionalization of cotton fabrics by electric‐beam irradiation

An N‐halamine precursor monomer, 2,2,6,6‐tetramethylpiperidinyl acrylate (TMPA), was synthesized and successfully grafted onto cotton fibers via an impregnation process (IP) and electron‐beam irradiation (EB). The grafted cotton fibers could provide antibacterial efficacy after chlorination through a dilute sodium hypochlorite solution. The antibacterial efficacy was challenged against Staphylococcus aureus and Escherichia coli. The cotton fibers grafted with TMPA and acrylic acid by EB inactivated all of the bacteria within 30 min of contact, whereas the samples grafted with TMPA via an IP could not completely kill the bacteria with 60 min. The breaking strength and UVA light stability also improved significantly. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42023.     

Biocompatible surface modification of poly(ethylene terephthalate) focused on pathogenic bacteria: Promising prospects in biomedical applications

Poly(ethylene terephthalate)—PET, is one of the most common polyesters, widely used in biomedical applications ranging from catheters to stents, vascular grafts, heart valves, sutures, and scaffolds. PET surface modification is necessary to impart desired properties for biomedical applications, making the polymer biocompatible, noncytotoxic and antibacterial that can preferably resist biofilm formation caused by pathogenic bacteria. A novel approach to anticorrosive wet chemical surface modification of PET by insertion of alkyl and hydroxyl groups was achieved by using Grignard reagents and confirmed by several different characterization methods including Fourier transform infrared spectroscopy (FTIR), water contact angle (WCA) measurement, free surface energy (FSE) measurement, scanning electron microscopy (SEM), and atomic force microscopy (AFM). High antibacterial efficiency against four different types of biofilm active, pathogenic bacterial strains namely: Staphylococcus aureus, Escherichia coli, methicillin‐resistant S. aureus (MRSA), and Pseudomonas aeruginosa was established on the modified PET surface. Biocompatibility higher than 84% of the modified samples has been proved. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44990.     

Antimicrobial poly(N‐vinyl‐2‐pyrrolidone‐alt‐maleic anhydride)/poly(ethylene imine) macrocomplexes

The antimicrobial polymer/polymer macrocomplexes were synthesized by radical alternating copolymerization of N‐vinyl‐2‐pyrrolidone with maleic anhydride [poly(VP‐alt‐MA)] with 2,2′‐azobis‐isobutyronitrile as an initiator at 65°C in dioxane solutions under nitrogen atmosphere, and interaction of prepared copolymer with poly(ethylene imine) (PEI) in aqueous solutions. The susceptibility of some Gram‐negative (Salmonella enteritidis and Escherichia coli) and Gram‐positive (Staphylococcus aureus and Listeria monocytogenes) bacteria to the alternating copolymer and its PEI macrocomplexes with different compositions in microbiological medium was studied using pour‐plate technique. All the studied polymers, containing biologically active moieties in the form of ionized cyclic amide, and macrobranched aliphatic amine groups and acid/amine complexed fragments, were more effective against L. monocytogenes than those for Gram‐positive S. aureus bacterium. This fact was explained by different surface layer structural architectures of biomacromolecules of tested bacteria. The resulting polymeric antimicrobial materials are expected to be used in various areas of medicine and food industry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5841–5847, 2006     

Preparation and antibacterial activity of PET/chitosan nanofibrous mats using an electrospinning technique

The nanofiber deposition method, by electrospinning, was employed to introduce antibacterial activity and biocompatibility to the surface of poly (ethylene terephthalate) (PET) textiles. The polymer blends of PET and chitosan were electrospun on to the PET micro‐nonwoven mats for biomedical applications. The PET/chitosan nanofibers were evenly deposited on to the surface, and the diameter of the nanofibers was in the range between 500 and 800 nm. The surface of the nanofibers was characterized using SEM, ESCA, AFM, and ATR‐FTIR. The wettability of the PET nanofibers was significantly enhanced by the incorporation of chitosan. The antibacterial activity of the samples was evaluated utilizing the colony counting method against Staphylococcus aureus and Klebsiella pneumoniae. The results indicated that the PET/chitosan nanofiber mats showed a significantly higher growth inhibition rate compared with the PET nanofiber control. In addition, the fibroblast cells adhered better to the PET/chitosan nanofibers than to the PET nanofibers mats, suggesting better tissue compatibility. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Antibacterial activities of novel nanocomposite biofilms of chitosan/phosphoramide/Ag NPs

