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1.
This article reports the temperature‐sensitive, green tea (GT)‐based silver‐nanocomposite hydrogels for bacterial growth inactivation. The temperature‐sensitive hydrogels were prepared via free‐radical polymerization using temperature‐sensitive N‐isopropylacrylamide (NIPAM) monomer with GT as the hydrogel matrix. The nanocomposite hydrogels were encapsulated with silver ions via swelling method, which was later reduced to silver nanoparticles using Azadirachta indica leaf extract. The temperature‐sensitive silver nanocomposite hydrogels were analyzed by using Fourier transforms infrared, UV–visible spectroscopy, differential scanning calorimetry–thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The prepared hydrogels exhibited higher phase volume transition temperature than the NIPAM. The inhibition zone study of the inactivation of bacteria on the developed hydrogels was carried out against Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus), which revealed that the prepared hydrogels are helpful for the inactivation of these bacteria due to the high stabilization of antibacterial properties of the silver nanoparticles. The developed hydrogels are promising for biomedical applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45739.  相似文献   

2.
The preparation of poly(hexylacrylate)core‐poly(ethyleneglycol methacrylate)shell (PHA‐co‐PEGMA) nanogels, to be used as fillers in nanocomposite hydrogels, is reported. Stable nanogels with particle sizes between 90–300 nm were obtained varying the conditions of synthesis. The synthesis recipe of the nanogels could be easily scaled up. Purified and dispersed nanogels in aqueous solution were used as soft fillers for poly(2‐hydroxyethyl methacrylate) (PHEMA) hydrogels, crosslinked with ethylene glycol dimethacrylate (EGDMA). The obtained nanocomposite hydrogels exhibit a larger swelling capacity and a higher thermal stability in comparison with the non‐filled PHEMA hydrogels. Young, storage, and lost moduli, increase largely, in the better case up to 72.5% in the swollen state; while in the dry state the storage modulus increase up to 4.7 fold with a very low load on nanogels (0.64 wt%); resulting in biomaterials with improved properties with potential applications in medical devices. POLYM. ENG. SCI., 59:170–181, 2019. © 2018 Society of Plastics Engineers  相似文献   

3.
Both hydrophilic and antifouling surfaces were prepared on silicone hydrogels with poly(ethylene glycol) methyl ether acrylate (PEGMA) grafted by UV-induced radical polymerization. The PEGMA-grafted silicone hydrogels were characterized by graft yield and static water contact angle measurements. According to the results, the graft yield reached a maximum at 8 min of UV exposure time and 20 wt% PEGMA concentration. The modified silicone hydrogels possessed hydrophilic surfaces with the lowest water contact angle of 36°. The oxygen permeability and transparency of the PEGMA-grafted silicone hydrogels were as high as the unmodified silicone hydrogel. The mechanical property of silicone hydrogels was maintained at about 95% of the tensile strength and elastic modulus after the PEGMA grafting. The in vitro single protein adsorption on the PEGMA-grafted silicone hydrogels decreased by 70–80% compared to the unmodified silicone hydrogel. The PEGMA-grafted silicone hydrogel is expected to be a novel biomaterial, which possesses excellent surface hydrophilicity, antifouling property, oxygen permeability, and mechanical property. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

4.
Acrylic acid was crosslinked with N,N′‐methylenebisacrylamide and converted to bioactive hydrogels by neutralization with different amino containing compounds. Several amino containing compounds were used such as 2‐aminopyridine, triethanol amine, hexamethylenetetramine (HMTA), pyridine, and imidazole. The best crosslinker ratio was determined in addition to the maximum absorbed water in different mediums. The antibacterial activity of the prepared gels were examined against examples of Gram‐positive (Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli) using agar plate method. The study was extended by evaluating one of prepared gels in columns as models for water filters. All prepared gels showed antibacterial action in agar plate method against both bacterium and the column method using one of the prepared gels showed excellent filtration and biocidal action. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

