磷酸钙基引导骨组织再生材料及其对成骨分化的影响研究

This proposal is targeting at developing calcium phosphate (CaP) -based biomaterials for guided bone regeneration. Techniques including electrospinning, sol-gel method and biomineralization are involved in preparing two kinds of commonly used calcium phosphate-based biomaterials, i.e CaP ceramic nanofibers and inorganic-organic composite nanofibers. The former is produced by using electrospinning in combination with sol-gel method, while the latter is produced by using polymer electrospinning followed by biomineralization.The chemical compositions, crystal structures, morphologies of the above mentioned CaP materials, which are prepared from different parameters, are quite different. Therefore, they would result in different dissolution and re-biomineralization behaviors in cell culture medium, which would cause the chemical balance of the medium changing accordingly.The key scientific issue here is that how would these interactions and changes affect the bone-related cells behaviors, especially on osteodifferentiation? The mechanism behind the relationship is so vital in developing and desiging new guided bone regeneration biomaterial, that it is necessary to carry out the research on solution-mediated reaction and ion-interaction between CaP-based biomaterials and cell culture mediums, as well as their relationships with cell behaviors. Ideally, the present study intends: (1) to correlate the changes of calcium and phosphate ions concentrations in medium, which are resulted from the solution-mediated reaction of CaP compounds, with cell biological behaviors; (2) to clarify the effects of chemical and physical changes in materials, which are resulted from ion-interaction, on cells biological behaviors; and (3) with all these studies, to make the outcomes more reasonable by avoiding extrapolation or universalization. By establishing the correlation between the preparation of CaP-based materials and the cell biological properties, it will provide valuable references for developing guided bone regeneration biomaterials.

以发展仿生引导骨组织再生修复材料为目标，基于静电纺丝、溶胶-凝胶和生物矿化几种制备技术，采用溶胶-凝胶法结合静电纺丝制备磷酸钙陶瓷纳米纤维支架，采用静电纺丝结合SBF生物矿化制备有机-无机纳米复合纤维支架；针对磷酸钙陶瓷纳米纤维因Ca/P比、制备参数、离子掺杂等引起的生物可降解性、晶型、化学组成变化，针对因SBF配方和矿化条件改变所引起矿化沉积层化学组成、晶型差异性，重点考察这两类磷酸钙基材料与细胞培养介质的差异性，及由此所引起的磷酸钙材料溶解-再矿化反应导致培养介质中的化学平衡发生变化，由此对骨细胞和BMSCs的活性及分化性能产生重大影响的基本科学问题，开展磷酸钙基纳米纤维支架材料与细胞培养介质之间的表面反应和离子相互作用及其与成骨相关细胞分化行为之间的关联研究，从而建立起磷酸钙基骨组织工程支架材料制备与细胞生物学行为之间的定量关联，为发展仿生引导骨再生修复材料提供确切的理论和实验参考。

本项目是以发展引导（骨）组织再生修复材料为目标，采用静电纺丝结合SBF生物矿化制备了有机-无机纳米复合纤维支架，采用溶胶-凝胶法结合静电纺丝和高温烧结制备了生物活性陶瓷纳米纤维，同时拓展制备了生物活性玻璃修饰的碳纳米纤维（CNF/BG），并针对因SBF配方和矿化条件改变所引起的矿化沉积层化学组成、晶型的差异性，针对陶瓷纳米纤维因投料比、制备参数、离子掺杂等所引起的降解性、晶型、化学组成的变化，重点研究了这些材料的溶解-再矿化，开展了它们与细胞培养介质间的相互作用及其对BMSCs增殖和成骨分化的调控研究，对建立无机或有机/无机骨组织工程支架材料与细胞生物学行为之间的定量关联提供了较为确切的理论和实验依据。具体研究内容包括：① SBF生物矿化机制的研究：通过在SBF中引入不同氨基酸，研究了HA成核生长过程，及其在聚乳酸/明胶复合（PG）纳米纤维上的沉积；通过以碳纳米管为基础材料，在其表面接枝含有不同官能团（聚丙烯酸、聚甲基丙烯酸羟乙酯、聚丙烯酰胺）高分子，研究了材料表面特性与SBF矿化成核、生长的关联机制；② 以PG纳米纤维为基础材料，开展了矿化产物与离子溶出、细胞生物学行为的关联研究：通过控制矿化沉积的时间，改变纤维膜上矿化沉积物的组成、晶型、沉积量等参数，研究了离子溶出、再矿化沉积等行为，对BMSCs和MC3T3-E1成骨细胞增殖和成骨分化行为的调控机制；通过提高PG纳米纤维促进矿化生长的能力，以细胞培养基为矿化介质，研究了矿化沉积与BMSCs增殖和成骨分化行为的定量关联；③ 制备了单/复相、离子掺杂的磷酸钙陶瓷纤维和（离子掺杂的）硅酸钙陶瓷纤维，开展了离子溶出、生物矿化、生物相容性、细胞相容性和促成骨分化的研究；在此基础上，还制备系列CNF/BG复合纤维，考察了烧结温度/时间、BG组成等参数对离子溶出、生物矿化和细胞行为的影响规律；④ 将无机磷酸根和可溶性氨基酸酯取代聚膦腈降解产物引入到培养基中，对比研究了磷酸根对BMSCs增殖和成骨分化的影响。