一氧化氮释放壳聚糖复合水凝胶的制备及其抗菌性能评估

Preparation of a nitric oxide-releasing chitosan-based composite hydrogel and assessment of its antimicrobial properties

为了获得能够抵御细菌感染的伤口敷料,将原儿茶醛(PA)和氯化铁配位形成PA/铁离子螯合物(PA/Fe),并通过希夫碱反应与羧甲基壳聚糖(CMCS)交联形成水凝胶,在水凝胶中负载一氧化氮(NO)供体分子N,N′-二仲丁基-N,N′-二亚硝基-1,4-苯二胺(BNN6),得到BNN6@CMCS-PA/Fe复合水凝胶;对BNN6@CMCS-PA/Fe的结构和性能进行表征,评估其生物安全性及体外抗菌性能。结果表明:该水凝胶具有优良的力学性能和高溶胀率(1169%),能够黏附于多种材料表面,并具有自愈合能力和生物相容性;在405nm光照下,水凝胶中的BNN6分解释放NO的速率达到了7.2μmol/(L·h),并且水凝胶在808nm光照下表现出光热效应,10min平均升温36.5℃;该水凝胶对金黄色葡萄球菌和大肠杆菌的生长表现出了显著的抑制效果,其中通过NO对细菌的抑菌率均超过93%,通过光热效应的抑菌率均超过99%。该研究为气体释放敷料应用于促进细菌感染伤口的愈合提供了理论依据。

To obtain a wound dressing resistant to bacterial infection,protocatechualdehyde(PA)and iron chloride were coordinated to form iron PA/ferric ion chelate(PA/Fe).Then PA/Fe was crosslinked with carboxymethyl chitosan(CMCS)by Schiff base to form a hydrogel,which was subsequently loaded with a nitric oxide(NO)donor N,N′-di-sec-butyl-N,N′-dinitroso-1,4-phenylenediamine(BNN6)to obtain a BNN6@CMCS-PA/Fe composite hydrogel.The structure and properties of the BNN6@CMCS-PA/Fe composite hydrogel were characterized,and its biosafety and in vitro antibacterial performance were analyzed.The results showed that the hydrogel had excellent mechanical properties,a high swelling ratio(1169%),adhesion to various materials,self-healing ability and excellent biocompatibility.Under 405nm light irradiation,the rate of NO release from BNN6in the hydrogel reached 7.2μmol/(L·h),and the hydrogel exhibited photothermal effect under 808nm light irradiation,with an average temperature increase of 36.5℃in 10minutes.At the same time,the hydrogel showed significant inhibitory effects on the growth of Staphylococcus aureus and Escherichia coli,with antibacterial rates exceeding 93%for bacteria inhibited by NO and over 99%for bacteria inhibited by photothermal effects.To sum up,this study provides theoretical basis for the application of gas-releasing dressing in promoting the healing of bacterial infected wounds.