5.
In this study, a new cationic monomer 2‐(3‐indol‐yl)ethylmethacrylamide (IEMA) derived from tryptamine was synthesized in a single step and characterized by Fourier transform infrared (FTIR), 1H‐NMR, and 13C‐NMR. Then, one‐step preparation of novel poly[2‐hydroxyethylmethacrylate‐c‐2‐(3‐indol‐yl)ethylmethacrylamide], or p(HEMA‐c‐IEMA), copolymeric hydrogels has been performed successfully with IEMA and 2‐hydroxyethylmethacrylate (HEMA) as monomers using free radical aqueous polymerization. The hydrogels were characterized with scanning electron microscopy, FTIR, elemental analysis, thermogravimetric analysis, and texture profile analysis instruments. p(HEMA‐c‐IEMA) hydrogels were used for swelling, diffusion, drug release, and antibacterial activity studies. The drug‐release behavior of the hydrogels was determined as a function of time at 37 °C in pH 1.2 and 7.2. The swelling and drug‐release studies showed that an increased IEMA amount caused a higher increase in swelling and drug‐release values. Additionally, zero‐order, first‐order, and Higuchi equation kinetic models were applied to the drug‐release data, and the data fit well in the Higuchi model, and the Peppas power‐law model was applied to the release mechanism. Finally, the antibacterial activities of the hydrogels were screened against Gram‐positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Salmonella typhimurium). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45550.  相似文献   

6.
Injectable, de‐crosslinkable, and thermosensitive hydrogels are obtained by hydrazide‐functionalized poly(N‐isopropylacrylamide) and aldehyde‐functionalized dextrin through in situ crosslinked method. Natural based and degradable starch nanoparticles (SNPs) are used as fillers in order to improve mechanical property of hydrogels. Internal morphology, dynamic modulus, thermosensitivity property, de‐crosslinking performance, drug release, and in vitro cytotoxicity of hydrogels are investigated. Results show that SNPs disperse well throughout hydrogel and have no significant influence on gelation time and de‐crosslinking performance. Elasticity property of composite hydrogel prepared from 9.0 wt % precursors with 1.5 wt % fillers is improved significantly by SNPs and maximum storage modulus reaches 399.2 kPa, but 89.6 kPa of unreinforced hydrogels. Hydrogels exhibit good thermosensitive performance at alternating cyclic temperature of 25 and 37 °C. Doxorubicin hydrochloride‐loaded hydrogels can release more than 25 days. No significant cytotoxicity to L929 fibroblast cells is observed through a CCK‐8 assay for hydrogels, precursors, and SNPs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45761.  相似文献   

7.
A novel amphiphilic hydrogel based on poly(2‐methyl‐2‐oxazoline)‐b‐poly(dimethyl siloxane) (PMeOx–PDMS) block copolymer was developed. First of all, PMeOx–PDMS macromonomer was synthesized by coupling mono‐hydroxylated PMeOx with PDMS followed by end‐capping with methacrylate group. The structures of each step were characterized by NMR and titration. After that, silicone hydrogels were prepared by UV‐initiated copolymerization of PMeOx–PDMS macromonomer with monomers such as 2‐hydroxyethyl methacrylate in the presence of a crosslinker. Measurements of the hydrogels' water contact angle, equilibrium water content, and tensile properties showed that the hydrogels possessed better hydrophilic surface, higher water content, and better ion permeability with the increase of the content of the macromonomer PMeOx–PDMS. Meanwhile, the tensile strength and Young's modulus of the hydrogels decreased slightly. Protein adsorption tests showed that the hydrogels had strong antifouling ability after the incorporation of PMeOx. This newly described hydrogel demonstrated attractive properties to serve as ophthalmic biomaterial. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39867.  相似文献   

8.
In this work, chitosan hydrogel has been synthesized and used to impart pH‐sensitivity and antimicrobial finish to cotton fabric. In order to enhance the incorporation rate of hydrogel, anionic, and cationic activation of the textile surface was applied and then compared. The antibacterial activity of the fabric was then studied. The results revealed an enhancement of the antibacterial activities of the modified fabrics against Escherichia coli, Listeria monocytogene, and Staphylococcus aureus bacteria's. The capacity of material to respond to pH change was studied and confirmed using contact angle method. The anionic fabric treated with hydrogel showed a better pH‐responsiveness. Scanning electron microscopic testing results has also confirmed that the deposition of hydrogel was clearly better with the anionic activation. The characteristics of breathability of the fabrics were analyzed. The results show that the moisture management behavior of the finished materials is significantly better than the control one. Although the permeability to air has reduced by 10%, the permeability to water vapor remained practically unchanged. Furthermore, the effects of the antibacterial finishing on the physical properties of the cotton fabrics were also investigated. It was established that the functionalized samples have changed structure parameters, thickness, air permeability, tensile strength, and resistance to wrinkles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46645.  相似文献   

