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1.
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.  相似文献   

2.
A novel antibacterial material with surface immobilized polyvinylpyrrolidone‐iodine complex was synthesized facilely by a two‐step approach. First, N‐vinylpyrrolidone (NVP) was photografted onto polymeric substrates, and subsequently the surface‐grafted polyvinylpyrrolidone (PVP) underwent complexation of iodine. In the UV‐induced photografting process, PVP was efficiently grafted onto the polypropylene (PP) film surface by a unique film interlayer photopolymerization (FIP) technique; the grafting yield (Yg) could be controlled by varying the irradiation time or the monomer concentration. Further, we demonstrated that the grafted PVP chains could readily perform the complexation reaction with iodine as the homopolymer PVP does, which was characterized by UV–vis spectroscopy. The antibacterial activity of the modified polymer against Escherichia coli, Staphylococcus aureus, and Candida albicans was investigated. The results show that the modified PP film with surface‐immobilized PVP‐I complex has a desirable antibacterial property, with broad spectrum and high efficiency. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2026–2031, 2005  相似文献   

3.
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  相似文献   

4.
Cross‐linked cationic starches N‐(2‐hydroxyl)propyl‐3‐trimethyl ammonium starch chloride (CQS chloride), N‐(2‐hydroxyl)propyl‐3‐trimethyl ammonium starch iodide (CQS iodide), and N‐(2‐hydroxyl)propyl‐3‐trimethyl ammonium starch iodide–iodine (CQS triiodide) with the degree of substitution (DS) according to cationic groups from 0.04 to 0.62, as well as cross‐linked starch–iodine complexes were synthesized and tested as potential antibacterial agents. Cationic starch iodine derivatives were obtained during ion exchange reaction between CQS chloride and iodide or iodide–iodine anions in aqueous solutions. CQSDS≤0.3 chloride can form several types of iodine complexes, such as the blue amylose–iodine inclusion complex and ionic CQS+I?·(I2)m complex (m ≥ 1). The antibacterial activity of modified starches–iodine samples against different pathogenic bacterial cultures and contaminated water microorganisms was evaluated. CQS chloride and CQS iodide were found to be bacteriostatic. A strong antibacterial activity was characteristic of CQS triiodides in which molecular iodine is present in both ionic and inclusion complexes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

5.
Grafting of agar and κ‐carrageenan with polyvinylpyrrolidone (PVP, average molecular weight 10,000 D) in an aqueous medium at a pH of about 7 produced agar‐graft‐PVP and κ‐carrageenan‐graft‐PVP blends capable of forming hydrogels. The reaction was carried out with microwave irradiation in the presence of a water‐soluble initiator, potassium persulfate. Optimum microwave irradiation conditions for obtaining hydrogels of the grafted products were achieved. The structural characteristics and thermal stability of the grafted blends were studied by Fourier transform infrared, 13C‐NMR, and thermogravimetric analyses. Appearance of new IR bands at 1661, 1465, and 1426 cm?1 in the grafted products indicated the insertion of PVP into the polysaccharide structure. Powder X‐ray diffraction studies revealed the enhanced crystallinity in the products compared to in the control polysaccharides as well as PVP. Agar and κ‐carrageenan were grafted to a considerable degree, with 62.5 E % and 125 G % for agar‐graft‐PVP and 65.5 E % and 131 G % for κ‐carrageenan‐graft‐PVP. Optical micrographs of the grafted blends indicated considerable changes in the morphology of the agar and the κ‐carrageenan, substantiating the X‐ray diffraction data. A plausible mechanism for the crosslinking of PVP to agar and κ‐carrageenan is proposed. These hydrogels exhibited enhanced water‐holding capacity despite weaker gel strength than that in the respective control polysaccharides. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3654–3663, 2006  相似文献   

6.
Chitosan films have a great potential to be used for wound dressing and food‐packaging applications if their physicochemical properties including water vapor permeability, optical transparency, and hydrophilicity are tailored to practical demands. To address these points, in this study, chitosan (CS) was combined with polyvinylpyrrolidone (PVP) and graphene oxide (GO) nanosheets (with a thickness of ~1 nm and lateral dimensions of few micrometers). Flexible and transparent films with a high antibacterial capacity were prepared by solvent casting methods. By controlling the evaporation rate of the utilized solvent (1 vol % acidic acid in deionized water), self‐organization of GO in the polymer matrix was observed. The addition of PVP to the CS/GO films significantly increased their water vapor permeability and optical transmittance. A blue shift in the optical absorption edge was also noticed. Thermal analysis coupled with Fourier transform infrared spectroscopy suggested that the superior thermal stability of the nanocomposite films was due to the formation of hydrogen bonds between the functional groups of chitosan with those of the graphene oxide. An improved bactericidal capacity of the nanocomposite films against gram‐positive Staphylococcus aureus and gram‐negative Escherichia coli bacteria was also observed. Highly flexible, transparent (opacity of 6.95), and antimicrobial CS/25 vol % PVP/1 wt % GO films were prepared. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43194.  相似文献   