Novel nanocomposite films of chitosan/phosphoramide/Ag NPs were prepared containing 1–5% of silver nanoparticles. The Ag NPs were synthesized according to the citrate reduction method. The XRD and SEM analysis of Ag NPs, chitosan (CS), phosphoramide (Ph), CS/Ph, CS/Ag NPs films and the nanocomposite films 1–5 containing CS/Ph/1–5% Ag NPs were investigated. The in vitro antibacterial activities were evaluated against four bacteria including two Gram‐positive Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and two Gram‐negative Escherchia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) bacteria. Results revealed greater antibacterial effects of the films against Gram‐positive bacteria. Also, nanocomposite films containing higher percent of Ag NPs showed more antibacterial activities. POLYM. COMPOS. 36:454–466, 2015. © 2014 Society of Plastics Engineers     

Antibacterial activity and cytotoxicity of hydrogel–nanosilver composites based on copolymers from 2‐acrylamido‐2‐methylpropanesulfonate sodium

In this research, we contributed to the search for potential hydrogel–silver dressings by generating hydrogel–silver nanoparticles (AgNPs) composites prepared by the dipping of the crosslinked hydrogel poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium) (1:1) and poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium) (1:1) into an aqueous suspension of citrate‐stabilized AgNPs. The composites obtained were evaluated by an antibacterial activity assay on Staphylococcus aureus and Escherichia coli and subjected to an in vitro cytotoxicity assay for human fibroblasts. The composite formed from the hydrogel poly(N‐vinylpyrrolidone‐co‐2‐acrylamido‐2‐methylpropanesulfonate sodium) with 3 mol % N,N‐methylene bisacrylamide showed the highest antibacterial activity and the least cytotoxicity among the composites tested; this makes it an excellent alternative as a potential dressing for the treatment of deep and exudative wounds. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39644.     

Antibacterial Activity of Poly(aniline-co-ethylaniline) against Staphylococcus aureus and Pseudomonas aeruginosa

This study describes the preparation of colloidal poly(aniline-co-ethylaniline) by chemical copolymerization. The product was characterized morphologically using scanning electron microscope and transmission electron microscopy, chemically using Fourier transform infrared spectroscopy and optically ultraviolet–visible spectroscopy. The prepared polymer was then tested for the antibacterial properties against Gram-negative bacteria; Pseudomonas aeruginosa and Gram-positive bacteria; Staphylococcus aureus. The antibacterial properties were assessed by disk diffusion, minimum inhibitory concentration, minimum bactericidal concentrations, and bactericidal kinetic methods. It was found that the minimum inhibitory concentration and minimum bactericidal concentrations values of poly(aniline-co-ethylaniline) against P. aeruginosa were 0.62 mg/ml and 1.25, respectively. The values of minimum inhibitory concentration and minimum bactericidal concentrations for S. aureus were 0.62 mg/ml.     

Surface modification of electrospun chitosan nanofibrous mats for antibacterial activity

Chitosan (CS) blended with poly(ethylene oxide) (PEO) was electrospun into nanofibrous mats. The spinning solution of 6.7 : 0.3 (% w/v) of CS : PEO was dissolved in a 70 : 30 (v/v) trifluoroacetic acid/dichloromethane solution. The obtained fibers were smooth without beads on their surfaces and average diameter of the fiber was 272 ± 56 nm. N‐(2‐hydroxyl) propyl‐3‐trimethyl ammonium chitosan chloride (HTACC) and N‐benzyl‐N,N‐dimethyl chitosan iodide (QBzCS) were each prepared from the CS/PEO mats. They were identified by Fourier‐transform infrared and X‐ray photoelectron spectroscopy and degree of swelling in water. Both quaternized electrospun chitosan mats exhibited superior antibacterial activity to the unmodified electrospun CS/PEO against Staphylococcus aureus and Escherichia coli at short contact times. After 4 h of contact, the reduction of both bacterial strains by CS/PEO, HTACC, and QBzCS was equal at about 99–100%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40981.     