9.
Nano‐TiO2/carboxymethyl chitosan (CMCS)/poly(vinyl alcohol) (PVA) ternary nanocomposite hydrogels were prepared by freezing–thawing cycles and electron‐beam radiation with PVA, CMCS, and nano‐TiO2 as raw materials. The presence of nano‐TiO2 nanoparticles in the composite hydrogels was confirmed by thermogravimetry, Fourier transform infrared spectroscopy, and X‐ray powder diffraction. Field emission scanning electron microscopy images also illustrated that the TiO2/CMCS/PVA hydrogel exhibited a porous and relatively regular three‐dimensional network structure; at the same time, there was the presence of embedded nano‐TiO2 throughout the hydrogel matrix. In addition, the nano‐TiO2/CMCS/PVA composite hydrogels displayed significant antibacterial activity with Escherichia coli and Staphylococcus aureus as bacterial models. The antibacterial activity was demonstrated by the antibacterial circle method, plate count method, and cell density method. Also, with the Alamar Blue assay, the cytotoxicity of the composite hydrogel materials to L929 cells was studied. The results suggest that these materials had no obvious cytotoxicity. Thus, we may have developed a novel, good biocompatibility hydrogel with inherent photosensitive antibacterial activity with great potential for applications in the fields of cosmetics, medical dressings, and environmental protection. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44150.  相似文献   

10.
Medical‐grade polyvinyl chloride was modified with sodium ampicillin in a concentration range from 0 to 5 wt % by solvent casting technique using cyclohexanone and N,N‐dimethylformamide. The obtained polymeric systems were characterized by optical microscopy, tensile test, and scanning electron microscopy. In addition, in vitro antibacterial activity against Gram‐negative and Gram‐positive bacteria was determined by an agar diffusion test. Antibiotic release experiments were performed in distilled water and physiological saline solution, which were monitored by UV‐vis spectroscopy. The results showed a crucial role of the solvent on the morphology, antibacterial activity, and releasing characteristic of the ampicillin. Furthermore, a mathematical model was applied to data obtained from release study, to characterize the release kinetics of the ampicillin from the polyvinyl chloride‐antibiotic systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

11.
Hydrogels have been widely used as mild biomaterials due to their bio‐affinity, high drug loading capability and controllable release profiles. However, hydrogel‐based carriers are greatly limited for the delivery of hydrophobic payloads due to the lack of hydrophobic binding sites. Herein, nano‐liposome micelles were embedded in semi‐interpenetrating poly[(N‐isopropylacrylamide)‐co‐chitosan] (PNIPAAm‐co‐CS) and poly[(N‐isopropylacrylamide)‐co‐(sodium alginate)] (PNIPAAm‐co‐SA) hydrogels which were responsive to both temperature and pH, thereby establishing tunable nanocomposite hydrogel delivery systems. Nano‐micelles formed via the self‐assembly of phospholipid could serve as the link between hydrophobic drug and hydrophilic hydrogel due to their special amphiphilic structure. The results of transmission and scanning electron microscopies and infrared spectroscopy showed that the porous hydrogels were successfully fabricated and the liposomes encapsulated with baicalein could be well contained in the network. In addition, the experimental results of response release in vitro revealed that the smart hydrogels showed different degree of sensitiveness under different pH and temperature stimuli. The results of the study demonstrate that combining PNIPAAm‐co‐SA and PNIPAAm‐co‐CS hydrogels with liposomes encapsulated with hydrophobic drugs is a feasible method for hydrophobic drug delivery and have potential application prospects in the medical field. © 2018 Society of Chemical Industry  相似文献   

