MGF-Ct24E-modified piperazine polymer: A balance of antimicrobial activity and cytotoxicity

A piperazine oligomer (PE) has been successfully synthesized via green and facile conditions. To obtain equivalent or better antimicrobial activity and smaller cytotoxicity, a mechano-growth factor and its 24-amino acid peptide analog corresponding to the unique C-terminal E-domain (MGF-Ct24E) was introduced to the side chain of PE. Fourier transform infrared spectrometry (FTIR), elemental analysis, and amino acid analyzer (AAA) measurements showed that the MGF-Ct24E-modified piperazine polymer (PEM) was successfully prepared. The antibacterial activity and cytotoxicity of PEM were further investigated. Introduction of MGF-Ct24E resulted in equivalent or improved antibacterial properties and reduced cytotoxicity compared to PE. The resulting material may replenish the current arsenal of synthetic polymeric antibacterial systems reported. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47773.     

Chemical Synthesis and Characterization of Novel Antibacterial Polycyclic Polymer

Polyaniline (PAn) and poly(alkyl substituted anilines) were synthesized in aqueous media by chemical polymerization of alkyl substituted aniline in presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, and mechanism of polymerization with scanning electron microscope (SEM), transmission electron microscopy (TEM), fourier transform infrared (FTIR), and UV–visible spectroscopy (UV–vis), respectively. Results indicated that physicochemical properties of poly(alkyl substituted anilines) depend on substituent groups bonded to N-position. In general, alkyl-substituted PAn have similar chemical and optical properties to parent PAn and it seems that the substituted PAn follow the same polymerization mechanism as reported for PAn. The prepared polymers were then tested for the antibacterial properties against Gram-negative bacteria: Escherichia coli (E. coli). The antibacterial properties were assessed by measuring the zones of inhibition. The antimicrobial results showed clearly that PAn and poly(alkyl substituted anilines) exhibited excellent antibacterial activity against the growth of E. coli microorganism.     

A study of pyridinium‐type functional polymers. IV. Behavioral features of the antibacterial activity of insoluble pyridinium‐type polymers

The antibacterial activity of insoluble pyridinium‐type polymers with different structures against Escherichia coli suspended in sterilized and distilled water was investigated by a colony count method. The results show that the antibacterial activity of insoluble pyridinium‐type polymers, except for one containing I⁻, is characterized by an ability to capture bacterial cells in a living state by adsorption or adhesion, with the process of capturing bacterial cells being at least partially irreversible. This feature differs from the antibacterial activity of the corresponding soluble polymers, which is characterized by the ability to kill bacterial cells in water. In addition, insoluble pyridinium‐type polymers can also capture dead bacterial cells. This implies that insoluble pyridinium‐type polymers possess broad prospects for development in new water treatment techniques and whole‐cell immobilization techniques. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 676–684, 2000     

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     

Preparation and antimicrobial activity of Konjac Glucomannan modified with quaternary ammonium compound

Seven kind of graft copolymerization Konjac Glucomannan with quaternary ammonium group have been prepared, using Konjac Glucomannan (KGM) and methacryloxylethyl alkyl dimethyl ammonium bromide with c₈–c₁₈ alkyl and benzyl in water, ceric ammonium nitrate as initiator, the reaction temperature of 348 K, and the reaction period of 3 h. The structures were confirmed by FTIR. The 15 min inhibitory rates of all the graft copolymerization KGM against Escherichia coli and Staphylococcus aureus reached 99.99%, against Candida albicans somewhat lower, but 30 min inhibitory rate still reached 99.02% for graft copolymerization KGM with quaternary ammonium group having 14 alkyl. The antibacterial mechanism of the graft copolymerization KGM has been investigated by adsorption ability to E. coli, measure of 260 nm absorbing materials and SEM micrographs. Firstly, the bacteria were fastly adsorbed by graft copolymerization KGM. Interactions between bacterial membranes and antibacterial product cause fundamental changes in both membrane structure and function, induced leakage of cytoplasmic contents is a classic indication of damage to the bacterial cytoplasmic membrane. The loss of the connection between the outer membrane and the underlying peptidoglycan induces the abnormality of nodular structures and bleb formation of the cell envelope of E. coli. The antibacterial mechanism is in accordance with microbiologic findings identifying surface blebbing as the first morphologic change occurring in the permeability barrier of gram‐negative bacteria under mild heat stress and laser irradiation, etc. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Facile Fabrication of Povidone Iodine-Embedded Polytetrafluoroethylene Superhydrophobic Films with Improved Antiadhesive and Bactericidal Properties in Bacterial Environments

