大尺寸羟基磷灰石微米管有序结构/高分子复合材料

The common disease caries usually needs to be treated by restoration using the dental resins. However, the conventional dental materials cannot meet the increasing requirements for the high antimicrobial, mechanical and biomimetic properties. This proposal presents a new composite material used for dental restoration which is constructed by the highly ordered hydroxyapatite microtube material with large size and dental resin. To prepare the composite material, the highly ordered hydroxyapatite microtube material doped by antimicrobial metal.ions is prepared by a precursor transformation in the solvothermal environment; then the pores of the hydroxyapatite material is filled with resin monomers after surface modification, and induce the polymerization; after that, a dental enamel-like hydroxyapatite layer is formed on the upper surface of the composite in the simulated body fluid or simulated saliva by biomineralization with the induction of the ordered structure of the hydroxyapatite material to get the final product. The capability of dental restoration is investigated in vitro and in vivo. This project will focus on studying the science problems involved, including the growth mechanism of the ordered structure, the effect of the surface.modification on the interfacial binding, the antimicrobial effect of the doped metal ions, the influence of the biomimetic hydroxyapatite layer on the properties of the composites, and the mechanism of the property enhancement by compositing.

龋齿是一种高发的口腔疾病，其治疗常需要牙科树脂进行修复，然而传统的牙科树脂材料抗菌性差、力学性能不高、不具有仿生结构，不能满足人类越来越高的要求。本项目提出构建一种以大尺寸（毫米级）羟基磷灰石微米管有序结构材料和牙科树脂的有机无机复合材料，以应用于牙齿修复。具体先通过溶剂热辅助低熔点疏水性钙源前驱体转化法制备大尺寸羟基磷灰石微米管有序结构材料，同时掺杂抗菌金属离子；然后经表面修饰后与树脂单体混合，并引发其聚合；之后利用微米管有序结构诱导在模拟唾液或模拟体液中矿化一层类牙釉质羟基磷灰石结构，从而制备出大尺寸羟基磷灰石微米管有序结构/高分子复合材料。通过体内外实验，研究其牙齿修复能力。深入研究该复合材料构建所涉及的重要科学问题，包括有序结构生长机理、表面改性对复合材料界面结合力的影响规律、掺杂的抗菌金属离子抵抗口腔细菌的作用、仿生矿化层对材料整体性能的影响、复合材料性能增强的机制等。

有机—无机纳米复合材料在牙齿和骨骼等硬组织修复领域有非常广阔的应用前景。本项目参照牙釉质内部高度有序的微观结构特征，以一维的羟基磷灰石微纳米管/线和生物相容性有机高分子为基本构建原料，设计和构建结构上高度有序的有机无机纳米复合材料。在具体实施过程中首先发展和优化了羟基磷灰石微纳米管线及其有序结构的制备方法；然后在此基础上通过不同的方法构建了多种有机无机复合有序结构材料。其尺寸可控、结构可调、具有生物安全性和优异的力学性能。其中所制备的一维有序仿牙釉质结构材料可以较精确地模仿牙釉质的结构特征，并显著增强牙科树脂的力学性能；所制备的高强高韧有序层状结构材料，结合了牙釉质和骨组织的结构特征，弯曲强度超过318 MPa, 韧性达到4.5 MPa m1/2，具有非常优异的力学性能和应用前景。此外，通过对材料的结构、界面性质、性能等研究，认识了该有机无机复合材料中的力学增强因素，阐明到了界面作用、有序结构、纤维侨联等作用对材料增强增韧的机制。.该项目的相关研究成果，已在Advanced Materials、ACS Nano、ACS Applied Materials and Interfaces、Chemical Engineering Journal、Chemistry – A European Journal等学术期刊上发表标注本项目资助的论文 10 篇，并帮助培养3名博士研究生获得学位，另有2名在继续攻读。因此，本项目取得的成果已经完全达到并优于项目考核或预定研究指标的要求。