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1.
Chitosan (CS) grafted poly[(acrylic acid)‐co‐(2‐hydroxyethyl methacrylate)] (CS‐g‐poly(AA‐co‐HEMA)) at different molar ratios of AA and HEMA, and the associated nanocomposite hydrogels of CS‐g‐poly(AA‐co‐HEMA)/mica were synthesized by radical copolymerization. The grafting positions at the amino or hydroxyl groups in the CS were identified by Fourier transform infrared spectroscopy. CS‐g‐poly(AA‐co‐HEMA) hydrogels were intercalated in the mica and the amount of hydrogel insertion did not affect the spacing of the silicate layers in mica. The higher mica loadings produced a rougher surface of the nanocomposite hydrogel. The water absorbency of the CS‐g‐poly(AA‐co‐HEMA)/mica nanocomposite hydrogels decreased with increasing levels of mica loading to a lower level than those of the CS‐g‐poly(AA‐co‐HEMA) hydrogels. Both CS‐g‐poly(AA) and CS‐g‐poly(AA‐co‐HEMA)/mica nanocomposite hydrogels exhibited a higher antiproliferative activity against Staphylococcus aureus than did the neat CS hydrogel with CS‐g‐poly(AA) revealing a very pronounced minimum inhibition concentration (MIC) of 1.56 mg mL?1. The extent of mica loading in the CS‐g‐poly(AA‐co‐HEMA) nanocomposite hydrogels did not affect the MIC (12.5 mg mL?1). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

2.
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   

3.
Hydrogel silver nanocomposites have been used in applications with excellent antibacterial performance. Acrylic acid (AA)/itaconic acid (IA) hydrogels silver nanocomposites were prepared and applied as a coating on a textile substrate. Hydrogel matrices were synthesized first by the polymerization of an AA/IA aqueous (80/20 v/v) solution and mixed with 2‐2‐azobis(2‐methylpropionamide) diclorohydrate and N,N′‐methylene bisacrylamide until the hydrogel was formed. Silver nanoparticles were generated throughout the hydrogel networks with an in situ method via the incorporation of the silver ions and subsequent reduction with sodium borohydride. Cotton (C) and cotton/polyester (CP) textile fibers were then coated with these hydrogel silver nanocomposites. The influence of these nanocomposite hydrogels on the properties of the textile fiber were investigated by infrared spectroscopy (attenuated total reflectance), scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and antibacterial tests against Pseudomona aeruginosa and Staphylococcus aureus. The better conditions, in which no serious aggregation of the silver nanoparticles occurred, were determined. It was proven that the textiles coated with hydrogels containing nanosilver had an excellent antibacterial abilities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2713–2721, 2013  相似文献   

4.
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   

5.
Chitosan (CS) has biocompatibility and biodegradability, but the bulk CS hydrogel/membranes with its poor strength and limited antibacterial property could not satisfy the practical application. Here green dissolving/regeneration and in situ reduction strategy was combined to construct high strength antibacterial CS membranes. First nanofibrous CS hydrogels were constructed through dissolving CS in LiOH/KOH/urea aqueous system via freezing–thawing process followed regeneration. Then, Ag NPs were immobilized along CS nanofibers through in situ reductions of Ag + by the NH2 group of CS. The obtained NCM-Ag composite dry membranes are easy for storing and can quick switch to nanofibrous hydrogels as absorbing water. Size of Ag NPs can be controlled to very small until 2 nm by concentration and limited space network. Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer indicated the forceful grasp ability of CS nanofibers to Ag NPs for a stable binding, mechanical property was enhanced over 100Mpa as the nanofibrous structure and chain linked by Ag coordination. The NCM-Ag membranes had excellent antibacterial activities against both Staphylococcus aureus and Escherichia coli. Moreover, such nanofibrous CS membrane exhibited good adhesive ability to tissues. Combining all these properties, NCM-Ag membranes would be potential as antibacterial adhesion barrier to accelerate wound healing.  相似文献   