It remains a challenge to maintain the antiadhesion properties of superhydrophobic films after exposure to bacterial environments. In this work, superhydrophobic bactericidal polymer films via the simple incorporation of polyvinylpyrrolidone-iodine (PVP-I) or iodine into polytetrafluoroethylene (PTFE) are fabricated to improve their antiadhesive and antibacterial capability. Superhydrophobic iodine-embedded films, polytetrafluoroethylene/polyvinylpyrrolidone-iodine and polytetrafluoroethylene-iodine (PTFE/PVP-I and PTFE-I), show excellent antiadhesive and bactericidal performances even post exposure to bacterial solutions as compared to iodine-free counterparts by controlling the release of iodine. Especially, superhydrophobic PTFE/PVP-I films display a more sustained iodine release profile and significant antibacterial properties against gram-positive (S. aureus, methicillin-resistant S. aureus (MRSA)) and gram-negative (E. coli) bacteria. Such a facile combination of antiseptic agents and superhydrophobic surface could be widely used for antiseptic biomedical applications.     

Evaluation of Antibacterial Activity of Nanostructured Copolymers of Poly (Naphthylamine)

The present preliminary investigation highlights for the first time the antibacterial activity of copolymers of nanostructured poly (naphthylamine) (PNA) with aniline (PNA-co-PANI) and o-toluidine (PNA-co-POT) against E. coli and S. aureus. The antibacterial effect of these nanosized polymers was found to be much higher than that reported for pristine polyaniline. The chemical structure and morphology of the copolymers was found to play a significant role in deciding the antimicrobial efficiency of the copolymers. A proposed mechanism of antimicrobial effect has also been suggested. Our results indicate that the antimicrobial effects of the copolymers could be useful ingredients for biomaterials used in the development of food packaging and medical devices.     

Synthesis of polysiloxane with 5,5‐dimethylhydantoin‐based N‐halamine pendants for biocidal functionalization of polyethylene by supercritical impregnation

An N‐halamine precursor 3‐(3‐hydroxypropyl)‐5,5‐dimethylhydantoin (HPDMH) has been synthesized. The N‐halamine precursor was reacted with poly(methylhydrosiloxane) (PMHS) to produce a biocidal polysiloxane with 5,5‐dimethylhydantoin‐based N‐halamine pendants through silane alcoholysis and subsequent chlorination of hydantoin ring with tert‐butyl hypochlorite. The N‐halamine polysiloxane was impregnated into inert polyethylene (PE) fibers and formed a 68‐nm coating layer in supercritical carbon dioxide (scCO₂) for antibacterial application. The PE fibers before and after impregnation were characterized by XPS and SEM. The N‐halamine polysiloxane impregnated PE samples provided effective biocidal activities against both Staphylococcus aureus and Escherichia coli compared with unmodified ones that did not display obvious antibacterial activities. The coating layer on PE substrate was stable toward washing cycles, storage, and UV irradiation and the rechargeability of lost active chlorines was good. The scCO₂ impregnation approach uses environmentally friendly CO₂ as solvent and can be applied to both reactive and nonreactive substrates since it does not require covalent bonds to tether biocidal moieties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44721.     

