纳米二氧化硅牙菌斑中递载氟化物用于防龋齿研究

Nanocarriers provide possibility of targeted delivery and cooperative treatment, thus improve the drug efficiency, reduce adverse effects and increase the curative rate. The weak penetrability and low retention induce the decreased bioavailability and high toxic effects of caries-preventive drug, such as fluoride. Proper surface modification and suitable size can enhance the penetrability of nanoparticle in dental plaque and make it as applicable nanocarrier of anticariogenic drug. Silica nanoparticle is approved by Food and Drug Administration in USA, and has been used widely as additives in medicine and food, which make them perfect nanocarrier for delivering drug into dental plaque. Calcium phosphate is biocompatible. They can be biodegradable around pH 5, similar pH of demineralization of dental enamel, which make them potential pore-sealing reagent to prevent the undesired leaking and attain smart release of loaded drug. Thus they can decrease the adverse effect of caries-preventing drug. In this project, fluoride is planned to be delivered into dental plaque by silica nanocarrier with proper size and surface modification, and make them release at suitable dental surface and appropriate pH. The resulted low dose and high cure efficiency has the vital significance in increasing the efficiency and safety of fluoride application. Enhancing the fluoride penetration in dental plaque by silica nanopaticles has not been reported yet.

纳米技术为靶向协同给药、提高药效和降低副作用，提高疾病治愈率提供了条件。防龋药物氟化物在牙菌斑中的低渗透和低滞留导致了其生物利用率低、副作用大的问题。恰当表面修饰和合适尺寸的纳米材料，可以作为载体增加氟化物在牙菌斑中的渗透。二氧化硅纳米材料是FDA许可的纳米材料，目前已被广泛应用于食品和医药领域，可作防龋齿药物的理想载体。磷酸钙是可生物降解的生物相容性材料，在pH 5左右溶解，与牙菌斑下釉质脱矿的临界pH值相近。以其为堵孔剂可以实现防龋药物的智能释放。本课题拟借助合适尺寸和表面修饰的纳米二氧化硅载体携带氟化物进入牙菌斑深层，并在pH下降时释放发挥抗龋作用。从而收到用氟量小，防龋功效高的效果，对于高效用氟和安全用氟具有重要的意义。使用纳米二氧化硅载体增加氟在菌斑中的渗透，更好地发挥其抗龋效能的研究，在国际上尚属空白。

本课题，我们制备了具有龋齿防治功能的纳米药物，该纳米粒子在菌斑中能深度渗透，并且在菌斑中能高度滞留，最重要的是药物具有按需响应释放特性，且释放效率可以得到保障。该纳米药物是以FDA批准的二氧化硅纳米粒子为载体制备，所涉及的制备工艺绿色，且可放大，所涉及的制剂均已被广泛应用于牙膏中。因此，所得的纳米药物制剂有望直接作为功能成分添加至漱口水、牙膏口香糖等口腔卫生用品中，而实现应用转化。