12.
A viable method for coating of cellulose fiber with quaternarized N‐halamine is reported in this article. The use of quaternary ammonium salt group in combination with N‐halamine group can reinforce the antibacterial activity. The chemical structure of as‐synthesized N‐halamine precursor 4‐(Bromo‐acetic acid methylester)‐4‐ethyl‐2‐ oxazolidinone (BEO) was characterized by 1H‐NMR. The cellulose fibers were characterized by Fourier transform infrared spectra and X‐ray photoelectron spectra. The spectra data confirmed that the quaternarized N‐halamine‐grafted cellulose fibers were successfully obtained. The antibacterial properties of functional fibers were challenged with both Gram positive and Gram negative bacteria. The antibacterial tests and showed that the as‐prepared antibacterial cellulose fibers exhibited powerful and rapid bactericidal performance against both Gram negative E. coli and Gram positive S. aureus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42702.  相似文献   

13.
Many efforts have been made to develop modern wound dressings to overcome limitations of traditional ones. Smart nanocomposite hydrogels are appropriate candidates. In this work, a novel responsive nanocomposite hydrogel based on poly(vinyl alcohol)/chitosan/honey/clay was developed and evaluated as a novel wound dressing. The morphology and properties of synthesized nanocomposite hydrogels loaded with honey as a drug model were investigated. The exfoliated morphology of nanocomposite was confirmed by X‐ray diffractometry. Swelling studies were performed at 20 and 37 °C at various pH. The results showed that swelling increased as a result of temperature rise and maximum swelling occurred at a pH of 2. In vitro release of honey was also studied at the same conditions. Corresponding results indicated faster honey release rate at higher pH values. MTT results exhibited no cytotoxicity in nanocomposite hydrogel system. Investigation of antibacterial activity revealed more than 99% antibacterial activity for proposed system. In vivo results confirmed the wound healing ability of developed system. Generally, appropriate properties of proposed system made it ideal in wound dressing applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46311.  相似文献   

14.
Ibuprofen‐loaded chitosan/gelatin (CS/GE) composite films were fabricated in this work. The morphology of the composite film was investigated using scanning electron microscopy. The functional groups of the composite film before and after crosslinking were characterized using Fourier transform infrared spectroscopy. Meanwhile, the mechanical properties, antibacterial performance, cytocompatibility, and hemostatic activity of the composite films were investigated. The results show that the amount of CS affected the mechanical properties and liquid uptake capacities of the composite films. The composite film showed better bactericidal activity against Staphylococcus aureus than Escherichia coli. In vitro drug‐release evaluations showed that crosslinking could control the drug‐release rate and period in wound healing. Both types of CS/GE and drug‐loaded CS/GE composite films also showed excellent cytocompatibility in cytotoxicity assays. The hemostatic evaluation indicated that the composite film crosslinked by glutaraldehyde in rabbit livers had a dramatic hemostatic efficacy. Therefore, ibuprofen‐loaded CS/GE composite films are potentially applicable as a wound dressing material. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45441.  相似文献   

15.
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  相似文献   

16.
Electrospun nanofibrous membranes (NFMs) with outstanding photochromic property, waterproof, and breathability have attracted considerable interest owing to their multifunctional applications in intelligent clothing, self‐cleaning, and protection. However, great challenges still remain in creating such functional materials. A novel waterproof–breathable membrane with robust photochromic property is fabricated by introducing photochromic microcapsule (PM) into electrospun thermoplastic polyurethanes (TPU) membranes. Compared with the pristine TPU NFMs, the composite TPU/PM membranes are endowed with reversible photochromic properties. In addition, the composite membranes not only exhibited a water contact angle of 137° and a milk contact angle of 130°, but also had integrated properties of modest water vapor transmittance rate of 19,278 g m?2 day?1, high air permeability of 962 mm s?1, low waterproofness of 2.813 kPa, and comparable tensile strength of 12.08 MPa. Furthermore, the convenience and efficiency of this fabrication process will allow for large‐scale production of the multifunctional NFMs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46342.  相似文献   