Synthesis of sulfated β‐cyclodextrin/cotton/ZnO nano composite for improve the antibacterial activity and dyeability with Azadirachta indica

The sulfated β‐cyclodextrin (sb‐cd) was prepared from β‐cyclodextrin and the sb‐cd was crosslinked with cotton fabric using ethylenediaminetetraacetic acid (EDTA) as crosslinker. After crosslinking, the synthesized ZnO nanoparticles were padded on this fabric surface. Then, the treated fabrics were dyed with neem extract. The synthesized polymer, crosslinked and nanoparticle‐treated cotton fabrics were characterized using fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), particle sized analyzer, and transmission electron microscopy (TEM) studies. The antibacterial test was done against Staphylococcus aureus and Escherichia coli bacterium. The composite coated with neem dyed cotton fabric has exhibited 71% of dye uptake with 2–3 fastness grade and it has 99% of antibacterial efficiency for S. aureus and 97% for E. coli bacterium. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Design,Synthesis, and Dual Evaluation of Quinoline and Quinolinium Iodide Salt Derivatives as Potential Anticancer and Antibacterial Agents

A series of novel quinoline and quinolinium iodide derivatives were designed and synthesized to discover potential anticancer and antibacterial agents. With regard to anticancer properties, in vitro cytotoxicities against three human cancer cell lines (A-549, HeLa and SGC-7901) were evaluated. The antibacterial properties against two strains, Escherichia coli (ATCC 29213) and Staphylococcus aureus (ATCC 8739), along with minimum inhibitory concentration (MIC) values were evaluated. The target alkyliodine substituted compounds exhibited significant antitumor and antibacterial activity, of which compound 8-((4-(benzyloxy)phenyl)amino)-7-(ethoxycarbonyl)-5-propyl-[1,3]dioxolo[4,5-g]quinolin-5-ium ( 12 ) was found to be the most potent derivative with IC₅₀ values of 4.45±0.88, 4.74±0.42, 14.54±1.96, and 32.12±3.66 against A-549, HeLa, SGC-7901, and L-02 cells, respectively, stronger than the positive controls 5-FU and MTX. Furthermore, compound 12 had the most potent bacterial inhibitory activity. The MIC of this compound against both E. coli and S. aureus was 3.125 nmol ⋅ mL⁻¹, which was smaller than that against the reference agents amoxicillin and ciprofloxacin.     

Removal of bacteria from water by systems based on insoluble polystyrene–polyethyelnimine

A study was made of the removal of viable bacterial cells from sterilized physiological saline (saline) by insoluble polymer beads. The polymers (CMPS–PEI300 and CMPS–PEI600) were prepared by reactions of chloromethylated, divinylbenzene crosslinked polystyrene (CMPS) beads with polyethyleneimines (PEI) (MW = about 300 and 600). The bacterial strain cells used were Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). Decrease coefficients (D, which corresponds to adsorption rate constant) for the viable cell numbers of E. coli by CPMS–PEI300 and CMPS–PEI600 were 28 and 120 (mL/gh) in saline, respectively. These D's were less than those (72 and 270 mL/gh) in sterilized, distilled, and deionized water (sterilized water). The D's for S. aureus and P. aeruginosa by CMPS–PEI600 were 46 and 76 (mL/g h), respectively. The D for E. coli by CMPS–PEI600 was compared with R (removal coefficient) for that by pyridinium type polymers. Bactericidal activity of PEI600 was examined on E. coli and P. aeruginosa in saline. Also, that of poly(ethylene glycol) 600 was done on E. coli in saline.     

A Novel Strategy for Creating an Antibacterial Surface Using a Highly Efficient Electrospray-Based Method for Silica Deposition