Dual action bactericides: Quaternary ammonium/N‐halamine‐functionalized cellulose fiber

Bi‐functional antibacterial material was prepared by co‐grafting N‐halamine and quaternary ammonium salt monomers from cellulose fiber. The grafted fiber was characterized by Fourier transform infrared spectra, and X‐ray photoelectron spectra. The N‐halamine derived from the precursor 4‐[(acryloxy)methyl]‐4‐ethyl‐2‐oxazolidinone via chlorination treatment and the oxidative chlorine (Cl⁺) leaching behavior were investigated. The antibacterial activities of singly (only QAs‐functionalized or only Cl⁺‐releasing) and dual (QAs‐functionalized and Cl⁺‐releasing) functional cellulose fibers were tested against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus. Compared to singly functionalized formulations, the bi‐functional cellulose fiber exhibited excellent and rapid bactericidal performance against both E. coli and S. aureus. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40070.     

Synthesis of block copolymers via redox polymerization

Polymerization and copolymerization of vinyl monomers such as acrylamide, acrylonitrile, vinyl acetate, and acrylic acid with a redox system of Ce(IV) and organic reducing agents containing hydroxy groups were studied. The reducing compounds were poly(ethylene glycol)s, halogen‐containing polyols, and depolymerization products of poly(ethylene terephthalate). Copolymers of poly(ethylene glycol)s‐b‐polyacrylonitrile, poly(ethylene glycol)s‐b‐poly(acrylonitrile‐co‐vinyl acetate), poly(ethylene glycol)s‐b‐polyacrylamide, poly(ethylene glycol)s‐b‐poly(acrylamide‐co‐vinyl acetate), poly(1‐chloromethyl ethylene glycol)‐bpoly(acrylonitrile‐co‐vinyl acetate), and bis[poly(ethylene glycol terephthalate)]‐b‐poly(acrylonitrile‐co‐vinyl acetate) were produced. The yield of acrylamide polymerization and the molecular weight of the copolymer increased considerably if about 4% vinyl acetate was added into the acrylamide monomer. However, the molecular weight of the copolymer was decreased when 4% vinyl acetate was added into the acrylonitrile monomer. Physical properties such as solubility, water absorption, resistance to UV light, and viscosities of the copolymers were studied and their possible uses are discussed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1385–1395, 1999     

Research on the preparation and antibacterial properties of 2‐N‐thiosemicarbazide‐6‐O‐hydroxypropyl chitosan membranes with iodine

The 2‐N‐thiosemicarbazide‐6‐O‐hydroxypropyl chitosan (ATU‐HPCS) was prepared by chitosan grafted hydroxypropyl and thiosemicarbazide through the method of “amino protection‐graft‐deprotection,” while the ATU‐HPCS gel membranes were obtained from gelatin and polyvinyl pyrrolidone as additives, and the ATU‐HPCS membranes with iodine (ATU‐HPCS‐I₂‐M) were prepared by adding the ethanol solution of iodine in the ATU‐HPCS gel membranes. The ATU‐HPCS‐I₂‐M were characterized to evaluate their potential applications as antibacterial materials. The iodine releasing rule of ATU‐HPCS‐I₂‐M showed a sustained‐release effect of iodine, the maximum emission was approximately 0.80%. The inhibition zone diameters of ATU‐HPCS‐I₂‐M against Staphylococcus aureus (as Gram‐positive bacteria) and Escherichia coli (as Gram‐negative bacteria) were both greater than 15 mm, it demonstrated significant antibacterial activity compared with the ATU‐HPCS gel membranes. The double effects of the biocompatibility of chitosan and the sustained‐release of iodine provided an ideal healing environment for wound surface. These properties have made ATU‐HPCS‐I₂‐M highly potential as a novel natural macromolecule antimicrobial material preventing the bacteria from burns, surgery wounds, etc. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40535.     