6.
Antimicrobial peptide (AMP) hydrogel is a novel biomaterial widely used in wound healing. However, there have been limited studies investigating the effect of AMP on hydrogel properties so far. Therefore, this study aimed to examine the influence of the AMP HX-12C on the chitosan/polyacrylic acid (CS/PAA) double-network (DN) hydrogel. The results showed that the mechanical properties of CS/PAA/HX-12C hydrogel are significantly improved compared with those of CS/PAA hydrogel. The maximum tensile stress increased from 41.0 to 258.5 KPa, and the compression stress required for 80% hydrogel deformation increased from 3.7 to 6.7 MPa. Furthermore, the thermal stability of CS/PAA/HX-12C showed a noticeable enhancement when compared with CS/PAA hydrogel. In addition, the CS/PAA/HX-12C hydrogel exhibited improved porosity and swelling performance. The addition of HX-12C significantly enhanced the antibacterial activity of the hydrogel against Escherichia coli and methicillin-resistant Staphylococcus aureus. Cytotoxicity test showed that the viability of L929 cell remained above 90% after treatment with CS/PAA/HX-12C hydrogel extract, indicating the good biocompatibility. In conclusion, AMP assuredly enhances the mechanical property, swelling performance and antimicrobial activity of hydrogel. The CS/PAA/HX-12C hydrogel shows potential for use as anti-infective medical material.  相似文献   

7.
Chitosan (CS) is a semi‐natural polymer with supreme biological function, while the strong interchain hydrogen bonds cause poor water solubility and limit its broader use. To break the semi‐rigid structure of CS, a kind of CS modified by adamantane (AD‐CS) was successfully synthesized by amidation reaction with 1‐(3‐dimethylaminopropyl)‐3‐ethylcarbodiimide hydrochloride as catalyst. The chemical structure of AD‐CS was characterized by Fourier transform infrared spectroscopy and 1H NMR. The AD substitution degree of CS is around 2%, calculated by 1H NMR. A soft and transparent hydrogel composed of hydrogen bonds was obtained directly by simply adding a certain amount of water under mild conditions. Rheological measurements were carried out to research the mechanism of hydrogel formation by measuring the influence of different additives and conditions on the AD‐CS hydrogel. Reinforced hydrogels were prepared by freezing and thawing. The mechanical strength and self‐healing property of reinforced and pristine hydrogels were assessed with an oscillatory rheometer. The modulus of the reinforced hydrogel was obviously enhanced without much loss of self‐healing property. Other properties such as adhesion, injectability and temperature response were also studied. These injectable and self‐healing hydrogels show potential value in medical care. Additionally, this is a new method to design CS hydrogels with their original interchain hydrogen bonds. © 2019 Society of Chemical Industry  相似文献   

8.
Chitosan hydrogels were prepared from water soluble chitosan derivatives (chitosan‐MA‐LA, CML) by photoinitiating polymerization under the existence of Irgacure2959 and the irradiation of UV light. The CML was obtained by amidation of the amine groups of chitosan with lactic acid and methacrylic acid. Gelation time of the hydrogel could be adjusted within a range of 5–50 min, and controlled by factors such as the degree of MA substitution, initiator concentration, existence of oxygen, and salt. The dry hydrogel adsorbed tens to hundred times of water, forming a highly hydrated gel. The swelling ratio was smaller at the higher degree of MA substitution, higher pH, and higher salt concentration. Rheological test showed that the hydrogel is elastomeric in the measuring frequency range, with a storage modulus and loss modulus of 0.8–7 kPa and 10–100 Pa, respectively. In vitro culture of chondrocytes demonstrated that the cells could normally proliferate in the extractant of the hydrogels, showing no cytotoxicity at lower initiator concentration. By contrast, the extractant of the hydrogel made by the redox initiating system, i.e., ammonium persulfate (APS) and N,N,N′,N′‐tetramethylethylenediamine (TEMED), showed apparent cytotoxicity. Thus, the chitosan hydrogels initiated by the Irgacure2959 have better comprehensive properties, in particular better biocompatibility, and are more suitable for biomedical applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