17.
In this study, a series of theophylline‐loaded calcium pectin gel films were prepared in three different Ca+2 concentrations with three different methods for wound dressing applications. Drug release performance of the films were investigated in four different medium pH in order to mimic wound healing pH conditions. Hydrogel films were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy and atomic force microscopy. Their absorbency (fluid handling), swelling behavior, dehydration rate, dispersion characteristic, dressing pH determination, water vapor permeability, oxygen permeability, surface contact angle, flexibility, Shore A hardness, mean mass per unit area and thickness were determined. The effect of the hydrogels on wound healing was evaluated with an in vitro wound healing assay. After evaluating all data, we suggested that the hydrogel film prepared with swelling method using 7% or 10% crosslinker and dried at 26 °C is more suitable for controlled drug release process. We showed that between pH 3.25 and 7.12 the form of the hydrogel did not change, and drug release was continuous. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46731.  相似文献   

18.
In this work we report the photopolymerization of poly(2‐hydroxyethyl methacrylate) (PHEMA) together with a hydrophilic chitosan derivate (carboxymethyl‐chitosan) to yield a semi‐interpenetrating polymer network (semi‐IPN) that was filled with poly(N‐vinylcaprolactam)/poly(ethylene glycol methacrylate) core–shell nanogels in order to enhance the mechanical properties of the resulting hydrogels. The mechanical properties of the nanofilled semi‐IPNs were found to be more suitable for wound dressing applications than the PHEMA hydrogel as described by dynamic mechanical analysis in dry form and submerged in water. This was evidenced by a higher Young's modulus and higher elongation at break in the semi‐IPNs compared to blank PHEMA hydrogels. Furthermore, when the hydrogels were filled with nanogels, there was an elongation at break similar to that of skin with only a slightly lower Young's modulus. © 2019 Society of Chemical Industry  相似文献   

19.
Amphoteric terpolymers of acrylic acid (AA), acrylamide (AM), and N,N′‐dimethyl‐N‐ethylmeth‐acryloxylethylammoniumbromide (DMAEA‐EB) with varied compositions P[AA‐AM‐(DMAEA‐EB)] were synthesized by inverse suspension polymerization. The components of P[AA‐AM‐(DMAEA‐EB)] were verified by FTIR spectroscopy. The water absorption ability and antibacterial activity of the copolymer against Escherichia coli(E. coli) and Staphylococcus hyicus(S. hyicus) suspended in sterilized physiological saline were investigated. The introduction of  N+R4 may increase the water absorbency of P[AA‐AM‐(DMAEA‐EB)] in some degree because of the excellent hydrophilicity of  N+R4. The AA‐AM‐(DMAEA‐EB) hydrogels exhibited high antibacterial activity against bacteria tested. The process of adsorption between live bacteria cells and resins was at least partially reversible. A peak of antibacterial efficiency existed with increasing contact time. The resin killed 96.6% E. coli organisms and 90.3% S. hyicus organisms, respectively, within 30 min of contact at dosage of 0.1g. The concentration of DMAEA‐EB has a special effect on the antibacterial activity of the polyampholytic hydrogels, which is different from polycation. It was observed that the antibacterial activity of the resin with 2 mol % of DMAEA‐EB is superior to the copolymers tested with other compositions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

20.
A highly hydrophilic block copolymer polyether block amide (PEBA) is modified with chloropropane diol (CPD) to impart antibacterial and antifungal properties to it without compromising with its breathability. The antibacterial properties of modified membranes are evaluated against Staphylococcus aureus (S. aureus, Gram positive) and Escherichia coli (E. coli, Gram negative) bacteria by membrane culture method. CPD plays an important role in the antibacterial property with the inhibition rate reaching 99.99% for CPD modified membranes which was 27.55% and 16.82% for pristine membrane (against S. aureus and E. coli respectively). The antifungal properties studied against Aspergllus niger, Penicillium pinophilum, Aureobasidium pullulans, Chaetomium globosum, and Trichoderma virens show heavy‐growth of fungi for pristine PEBA membrane while no growth was observed in case of CPD modified membranes. Breathability of membrane is determined in terms of water vapor transmission rate (WVTR) and it increase from 1496 g/m2/day to 2354 g/m2/day after modification. The membranes are characterized by FTIR‐ATR, SEM‐EDX, DSC, and TGA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46097.  相似文献   

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