利用二醛木聚糖一锅法制备纳米银抗菌水凝胶

利用二醛木聚糖(DAX)可与羧甲基壳聚糖(CMCS)以及银氨溶液同时反应的特性,即DAX的醛基与CMCS的氨基发生席夫碱反应形成亚胺键,同时,DAX含有的大量醛基与银氨溶液发生银镜反应,在室温条件下很快地还原出银纳米粒子(SNPs),一锅法制备出了具有优异抗菌性能的羧甲基壳聚糖-纳米银抗菌水凝胶。加入生物相容性良好的聚乙烯醇(PVA)并通过冻融法形成了与CMCS互穿的双网络结构,进一步提高了水凝胶的结构稳定性。采用FTIR、热重、TEM、XRD和SEM对DAX,SNPs和水凝胶的形貌、结构进行了表征。结果表明DAX在整个反应中起到了十分有效的双功能作用,成功的与CMCS和PVA发生反应,共同构成了双网络结构的水凝胶,从而提高了水凝胶的力学性能。同时,DAX将银氨溶液中的SNPs还原出来,且粒径在20-80 nm之间,具有较好的分散性,从而显著提高了水凝胶的抗菌性。本文中所制备的水凝胶具有伤口敷料方面的应用潜力。

One-pot preparation of nanosilver antibacterial hydrogels using dialdehyde xylan

Taking advantage of the feature that dialdehyde xylan (DAX) can react with carboxymethyl chitosan (CMCS) and silver ammonia solution at the same time, that is, the aldehyde group of DAX reacts with the amino group of CMCS to form an imine bond, and at the same time, A large number of aldehyde groups contained in DAX undergo a silver mirror reaction with silver ammonia solution, and silver nanoparticles (SNPs) are quickly reduced at room temperature. Carboxymethyl chitosan-nanoparticles with excellent antibacterial properties were prepared by one-pot method. Silver antibacterial hydrogel. Polyvinyl alcohol (PVA) with good biocompatibility was added and a double network structure interpenetrating with CMCS was formed by freeze-thaw method, which further improved the structural stability of the hydrogel. The morphology and structure of DAX, SNPs and hydrogels were characterized by FTIR, thermogravimetric, TEM, XRD and SEM. The results showed that DAX played a very effective bifunctional role in the whole reaction, and successfully reacted with CMCS and PVA to form a hydrogel with a double network structure, thereby improving the mechanical properties of the hydrogel. At the same time, DAX reduces the SNPs in the silver ammonia solution, and the particle size is between 20-80 nm, which has good dispersibility, thereby significantly improving the antibacterial properties of the hydrogel. The hydrogels prepared herein have potential applications in wound dressings.