Adhesion of bacteria on biomedical implant surfaces is a prerequisite for biofilm formation, which may increase the chances of infection and chronic inflammation. In this study, we employed a novel electrospray-based technique to develop an antibacterial surface by efficiently depositing silica homogeneously onto polyethylene terephthalate (PET) film to achieve hydrophobic and anti-adhesive properties. We evaluated its potential application in inhibiting bacterial adhesion using both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria. These silica-deposited PET surfaces could provide hydrophobic surfaces with a water contact angle greater than 120° as well as increased surface roughness (root mean square roughness value of 82.50 ± 16.22 nm and average roughness value of 65.15 ± 15.26 nm) that could significantly reduce bacterial adhesion by approximately 66.30% and 64.09% for E. coli and S. aureus, respectively, compared with those on plain PET surfaces. Furthermore, we observed that silica-deposited PET surfaces showed no detrimental effects on cell viability in human dermal fibroblasts, as confirmed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide and live/dead assays. Taken together, such approaches that are easy to synthesize, cost effective, and efficient, and could provide innovative strategies for preventing bacterial adhesion on biomedical implant surfaces in the clinical setting.     

Preparation of antibacterial poly(sulfobetaine methacrylate) grafted on poly(vinyl alcohol)-formaldehyde sponges and their properties

Conventional wound dressings cover wound surfaces and separate them from the outer environment. However, wound sites are readily infected by some bacteria during healing. To overcome these problems, a macroporous sample is designed through the grafting polymerization of hydrophilic sulfobetaine methacrylate (SBMA) on poly(vinyl alcohol)-formaldehyde (PVF) sponges. The as-prepared PVF sponges have a grafting percentage of 15–50%, an average pore size of 60–90 μm, and a high porosity of 90%. This series of PVF-g-PSBMA sponges can absorb deionized water and saline solution at approximately 16 g·g⁻¹ within 2 min because of their hydrophilic surface and macroporous structure. The antibacterial potential of PVF-g-PSBMA sponges against Escherichia coli and Staphylococcus aureus is evaluated via a shake flask test. As the grafting percentage increase from 15 to 50%, the antibacterial activities against Gram-positive S. aureus and Gram-negative E. coli gradually increase from 87 to 95% and from 94 to 99%, respectively. The biocompatibility of these sponges is confirmed through an in vitro cell viability assay. All of the survival rates of the bacterial cells relative to the control (100% of metabolic activity) exceed 90% as the extract ratio of PVF-g-PSBMA sponges increase. Thus, the as-prepared PVF-g-PSBMA sponges can be an ideal wound dressing candidate. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47047.     

Inspired dual functional adsorption films of armed molecules on copper

In this study, double norfloxacin skeletons including the target armed molecules (DNs) displaying antibacterial and anticorrosion properties for copper in aqueous solutions were presented. The molecular modelling and material simulation calculations suggest that the target molecules could be adsorbed to copper surface, which was further demonstrated by attenuated total reflection infrared spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The experimental results show that the copper surface which adsorbed the target armed molecules exhibited an excellent inhibitory effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The potentiodynamic polarization plots and electrochemical impedance spectroscopy demonstrate that the DNs of 0.100 mM achieved over 95% corrosion inhibition efficiency for copper in 0.5 M H₂SO₄ solution at 298 K. The results given in this study may guide us to achieve bacterial and corrosion resistances for copper based on the drug-included armed molecules.     

Liquid-Phase Exfoliation and Functionalization of MoS2 Nanosheets for Effective Antibacterial Application

A lysozyme (Lys)-assisted liquid-phase exfoliation technique was designed to synthesize MoS₂ nanosheets (MoS₂-Lys NSs). As a novel nanozyme antibacterial agent with high peroxidase-like catalyst activity, MoS₂-Lys NSs showed good antibacterial efficacy against both Gram-negative ampicillin-resistant Escherichia coli (Amp^r E. coli) and Gram-positive Bacillus subtilis. A possible antibacterial mechanism is also proposed. This work provides an effective antibacterial strategy based on the MoS₂-Lys NSs antibacterial agent.     