9.
Novel Chitosan-cyclohexanone Mannich based hydrogel nanoparticles (CCMb1-4) were prepare via the reaction of chitosan with different concentration of 2, 6-bis (piperidin-1-ylmethyl) cyclohexanone. 2HCl (1%, 5%, 10% and 15% wt/wt) at 70–80°C for 7 h. These hydrogels were subjected to equilibrium swelling studies at room temperature in solutions of pH 2, 4, 6 and 8. The (CCMb1-4) showed maximum percent swellability at pH = 2.0. Furthermore, the swelling of the (CCMb1-4) followed Fickian diffusion. This preliminary investigation of chitosan-based interpolymeric hydrogels showed that they may be exploited to expand the utilization of these systems in drug delivery applications.  相似文献   

10.
A novel trilayered controlled‐release nitrogen, phosphorous, and potassium (NPK) fertilizer hydrogel was prepared by dipping the NPK fertilizer granules sequentially in 7% w v?1 poly(vinyl alcohol) (PVA) and 2% w v?1 chitosan (CS) solutions and then cross‐linking the CS layer (cross‐CS) via glutaraldehyde vapor deposition. Different NPK fertilizer hydrogels were then synthesized by inverse suspension polymerization of the dried PVA/cross‐CS bilayer‐coated fertilizer granules in various molar ratios of acrylamide (AM) and acrylic acid (AA) monomers, and polymerization with varying molar ratios of ammonium persulfate, N,N,N′,N′‐tetramethylethylenediamine and N,N′‐methylenebisacrylamide (N‐MBA). The water dissolution time of the obtained PVA/cross‐CS/poly (AA‐co‐AM) trilayer‐coated NPK fertilizer hydrogel granules was prolonged, while the water absorbency increased with increasing AA contents, and decreased with increasing N‐MBA contents in the outer poly(AA‐co‐AM) coating. The optimal trilayer‐coated NPK fertilizer hydrogel obtained released 84 ± 18, 63 ± 12, and 36 ± 15% of the N, P, and K nutrients, respectively, after a 30‐day immersion in water. The release phenomena of the N, P, and K nutrients of the fertilizer hydrogel obeyed both the Korsmeyer‐Peppas and Ritger‐Peppas models with a pseudo‐Fickian diffusion mechanism. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41249.  相似文献   

11.
Semi‐interpenetrating polymer network hydrogels with different compositions of chitosan (Cs), acrylic acid, and citraconic acid were synthesized via free‐radical polymerization with ethylene glycol dimethacrylate as a crosslinker. The variations of the swelling percentages of the hydrogels with time, temperature, and pH were determined, and Cs–poly(acrylic acid) (PAA) hydrogels were found to be most swollen at pH 7.4 and 37°C. Scanning electron micrographs of Cs–PAA and Cs–P(AA‐co‐CA)‐1 (Cs‐poly(acrylicacid‐co‐citraconir acid)?1) were taken to observe the morphological differences in the hydrogels. Although the less swollen hydrogel, Cs–P(AA‐co‐CA)‐1, had a sponge‐type structure, the most swollen hydrogel, Cs–PAA, displayed a uniform porous appearance. Fluconazole was entrapped in Cs–P(AA‐co‐CA)‐1 and Cs–PAA hydrogels, and the release was investigated at pH 4.0 and 37°C. The kinetic release parameters of the hydrogels (the gel characteristic constant and the swelling exponent) were calculated, and non‐Fickian diffusion was established for Cs–PAA, which released fluconazole much more slowly than the Cs–P(AA‐co‐CA)‐1 hydrogel. A therapeutic range was reached at close to 1 h for both hydrogels. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

