School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, PR China.
Biomater Sci. 2018 Feb 27;6(3):596-603. doi: 10.1039/c7bm00764g.
Lyotropic liquid crystals (LLC) have received increasing attention as a drug delivery system. In this study, a novel intra-canal disinfectant based on the glycerol monooleate (GMO) LLC precursor incorporation with chlorhexidine (CHX) and silver nanoparticles (Ag-NPs) was designed and evaluated. The LLC precursor with excellent fluidity was able to penetrate deeply into the complex tiny collateral branch root canals. The transformation of cubic LLC in root canals upon coming into contact with water provided long-lasting disinfection against multidrug-resistant bacteria to avoid the endodontic reinfection and follow-up visits. The GMO-ethanol-water (48% : 12% : 40%, w/w) formulation containing 0.5% CHX and 0.02% Ag-NPs was selected for further studies. The low viscosity of the precursor presented excellent injectability and flowabilities. From the in vitro release test, the release behaviours were found to be influenced by CHX and Ag-NP contents, allowing the optimized precursor to obtain a 28-day release profile. The CHX-Ag-NP containing LLC precursor exhibited an excellent and sustained sterilization effect on Enterococcus faecalis for more than one month with a bacterial inactivation rate of ≥98.5%, which was far more than the minimum clinical requirement (7 days). Furthermore, no in vitro toxicity was observed in the cytotoxicity evaluation. The CHX-Ag-NP containing LLC precursor was proved to be a promising intra-canal disinfectant in our study.
溶致液晶（LLC）作为一种药物传递系统受到了越来越多的关注。在这项研究中，设计并评估了一种新型的基于甘油单油酸酯（GMO）LLC 前体与洗必泰（CHX）和银纳米粒子（Ag-NPs）结合的根管内消毒剂。具有优异流动性的 LLC 前体能够深入穿透复杂的细小侧支根管。立方 LLC 在接触水后在根管内的转化提供了针对多药耐药菌的持久消毒，以避免根管内再感染和随访。选择含有 0.5% CHX 和 0.02% Ag-NPs 的 GMO-乙醇-水（48%：12%：40%，w/w）配方进行进一步研究。前体的低粘度表现出优异的可注射性和流动性。从体外释放试验中可以发现，释放行为受到 CHX 和 Ag-NP 含量的影响，允许优化的前体获得 28 天的释放曲线。含有 CHX-Ag-NP 的 LLC 前体对粪肠球菌表现出优异且持续的杀菌效果，超过一个月，细菌灭活率≥98.5%，远远超过最低临床要求（7 天）。此外，在细胞毒性评估中没有观察到体外毒性。含有 CHX-Ag-NP 的 LLC 前体在我们的研究中被证明是一种有前途的根管内消毒剂。