7.
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  相似文献   

8.
The O‐fumaryl ester (OFTMCS) of N,N,N‐trimethyl chitosan (TMCS) has been synthesized as a water‐soluble chitosan (CS) derivative bearing dual‐functional groups, with the aim of discovering novel CS derivatives with good water solubility and enhanced the antibacterial activity compared with unmodified CS. OFTMCS was characterized by FT‐IR, 13C NMR, XPS, XRD and Zeta potential analyses. The XPS results indicated that the degree of substitution (DS) on the C2‐NH2 group of the CS was 0.78, and that the DS on its C6‐OH group was 0.31. The TGA results showed that the thermal stability of OFTMCS was lower than that of unmodified CS. The antibacterial activities of OFTMCS were investigated by assessing the mortality rates of the representative Gram‐positive and Gram‐negative bacteria Staphylococcus aureus and Escherichia coli, respectively. The results indicated that OFTMCS exhibited superior antibacterial activity to CS at a lower dosage. The synthesis of CS derivatives bearing dual‐functional groups could therefore be used as a promising strategy to enhance the antibacterial activity of CS. The antimicrobial mechanism of action of OFTMCS was discussed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42663.  相似文献   

9.
Bio‐nanocomposite films based on chitosan/polyvinylpyrrolidone (CS/PVP) and graphene oxide (GO) were processed using the casting/evaporation technique. It has been found that the three components of bio‐nanocomposites can be easily mixed in controlled conditions enabling the formation of thick films with high quality, smooth surface and good flexibility. Structural and morphological characterizations showed that the GO sheets are well dispersed in the CS/PVP blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and GO sheets thus improving their properties. It has been found that the water resistance of the CS/PVP blend is improved, and the hydrolytic degradation is limited by addition of 0.75 and 2 wt % GO. The modulus, strength, elongation and toughness of the bio‐nanocomposites are together increased. Herein, the steps to form new bio‐nanocomposite films have been described, taking the advantage of the combination of CS, PVP and GO to design the aforementioned bio‐nanocomposite films, which allow to have extraordinary properties that would have promising applications as eventual packaging materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41042.  相似文献   

10.
Three polyesters—poly(ethylene terephthalate), poly(2‐methyl‐1,3‐propylene terephthalate‐co‐ethylene terephthalate), and poly(1,4‐cyclohexylene terephthalate‐co‐ethylene terephthalate)—were preirradiated with 60Co‐γ‐rays. Then, acrylic acid and N‐vinylformamide were grafted to these irradiated fibers. Fibers grafted with N‐vinylformamide were further hydrolyzed with acid so that the amide groups would convert into amino groups, and they were treated with glutaraldehyde so that aldehyde groups would be introduced. Chitosan or chitooligosaccharide was then grafted to these fibers via either esterification or imine formation. Four pathogenic bacteria—methicillin‐resistant Staphylococcus aureus‐1 (MRSA), Staphylococcus aureus‐2, Escherichid coli, and Pseudomonas aeruginosa—were tested to determine the antibacterial activities of chitosan‐grafted and chitooligosaccharide‐grafted fibers. The results showed that grafting chitosan via imine formation could achieve a higher surface density for amino groups and give higher antibacterial activity to those four bacteria tested. The antibacterial activity for E. coli was the highest and that for MRSA was the lowest among the four bacteria tested. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2977–2983, 2002  相似文献   

11.
2‐Hydroxyethyl methacrylate (HEMA) based polymeric hydrogels were synthesized by free‐radical redox bulk polymerization technique using 1% ethyleneglycol dimethacrylate (EGDMA) as crosslinking monomer and ammonium persulfate (APS) and N,N,N′,N′‐tetramethyl ethylenediamine (TEMED) as redox initiator. Polymeric hydrogel samples were loaded with solid elemental iodine. Thermal and physical characteristics of polymer before loading and after 3 months release of iodine were evaluated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). On immersing in water, different forms of iodine were released from the hydrogel device. The amount and rate of release of I? and I were measured by analytical techniques. Released iodine species showed broad spectrum antimicrobial properties and release was sustained for about 120 days. Polymeric hydrogel iodine‐based system developed can be used as a device for controlled release of iodine species at concentration levels sufficient for disinfection to get potable water. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3334–3340, 2007  相似文献   