12.
An antibacterial hydrogel wound dressing was successfully synthesized by the gamma irradiation method. A gelatin solution was mixed with a poly(vinyl alcohol) (PVA) solution of similar concentrations at different weight ratios of 100 : 0, 80 : 20, and 60 : 40 w/w, and irradiated at 30, 40, or 50 kGy. The testing of physical properties showed that the addition of PVA could improve both durability and mechanical integrity. The 60 : 40 hydrogels irradiated at 30 kGy were optimal, and chosen to add silver nitrate at 0.25, 0.50, 0.75, or 1.00 wt % (based on the solid content) to improve the antibacterial properties. After gamma irradiation, silver nanoparticles (AgNPs) were formed. The AgNP/gelatin/PVA hydrogels were characterized for physical properties, cytotoxicity, and antibacterial activity. The AgNP/gelatin/PVA hydrogels could be used as antibacterial wound dressings because they exhibited appropriate physical properties, noncytotoxicity, and could inhibit the growth of tested bacteria. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41138.  相似文献   

13.
Composite chitosan/active carbon (AC) hydrogels were elaborated by a novel route, consisting in exposing the chitosan solution to ammonia vapors. This vapor‐induced gelation method was compared with the conventional elaboration process, a direct immersion of the chitosan solution in liquid ammonia. The hydrogels were characterized to evaluate their potential application as wound‐dressings, mostly regarding their morphology, mechanical properties, swelling behavior, and sorption capacities for malodorous compounds emitted from wounds as diethylamine (DEA). The influence of elaboration route, chitosan concentration, and AC incorporation was studied. The results show that freeze‐dried hydrogels have a porous asymmetric structure dependent on the chitosan concentration and which promotes exudates drainage. The nanostructure of the parent hydrogel is semi‐crystalline and slightly dependent on the gelation conditions. It confers on hydrogel an acceptable mechanical behavior (compressive modulus up to 1.08·105 Pa). Hydrogels including AC display enhanced sorption kinetics for DEA, with sorption capacities up to 49 mg g?1. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

14.
Abstract

Chitosan (CS) has been proposed for the use of electrically modulated drug delivery. However, the gel fatigue makes CS hydrogel difficult to achieve precise and prolonged drug release. In this study, laminated hydroxyapatite (HAp)/CS composite hydrogels were prepared via solution intercalation method. Cyclic electrostimulation test revealed that the fatigue of neat CS was significantly improved by incorporation of laminated HAp. It is detected by transmission electron microscopy that laminated HAp distributed disorderly in the CS matrix, and the dimension of the HAp lamella is ~150 nm. Furthermore, the in vitro cytotoxicity of 2HAp/CS was evaluated by optical microscopy, scanning electron microscopy and [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The prepared composite hydrogels exhibit improved swelling fatigue property and good biocompatibility, which will further provide a wide range of potential application in the drug delivery.  相似文献   

15.
The ammonium persulfate induced polymerization of acrylamide in the presence of silver nitrate (AgNO3) and N,N′‐methylenebisacrylamide as a crosslinking agent were used to prepare crosslinked hydrogels containing silver ions. Subjecting this hydrogel to reduction with sodium hydroxide brought to focus the nanosilver hydrogel composites. Characterization of the latter, including proof of existence of silver nanoparticles in the hydrogel, was made. The number of silver nanoparticles embedded in the hydrogel matrix was higher at higher concentration of AgNO3 used in the preparation of the nanosilver hydrogel composite. The characterization was performed by the use of ultraviolet–visible spectroscopy and transmission electron microscopy. The swellability of the hydrogel containing nanosilver particles was also studied, and the dependence of the swellability on the abundance of silver nanoparticles in the hydrogel composite was verified. It was further disclosed that the kinetic model matched the experimental data; meanwhile, the diffusion of water into the hydrogel was non‐Fickian type. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

16.
Herein, a new approach was applied to produce reduced graphene oxide (RGO)-based conductive hydrogel by using modified chitosan (CTS) as a primary constituent. A variety amounts of RGO (from 0 to 15%) were incorporated into the polymeric network generated by photopolymerization of CTS-graft-glycidyl methacrylate (CTS-g-GMA) and poly(ethylene glycol)diacrylate (PEGDA). The structures of hydrogels were confirmed by FT-IR, XRD, and SEM analyses. Water uptake capacity of hydrogels determined gravimetrically. L929 fibroblast cells were used for cytotoxicity test. According to conductivity measurements carried out by four-point probe technique, the highest conductivity (1.716 × 10−3 S/cm) was obtained when 10% RGO was encapsulated into the polymeric structure. From the results, it could be envisaged that electroconductive hydrogel (ECH) fabricated in this study could have a potential usage for biosensor applications in the future projects. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48008.  相似文献   

