具有Janus结构的多糖基抗菌纳米复合水凝胶用于治疗拔牙窝感染

Polysaccharide-based antibacterial nanocomposite hydrogels with Janus structure for treatment of infected extraction socket

拔牙窝位点保存需要特殊的组织工程支架.在本研究中,我们采用渗透交联的方法开发了一种具有抵抗成纤维细胞入侵、牙槽骨保存和抗菌的多功能Janus结构复合水凝胶.通过将氧化的海藻酸钠溶液渗透到含有羧甲基壳聚糖的高黏性纳米羟基磷灰石悬浮液中来构建水凝胶.通过这个过程制备出的Janus结构水凝胶,其致密、光滑的上表面对成纤维细胞显示出显著的屏障功能,而其疏松、多孔的下表面可以在纳米羟基磷灰石的作用下进行有效的牙槽骨保存,并且在水凝胶中加入了一种抗菌剂甲硝唑,有效抑制了牙周炎相关细菌.其中最优组CAH4M水凝胶对变形链球菌和牙龈卟啉单胞菌的抗菌效率分别为82%和93%,溶血率小于5%,没有明显的细胞毒性.

The socket preservation requires special structures for tissue engineering scaffolds.In this study,we developed a kind of Janus nanocomposite hydrogels with antibacterial property,soft tissue barrier function and bone repairing ability using a penetration cross-linking method.The hydrogels were constructed by permeating oxidized sodium alginate solution into a highly viscous nano-hydroxyapatite-contained carboxymethyl chitosan suspension.Through this process,the Janus structure was fabricated.The dense,smooth top-surface showed a significant barrier function against fibroblast cells,while its loose,porous bottomsurface could support bone regeneration with nano hydroxyapatite.And in order to inhibit periodontitis-related bacteria,an antibacterial agent,metronidazole,was combined into the hydrogels.The CAH4M hydrogel showed antibacterial efficiencies of 82%against S.mutans and 93%against P.gingivalis.The hemolysis ratio was less than 5%,and there was no evident cytotoxicity,demonstrating the good biocompatibility.The in vivo anti-infection and bone repairing properties of the hydrogels were verified by a rat model of infected extraction socket.Based on the above results,this study provided a promising strategy to prepare tissue engineering scaffolds that meet clinical requirements for socket preservation and prevention of infection.