聚合物涂层调控生物医用材料的降解行为

A successful tissue regeneration using biodegradable material requires a degradation rate of the biomedical materials which matches the formation rate of neotissue. Therefore, it is very important to figure out effective ways to regulate the degradation profile of biomedical materials; if the degradation profile can be tuned by a surface change of a material given a popular matrix, the principle and the corresponding technique will be of high impact. Water molecules play an important role in degradation of many biomedical materials. The applicant anticipates to regulate degradation profile of biodegradable materials through controlling the penetration process of water into matrix by surface modification. Based on such an idea, this research project suggests a water-resistant coating composed of block copolymer with a water-resistant block and a biodegradable block. The block copolymers are desired to form a microphase-separated structure, in which the water-resistant blocks constitute the continuous phase and the degradable blocks constitute the cylindrical separated phase. The block copolymer coating could then be used to control the penetration process of water into the matrix and thus the degradability profile of the whole material including both the matrix and the coating. The technology developed in this research project might offer a way to design and regulate the degradation profile of biomedical materials.

生物医用可降解材料的降解速率与体内组织的再生速率相匹配对最终修复效果至关重要，因此如何有效地调控材料的降解行为就成为一个关键的基础科学问题；若能在不改变基底材料的前提下调控材料整体的降解动力学过程则特别有意义。部分生物医用材料的降解与水分子的参与密不可分，本项目打算通过设计改变材料表面性质以程序式地调节水分子渗透进入材料基体的过程、从而调控材料整体的降解进程。项目拟合成并制备一类隔水涂层，相应高分子选择具备隔水性能的高分子和可降解的高分子所组成的嵌段共聚物，涂层具有以隔水链段为连续相、降解链段为柱状分散相的微相分离结构。通过发挥连续相的隔水性能、分散相的逐步降解以控制水分子穿透涂层的程度，从而调节材料基体的降解进程。本项目有望为生物医用可降解材料的设计和降解行为的调控提供新的思路。

调控生物医用可降解材料的降解行为不仅是一个关键的基础科学问题，也具有重要的临床应用价值。本项目提出了通过改变材料表面性质调控材料整体降解进程的想法，由此设计了聚合物隔水涂层程序式地调控水分子渗透进入材料基体的技术路线。..项目对聚合物隔水涂层作了以下研究：.（1）设计并合成了聚酯-聚二甲基硅氧烷-聚酯嵌段共聚物以及嵌段共聚物大单体，发现选用碳酸铯作为缚酸剂可以提高嵌段共聚物大单体的双键端基比例以及批次间稳定性；.（2）基于合成的嵌段共聚物大单体，开发了旋涂或超声喷涂结合光交联反应的涂层制备工艺，由此可以制备得到具有较好弹性的隔水涂层；.（3）对隔水涂层的隔水性能进行测试，测试结果证实了隔水涂层的引入可以一定程度减缓材料基体的降解进程。..项目研究成果对生物医用可降解材料的降解调控提供了新的思路，为新型生物医用材料的设计提供了一定指导。