Synthesis,characterization, and antimicrobial activity of silver nanoparticles on poly(GMA‐co‐EGDMA) polymer support

Poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) (poly(GMA‐co‐EGDMA) macroporous copolymer decorated with silver nanoparticles was prepared by a modification of poly(GMA‐co‐EGDMA) in the reaction with arginine, and consequent reduction of silver ions with amino groups. The mercury intrusion porosimetry, transmission electron microscopy, X‐ray diffraction, UV–vis reflection spectroscopy, and inductively coupled plasma atomic emission measurements were used to characterize obtained composite. The coordination of silver nanoparticles to the poly(GMA‐co‐EGDMA) copolymer was studied using infrared spectroscopy. Time dependence and concentration dependence of the antimicrobial efficiency of composite were tested against Gram‐negative bacteria Escherichia coli , Gram‐positive bacteria Staphylococcus aureus , and fungus Candida albicans . The composite ensured maximum reduction of both bacteria, while the fungi reduction reached satisfactory 96.8%. Preliminary antimicrobial efficiency measurements using laboratory flow setup indicated potential applicability of composite for wastewater treatment. POLYM. COMPOS., 38:1206–1214, 2017. © 2015 Society of Plastics Engineers     

Effects of pore morphology and size on antimicrobial activity of chitosan/poly(ethylene glycol) diacrylate macromer semi‐IPN hydrogels

The objective of this study was to obtain antibacterial active chitosan/poly(ethylene glycol) diacrylate macromere (CS/PEGM) semi‐IPN hydrogels near a neutral pH level by changing their pore size and morphology. These hydrogels were prepared from CS and PEGM with different molecular weights in the presence of pore‐forming agents, poly (ethylene glycol) (PEG) or sodium bicarbonate (NaHCO₃), by using two different initiator system, namely chemical or UV. A combination of CS with PEG or NaHCO₃ in the presence of PEGM could be able to create desired pore formation in both initiator systems. The antibacterial activity of hydrogels changed with the molecular weight (g/mol) of PEGM in the order 2000>400>8000. A chemical initiation system was found more suitable than the UV initiation system for antibacterial activity. Hydrogels showing the highest antibacterial activity on Staphylococcus aureus and Escherichia coli have medium or distributed pore size and interconnected pores. Hydrogels prepared with PEGM (M_n: 2000 g/mol) were proposed for antibacterial wound dressing and soft tissue regeneration applications owing to their antibacterial activity and elastic modulus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42707.     

Durable antibacterial finish on cotton fabric by using chitosan‐based polymeric core‐shell particles

Cotton fabric with excellent antibacterial durability was obtained when treated with chitosan‐containing core‐shell particles without any chemical binders. These amphiphilic nanosized particles with antibacterial chitosan shells covalently grafted onto polymer cores were prepared via a surfactant‐free emulsion copolymerization in aqueous chitosan. Herein, two core‐shell particles, one with poly(n‐butyl acrylate) soft core and another with crosslinked poly(N‐isopropylamide) hard core, were synthesized and applied to cotton fabric by a conventional pad‐dry‐cure process. Antimicrobial activity was evaluated quantitatively using a Shake Flask Method in which the reduction of the number of Staphylococcus aureus cells was counted. The results showed that treated fabric had an excellent antibacterial property with bacterial reduction higher than 99%. The antibacterial activity maintained at over 90% reduction level even after 50 times of home laundering. The fabric surface morphology as well as the effect of latex particles with different core flexibilities on fabric hand, air permeability, break tensile strength, and elongation was investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1787–1793, 2006     

Surface grafting polymerization of N‐vinyl‐2‐pyrrolidone onto a poly(ethylene terephthalate) nonwoven by plasma pretreatment and its antibacterial activities