Adsorption and antibacterial effect of copper-exchanged montmorillonite on Escherichia coli K88

Calcium montmorillonite (Ca-MMT), sodium montmorillonite (Na-MMT) and acid-activated montmorillonite (AAM), and their Cu²⁺-exchanged montmorillonites (Cu-MMT), Cu*Ca-MMT, Cu*Na-MMT and Cu*AAM, were used to study the antibacterial activity on Escherichia coli K₈₈. AAM, Na-MMT and Ca-MMT showed some ability to reduce bacterial plate counts by 37.4%, 13.4% and 14.2%, respectively. Exchanging the montmorillonite with Cu²⁺ enhanced the antibacterial activity. The Cu*AAM, Cu*Na-MMT and Cu*Ca-MMT reduced the bacterial plate counts by 98.6%, 97.5% and 95.6%. Attempts were made to study the desorption of Cu²⁺ by washing with sterile physiological saline solution for 24 h. The washing solutions did not show a significant reduction of the bacterial counts, while the washed Cu-MMT retained their full antibacterial activity. Results from time-depending studies showed that the reduction of the bacterial counts by Cu-MMT increased during 24 h. The ranking of antibacterial activity of the three Cu-MMT was as Cu*AAM > Cu*Na-MMT > Cu*Ca-MMT. E. coli thrived optimally in a pH range from 5 to 7. Beyond this range, the bacterial counts decreased as the pH reduced the viability of the bacteria. The ranking of antibacterial activity of Cu-MMT was not affected by pH. The mechanism by which bacterial counts are reduced may involve the enhanced affinity of Cu-MMT for E. coli K₈₈ and the antibacterial activity of Cu²⁺.     

A cationic alternating copolymer composed of ornithine and glycine with an ordered sequence for enhanced bacterial activity

The chains and segments of unordered cationic polypeptides are complex and may produce unexpected biological activities. Herein, the Ugi's 4CC reaction is adopted to synthesize a cationic alternating copolymer comprising ornithine and glycine (poly(Orn-alter-Gly)) with an ordered sequence for enhanced bacterial resistance. In this technique, potassium isocyanate, 4-(N-carbobenzyloxyamino)-1-butyraldehyde and 1-(4-Methoxyphenyl)ethylamine react to produce MPE-substituted poly(Orn-alter-Gly) in one step without using a catalyst and then poly(Orn-alter-Gly) is obtained by removing the N-(1-p-methoxyphenethyl) (MPE) group. ¹H NMR, Fourier transform infrared spectroscopy, and automatic amino acid analysis confirm that ornithine and glycine are linked alternately in the poly(Orn-alter-Gly) chains. Both MPE-substituted poly(Orn-alter-Gly) and poly(Orn-alter-Gly) have excellent antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa as well as excellent biocompatibility. The synthesis strategy and materials provide new information on how to obtain ordered sequence cationic polypeptides.     

Quaternarized cationic poly[(vinyl chloride)-co-(vinyl chloroacetate)] binary copolymer as non-migration antibacterial additive in PVC matrix

Antibacterial polyvinyl chloride (PVC) materials have drawn considerable attention since their wide application in medical devices. The objective of this study is to develop a novel quaternary ammonium cationic vinyl chloride copolymer, which can be potentially used as antibacterial additive in PVC matrix. Initially, the low average-number molecular weight poly[(vinyl chloride)-co-(vinyl chloroacetate)] (PVC-co-PVCA) is synthesized by precipitation copolymerization. Subsequently, quaternary ammonium cationic moieties with different lengths of alkyl chains are introduced into the copolymers via quaternization reaction between alkyl-dimethyl tertiary amines with acyl chloride groups. The successful synthesis of PVC-co-PVCA and quaternarized copolymers are carefully confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance (1H NMR), and x-ray photoelectron spectroscopy. The antibacterial behaviors of the quaternarized copolymers and its blends with PVC are investigated. The results reveal that all the PVC blends containing at least 5% by weight of quaternarized copolymer have superior bacteriostasis ratio (>99.6%) against both Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) due to the incorporation of quaternary ammonium groups. Meanwhile, the cationic copolymer exhibits excellent antifouling and much lower migration rate (<0.4%). These interesting consequences endow the quaternarized copolymers as alternative antibacterial agents possess a great deal of potential for use in PVC materials.