We formulated a pH-sensitive chlorhexidine-loaded mesoporous silica nanoparticles (MSN) modified with poly-(lactic-co-glycolic acid) (CHX-loaded/MSN-PLGA) and incorporated into experimental resin-based dentin adhesives at 5 and 10 wt%. Nanocarriers were characterized in terms of morphology, physicochemical features, spectral analyses, drug-release kinetics at varying pH and its effect on dentin-bound proteases was investigated. The modified dentin adhesives were characterized for cytotoxicity, antimicrobial activity, degree of conversion (DC) along with CHX release, micro-tensile bond strength (μTBS) and nano-leakage expression were studied at different pH values and storage time. CHX-loaded/MSN-PLGA nanocarriers exhibited a significant pH-dependent drug release behavior than CHX-loaded/MSN nanocarriers without PLGA modification. The highest percentage of CHX release was seen with 10 wt% CHX-loaded/MSN-PLGA doped adhesive at a pH of 5.0. CHX-loaded/MSN-PLGA modified adhesives exhibited more profound antibiofilm characteristics against S. mutans and more sustained CHX-release which was pH dependent. After 6 months in artificial saliva at varying pH, the 5 wt% CHX-loaded/MSN-PLGA doped adhesive showed excellent bonding under SEM/TEM, higher μTBS, and least nano-leakage expression. The pH-sensitive CHX-loaded/MSN-PLGA could be of crucial advantage for resin-dentin bonding applications especially in reduced pH microenvironment resulting from biofilm formation; and the activation of dentin-bound proteases as a consequence of acid etching and acidic content of bonding resin monomers.

我们配制有聚- （乳酸-修饰的pH敏感的氯己定加载的介孔二氧化硅纳米粒子（MSN）共-乙醇酸）（CHX负载/ MSN-PLGA），并以5和10 wt％的比例掺入实验性树脂基牙本质粘合剂中。研究了纳米载体的形态，理化特性，光谱分析，在不同pH下的药物释放动力学及其对与牙本质结合的蛋白酶的影响。改性的牙本质粘合剂的细胞毒性，抗菌活性，转化率（DC）以及CHX释放，微拉伸键强度（μTBS）和纳米渗漏表达在不同的pH值和储存时间下进行了表征。与未经PLGA修饰的CHX / MSN纳米载体相比，CHX / MSN-PLGA纳米载体表现出显着的pH依赖性药物释放行为。在pH为5.0的情况下，使用10 wt％的CHX负载/ MSN-PLGA掺杂的粘合剂可以看到最高的CHX释放百分比。变形链球菌和更持久的CHX释放取决于pH。在不同pH值的人造唾液中放置6个月后，负载5 wt％CHX / MSN-PLGA的胶粘剂在SEM / TEM下表现出优异的粘合性，具有更高的μTBS，且纳米泄漏最少。pH敏感的CHX负载/ MSN-PLGA对于树脂-牙本质粘合应用可能具有至关重要的优势，尤其是在生物膜形成导致pH降低的微环境方面；酸腐蚀和键合树脂单体的酸性含量导致结合牙本质的蛋白酶活化。