The objective of this research was the surface grafting polymerization of biocompatible monomer N‐vinyl‐2‐pyrrolidone (NVP) onto a plasma‐treated nonwoven poly(ethylene terephthalate) (PET) substrate with ultraviolet (UV)‐induced methods. The effects of various parameters, such as the monomer concentration, reaction time, initiator (ammonium peroxodisulfate) concentration, and crosslinking agent (N,N′‐methylene bisacrylamide) concentration, on the grafting percentage were studied. The grafting efficiency of the modified nonwoven PET surfaces reached a maximum at 50 min of UV irradiation and with a 30 wt % aqueous NVP solution. After the plasma activation and/or grafting, the hydrophobic surface of the nonwoven was modified into a hydrophilic surface. NVP was successfully grafted onto nonwoven PET surfaces. The surface wettability showed that the water absorption of NVP‐grafted nonwoven PET (NVP‐g‐nonwoven PET) increased with increasing grafting time. NVP‐g‐nonwoven PET was verified by Fourier transform infrared spectra and scanning electron microscopy measurements. An antibacterial assessment using an anti‐Staphylococcus aureus test indicated that S. aureus was restrained from growing in NVP‐g‐nonwoven PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 803–809, 2006     

Preparation of chitosan‐g‐poly(acrylamide)/montmorillonite superabsorbent polymer composites: Studies on swelling,thermal, and antibacterial properties

Superabsorbent composites based on chitosan‐g‐poly(acrylamide) and montorillonite (CTS‐g‐PAAm/MMT) were synthesized through in situ radical polymerization by grafting of crosslinked acrylamide onto chitosan backbone in presence of MMT at different contents. The formation of the grafted network was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetery (DSC). The obtained porous structure was observed by scanning electron microscope (SEM). The presence of clay and its interaction with chitosan‐g‐poly(acrylamide) (CTS‐g‐PAAm) matrix was evidenced by ATR‐FTIR analysis. The morphology was investigated by both X‐ray diffraction (XRD) and SEM analyses. It was suggested the formation of mostly exfoliated structures with more porous structures. Besides, the thermal stability of these composites, observed by TGA analysis, was slightly affected by the clay loading as compared to the matrix. These hydrogel composites were also hydrolyzed to achieve anionic hydrogels with ampholytic properties. Swelling behaviors were examined in doubly distilled water, 0.9 wt % NaCl solution and buffer solutions. The water absorbency of all superabsorbent composites was enhanced by adding clay, where the maximum was reached at 5 wt % of MMT. Their hydrolysis has not only greatly optimized their absorption capacity but also improved their swelling rate and salt‐resistant ability. The hydrolyzed superabsorbent showed better pH‐sensitivity than the unhydrolyzed counterparts. The results of the antibacterial activity of these superabsorbents composites against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), assayed by the inhibitory zone tests, have showed moderate inhibition of the bacteria growth. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39747.     

Synthesis of well‐defined responsive membranes with fixable solvent responsiveness

A versatile method is described to synthesize a new family of solvent‐responsive membranes whose response states can be not only tunable but also fixable via ultraviolet (UV) irradiation induced crosslinking. The atom transfer radical polymerization (ATRP) initiator 2‐bromoisobutyryl bromide was first immobilized on the poly(ethylene terephthalate) (PET) track‐etched membrane followed by room‐temperature ATRP grafting of poly(2‐hydroxyethyl methacrylate) (PHEMA) and poly(2‐hydroxyethyl methacrylate‐co‐2‐(dimethylamino)ethyl methacrylate) (P(HEMA‐co‐DMAEMA)) respectively. The hydroxyl groups of PHEMA were further reacted with cinnamoyl chloride (a photosensitive monomer) to obtain photo‐crosslinkable PET‐g‐PHEMA/CA membrane and PET‐g‐P(HEMA/CA‐co‐DMAEMA) membrane. The length of grafted polymer chains was controllable by varying the polymerization time. X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy in attenuated total reflection and thermogravimetric analysis were employed to characterize the resulting membranes. The various membrane surface morphologies resulting from different states of the grafted chains in water and dimethylformamide were characterized by scanning electron microscopy. It was demonstrated that the grafted P(HEMA/CA‐co‐DMAEMA) chains had more pronounced solvent responsivity than the grafted PHEMA/CA chains. The surface morphologies of the grafted membranes could be adjusted using different solvents and fixed by UV irradiation crosslinking. © 2014 Society of Chemical Industry