12.
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   

13.
把壳聚糖改性成O’O-月桂酰壳聚糖,并通过交联法制备了O’O-月桂酰壳聚糖/聚乙烯吡咯烷酮(O’O-LCS/PVP)水凝胶,研究了聚乙烯吡咯烷酮质量比、反应温度、反应时间对水凝胶溶胀性能的影响,通过红外光谱法比较了CS和O’O-LCS结构上的不同。以布洛芬为模型药物研究了其释药性能。  相似文献   

14.
Chitosan is a promising candidate as an antimicrobial agent in food packaging materials and biomaterials due to its biocompatibility, biodegradability, non‐toxicity and biocidal activity. In this study, chitosan derivatives, α‐(5,5‐dimethyl hydantoin amino)‐chitosan (CS‐HDH), were synthesized. The CS‐HDH nanospheres were prepared by ionic gelation method and characterized by SEM, FT‐IR, XRD, and TGA‐DTG. The prepared novel chitosan nanospheres in the range of 200–300 nm had good dispersibility. The CS‐HDH nanospheres were used to prepare antibacterial PVA hybrid films by solvent evaporation technique. The surface morphology and thermal property of hybrid films were measured by SEM, AFM, and TGA‐DTG. The results of antibacterial test showed that the hybrid film with 1.24 × 1018 atoms/cm2 of active chlorine exhibited excellent antibacterial properties against Staphylococcus aureus and Escherichia coli O157:H7, and all of bacteria could be inactivated within 5 min. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44204.  相似文献   

15.
Tetracycline hydrochloride loaded poly (vinyl alcohol)/chitosan/ZrO2 (Tet‐PVA/CS/ZrO2) hybrid nanofibers were fabricated via electrospinning technique. The representative weight ratio of PVA/CS at 3 : 1 was chosen to fabricate drug carrier PVA/CS/ZrO2 nanofibers. The drug carrier showed a decrease in average diameter with the increase of ZrO2 content at given conditions, and the nanofibers were uneven and interspersed with spindle‐shape beads with ZrO2 content at 60 wt % and above. The networks linked by hydrogen and Zr–O–C bonds among PVA, CS, and ZrO2 units resulted in the improving of thermal stability and decreasing of crystallinity of the polymeric matrix. Moreover, the incorporation of ZrO2 endowed the fibers with ultraviolet shielding effect ranged from 200 to 400 nm. The Tet loading dosage had no obvious effect on the morphology and size of the medicated nanofibers at Tet content below 8 wt %, but interspersed with spindle‐shaped beads when Tet content increased to 10 wt %. The Tet‐PVA/CS/ZrO2) nanofibers showed well controlled release and better antimicrobial activity against Staphylococcus aureus, and the Tet release from the medicated nanofibers could be described by Fickian diffusion model for Mt /M< 0.6. These medicated nanofibers may have potential as a suitable material in drug delivery and wound dressing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42506.  相似文献   

16.
A new type of amphiphilic quaternary ammonium chitosan derivative, 2‐N‐carboxymethyl‐6‐O‐diethylaminoethyl chitosan (DEAE–CMC), was synthesized through a two‐step Schiff base reaction process and applied to drug delivery. In the first step, benzaldehyde was used as a protective agent for the incorporation of diethylaminoethyl groups to form the intermediate (6‐O‐diethylaminoethyl chitosan). On the other hand, NaBH4 was used as a reducing agent to reduce the Schiff base, which was generated by glyoxylic acid, for the further incorporation of carboxymethyl groups to produce DEAE–CMC. The structure, thermal properties, surface morphology, and diameter distribution of the resulting chitosan graft copolymers were characterized by Fourier transform infrared spectroscopy, 1H‐NMR, thermogravimetric analysis, differential scanning calorimetry, X‐ray powder diffraction, scanning electron microscopy, and laser particle size analysis. Benefiting from the amphiphilic structure, DEAE–CMC was able to be formed into microspheres in aqueous solution with an average diameter of 4.52 ± 1.21 μm. An in vitro evaluation of these microspheres demonstrated their efficient controlled release behavior of a drug. The accumulated release ratio of vitamin B12 loaded DEAE–CMC microspheres were up to 93%, and the duration was up to 15 h. The grafted polymers of DEAE–CMC were found to be blood‐compatible, and no cytotoxic effect was shown in human SiHa cells in an MTT [3‐(4, 5‐dimethyl‐thiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] cytotoxicity assay. These results indicate that the DEAE–CMC microspheres could be used as safe, promising drug‐delivery systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39890.  相似文献   

