聚醚醚酮表面可降解复合生物涂层的制备及增强骨生物活性的机制研究

Polyetheretherketone (PEEK) exhibits stable chemical properties, good biocompatibility and appropriate biomechanical properties those are close to human cortical bone, but it is lack of bioactivity and can't achieve efficient osseointegration after being implanted. Therefore, modifying PEEK to improve its bioactivity is of great clinical value. Surface coating can improve the bioactivity of PEEK to a certain extent, but the bonding strength between the coating and substrate is often relatively weak. In this study, a melt extrusion technique will be used to make a porous structure on the PEEK surface, and then a calcium silicate/β-tricalcium phosphate (CS/TCP) composite will be coated onto the porous PEEK surface by a cold gas spray technology to prepare a degradable and bioactive composite coating. The surface characterization, bonding strength of the coating, biomechanical properties and in vitro degradation will be evaluated. Importantly, the apatite formation ability, in vitro adhesion, proliferation, spread and osteogenic differentiation of osteoblasts, and in vivo degradation and osseointegration will be investigated. Furthermore, the possible mechanism of the enhanced osteogenesis of the biocoating will be investigated from the perspective of macrophages. We suppose that as the coating layer being degraded new bone tissues will replace the coating to grow into the pores to achieve highly efficient osseointegration. It is believed that this novel PEEK coating material will be applied as material of interbody fusion cage or artificial joint prosthesis in the orthopedic clinic.

聚醚醚酮（PEEK）具有稳定的化学性质、良好的生物相容性和与人体皮质骨接近的生物力学特性，但它缺乏生物活性，植入体内后难以达到高效骨整合。因此，对PEEK改性以提高其生物活性具有重要的临床应用价值。表面涂层可提高PEEK的生物活性，但涂层和基材的结合强度往往不够。本研究拟通过熔融挤出技术使PEEK表面形成微米级多孔结构，然后利用冷气喷涂技术将硅酸钙/β-磷酸三钙（CS/TCP）复合物涂层至多孔PEEK表面，制备PEEK表面可降解复合生物涂层材料，探讨材料的表面特性、涂层结合强度、生物力学、体外降解，并重点探讨材料的磷灰石形成能力、体外成骨细胞粘附、增殖、铺展、成骨分化及体内降解和骨整合。另外，从巨噬细胞的角度探讨涂层材料可能的促成骨机制。我们设想随着表面涂层的降解，新生骨组织可长入多孔结构内部，最终达到高效骨整合。此新型PEEK涂层材料可作为椎间融合器和人工关节假体材料应用于骨科临床。

聚醚醚酮（PEEK）具有稳定的化学性质、良好的生物相容性和合适的生物力学强度，但它缺乏生物活性，表面涂层可提高PEEK的生物活性。浓硫酸浸泡磺化处理可使PEEK表面形成3D多孔立体结构，但PEEK磺化处理的具体实验方法并不确切。本研究首先通过磺化处理使PEEK表面形成多孔结构，然后利用冷喷涂技术将硅酸钙（CS）/β-磷酸三钙（TCP）复合物涂层至磺化PEEK表面，以制备3D多孔PEEK表面可降解复合生物涂层材料。我们通过实验比较发现浓硫酸浸泡的最佳实验方案为：磁力搅拌下浸泡5min，丙酮水洗、水热处理、氢氧化钠浸泡三种后处理方式皆可有效去除表面残留硫酸。另外，通过球磨处理以避免涂层粉末发生团聚，通过调整冷喷涂设备的各种喷涂参数，我们在PEEK表面喷涂CS或CS/TCP制备CS/PEEK和CS-TCP/PEEK涂层材料，在磺化PEEK（SPEEK）表面喷涂CS或CS/TCP制备CS/SPEEK和CS-TCP/SPEEK涂层材料，大体形貌、扫描电镜和能谱分析都显示涂层成功。前期的细胞实验证实，CS或CS/TCP涂层可以明显促进PEEK或SPEEK表面MC3T3-E1细胞的粘附、增殖、铺展和成骨分化。