17.
Industrial expansion has increased the discharge of contaminated wastewater. Wastewater can be treated by adsorption with petroleum-based hydrogels but the materials are not biodegradable and therefore cause secondary toxic waste. In this work, hydrogel composites are prepared based on non-biodegradable polyacrylamide and biodegradable materials of cassava starch (CS) and poly(vinyl alcohol). The effect of CS content on the porous structure is studied. The highest water absorption capacity of 74 g g−1 is obtained from a hydrogel 30 wt% of CS. Within 4 h, the hydrogel effectively adsorbs the cationic dyes methylene blue (MB) and crystal violet, and the anionic dyes congo red and reactive orange. The maximum adsorption capacity toward MB is 993 mg g−1. Experimental data indicate a monolayer adsorption via chemisorption. Silica-coated ZnO photocatalyst particles are synthesized via a sol–gel method and coated on the outer surface of the hydrogel. Under sunlight, the hydrogel composite degrades almost 90% of adsorbed dye. The hydrogel composite is capable of effective photodegradation for at least three cycles under artificial UV irradiation and four cycles under sunlight, but adsorption capacity remains higher than 80% at the eighth cycle. The hydrogel composite also shows antibacterial activities, indicating an additional beneficial property for industrial wastewater treatment.  相似文献   

18.
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 (Mn: 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.  相似文献   

19.
In this study, it has been investigated that the incorporation of poly(ethylene glycol), (PEG) and 4‐styrenesulfonic acid sodium salt, (NaSS) into acrylamide, (AAm) hydrogel during free radical solution polymerization synthesis. Poly (ethylene glycol)dimethacrylate, (PEGDMA) was used as a multifunctional crosslinker in polymerization. The main purpose of this study was to combine both monomers and a polymer in a new polymeric system. Dye sorption properties of hydrogels and semi IPNs were investigated by using cationic dye such as Union Green B (Janus Green B, UGB). Swelling and sorption studies were carried out at 25°C. For structural characterization, FTIR analysis was made. The equilibrium percentage swelling (Seq%) ranges are 660–1330% for AAm/NaSS hydrogels and 580–1310% for AAm/NaSS/PEG semi IPNs. To determine the sorption behaviors of cationic dye UGB, some sorption parameters such as sorption capacity (q), adsorption percentage (Ads%) and partition coefficient (Kd) of the hydrogels were investigated. Binding characterization has been studied by Langmuir linearization method. The sorption capacity values of the hydrogel systems were changed between 1.24 × 10?4 and 4.05 × 10?4 mol g?1. The values of Ads% of the hydrogels were changed among 18?67%, and the values of Kd of the hydrogels were between 0.22 and 2.02. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers  相似文献   

20.
This research introduces a novel dressing for burn wounds, containing silver nanoparticles in hydrogels for infected burn care. The 2‐acrylamido‐2‐methylpropane sulfonic acid sodium salt hydrogels containing silver nanoparticles have been prepared via ultraviolet radiation. The formation of silver nanoparticles was monitored by surface plasmon bands and transmission electron microscopy. The concentration of silver nitrate loaded in the solutions slightly affected the physical properties and mechanical properties of the neat hydrogel. An indirect cytotoxicity study found that none of the hydrogels were toxic to tested cell lines. The measurement of cumulative release of silver indicated that 70%–82% of silver was released within 72 hr. The antibacterial activities of the hydrogels against common burn pathogens were studied and the results showed that 5 mM silver hydrogel had the greatest inhibitory activity. The results support its use as a potential burn wound dressing. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40215.  相似文献   

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