17.
Reduced graphene oxide (rGO) sheets were first modified with 2‐hydroxypropyltrimethyl ammonium chloride chitosan (HACC), and these modified rGO sheets (named HACC–rGO) were used as reinforcement materials and introduced to the walls of chitosan (CS) microcapsules. All of the monodisperse microcapsules were conveniently generated by a gas–liquid microfluidic technique. The results of scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis all demonstrate that the HACC–rGO sheets existed and were dispersed in the capsular shell. The HACC–rGO‐reinforced CS microcapsules showed better mechanical strength and better chemical stability with an α‐cyclodextrin solution than the CS microcapsules without HACC–rGO. Importantly, the HACC–rGO‐reinforced CS microcapsules exhibited a slower drug‐release behavior and provide a method for the control of the release rate of drug‐loaded microcapsules. In an in vitro cytotoxicity evaluation by a 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide assay, the Schwann cells still showed good cell viability after they were treated by extracts of the CS/HACC–rGO microcapsules with concentrations ranging from 0.02 to 2000 μg/mL. Therefore, the HACC–rGO‐reinforced CS microcapsules are promising for applications in the fields of drug delivery and controlled release. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44549.  相似文献   

18.
The purpose of this study was to fabricate and evaluate nanoparticles based on β‐conglycinin (7S) and chitosan (CS) to deliver 5‐fluorouracil (5‐FU). The nanoparticles were prepared with a self‐assembly method. Turbidity measurements performed at 600 nm were used to investigate the formation of the nanoparticles as a function of the pH, 7S‐to‐CS mass ratio, and total concentration of 7S and CS. The optimum conditions for the preparation of the nanoparticles were a pH of 5.5, a 7S‐to‐CS mass ratio of 4 : 1, and total concentration of 7S and CS of 9 mg/mL. Under these conditions, the nanoparticles in solution had a high turbidity and good stability. Fourier transform infrared spectroscopy revealed that the nanoparticles were formed mainly through electrostatic interactions between the amine groups (? NH3+) of CS and the carboxyl groups (? COO?) of 7S. Scanning electron microscopy micrographs and dynamic light scattering analysis showed that the nanoparticles had an approximately spherical morphology with a smooth surface, and the mean particle size was about 120 nm with a narrow size distribution. The release of 5‐FU showed an initial burst release followed by a sustained release, and the release was pH‐dependent. The release mechanism of 5‐FU was Fickian diffusion according to the Ritger–Peppas model. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41963.  相似文献   

19.
A series of low‐density polyethylene (LDPE) antibacterial functional plastics were prepared by mechanical blending with commercial chitosan (CS), self‐made water‐soluble chitosan (W‐CS), and microchitosan as antibacterial agents. The effects of the antibacterial agent content on the elongation at break of the obtained plastics were tested, and the bacteriostatic effects against Escherichia coli, Bacillus subtilis, and Proteus species were investigated. The results indicate that the elongation at break of LDPE with antibacterial agent decreased and had a slower decline when the mass ratio of CS to LDPE was greater than 0.5 : 100. The LDPE‐based plastics showed different antibacterial activities against the three experimental strains, and plastics with W‐CS exhibited the best antibacterial activity against B. subtilis. However, the antibacterial content had little effect on the antibacterial ratio. Moreover, 6‐week soil burial tests indicated that the addition of CS caused a decrease in the resistance of LDPE to microbiological deterioration in a natural environment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

20.
The iodine pentoxide is one of the most advanced oxidizers for nanostructured energetic formulations among the thermites due to the highest energy release per volume 25.7 kJ cm−3. The size and shape of iodine pentoxide particles have a strong impact on the pressurization rates during the reaction. Although micro‐sized iodine pentoxide particles are commercially available, nano‐sized particles, which are desired for various nano‐energetic applications, are not available on the market. Conventional wet chemical methods are unable to produce iodine pentoxide nanoparticles due to high solubility in water. In this study, we demonstrate fabrication of iodine pentoxide nano‐rods by high energy mechanical treatment of micro‐sized I2O5 particles. Tuning the energy dose in high‐energy ball milling is allowing to produce I2O5 nano‐rods with diameter of 50–100 nm and length of 300–600 nm. The produced nano‐rods exhibited 10 % smaller decomposition energy compared to the precursor of micro particles. The experiments showed that the nano‐energetic materials prepared with nano‐sized I2O5 rods have pressure discharge value of 43.4 MPa g−1 which is two times higher than using commercial iodine pentoxide particles.  相似文献   

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