不同表面官能团和化学组成共聚物微球的表面生物矿化研究

采用具有不同共聚物组成和端基官能团的聚己内酯-b-聚乙二醇共聚物(PCL-b-PEG),通过双乳液溶剂挥发法制备了一系列具有不同表面性质的生物降解高分子微球.采用生物模拟矿化的方法以磷灰石修饰微球表面.进一步通过扫描电镜、热重分析仪、X-射线衍射仪和光电子能谱仪对微球表面磷灰石的形貌、含量、结构和组成进行了分析.研究了微球表面亲水性、粗糙度、官能团以及矿化时间对于磷灰石形成的影响.最终实验结果表明,随着共聚物中PEG含量增加,微球表面粗糙度和亲水性增加,因此微球表面磷灰石含量增加.同时微球表面官能团以及矿化时间的不同也会对磷灰石的形成和分布产生明显影响.

BIOMINERALIZATION ON COPOLYMERIC MICROSPHERES SURFACE WITH DIFFERENT FUNCTIONAL GROUPS AND COMPOSITION

PCL-b-PEG with different composition and functional groups were used to prepare microspheres with different surface properties by means of the double emulsion solvent evaporation method.Then,the biomineralization of microspheres was performed in the 1.5 simulated body fluid(1.5SBF).The effects of the hydrophilicity,roughness and functional groups of microsphere surface on the formation of apatite were studied.It was found that the higher molar ratio of PEG to PCL leads to rougher and more hydrophilic microsphere surface,which results in the formation of more apatite.The functional groups were found to have great influence on the formation and distribution of apatite on the surface of microspheres.Apatite was distributed homogeneously on the surface of PCL20K-b-PEG1K-COOH microspheres.Moreover,the amount of apatite on microsphere surface increased with the mineralization time.The biomineralization had an initial period of ca.4 days for apatite nucleation,followed by normal gradual growth.The results of this work indicate that the surface properties of microspheres such as hydrophilicity,roughness and functional groups as well as the biomineralizaiton time could be used to control the apatite formation on microsphere surface.These results are expected to be used in the construction of tissue engineering scaffolds.