氧化锆基微量元素共掺杂羟基磷灰石增韧涂层研究

Zirconia Reinforced Trace Element Co-doped Hydroxyapatite Coating

氧化锆陶瓷具有良好的力学性能和生物相容性,是一种应用前景广阔的硬组织植入体材料。为促进植入体与骨组织形成稳定的骨结合,本研究利用等离子喷涂制备了氧化锆增韧的锶、硅、氟微量掺杂羟基磷灰石(ZrO2-DHA)涂层,对涂层物相、形貌以及力学性能和体外生物学性能进行了研究。结果表明,锶、硅、氟的共掺杂通过成骨分化的信号转导通路提高了羟基磷灰石涂层对成骨细胞的黏附和分化等生物学性能;不同复合组分的ZrO2-DHA涂层均不同程度地促进了小鼠成骨前体细胞的细胞活力和成骨分化相关基因的表达。在细胞培养的第7 d,DHA含量为70%的ZrO2-DHA涂层(7DHA)Alp和Col-I的相对表达量分别是对照组的约2.8倍和2.3倍;ZrO2-DHA涂层的力学性能随氧化锆组分的增加而增强,DHA涂层和7DHA涂层的硬度和结合强度分别为250.8、313 HV和25.1、31.8 MPa;7DHA涂层中的交织网络结构,对残余热应力、压应力和拉伸力的承受能力较DHA涂层明显提升,满足植入体应用需求。

Zirconia is a kind of prospective hard tissue implant materials,which possesses superior mechanical properties and excellent biocompatibilities.To promote the stable osseointegration between Zirconia implants and tissue,zirconia-toughened trace Sr-,Si-and F-co-doped hydroxyapatite(ZrO2-DHA)was coated by plasma spraying on zirconia.The phase composition and structure of coatings were characterized,and the mechanical properties and in vitro biological properties were investigated.The results show that co-doping of trace Sr,Si and F enhances the biological properties of coatings on adhesion and differentiation of osteoblasts through the signal transduction pathway of osteogenic differentiation.All of ZrO2-DHA coatings promote the cell viability and gene expression in osteogenic differentiation of MC3T3-E1.On the 7th day of cell culture,the relative expression levels of Alp and Col-I in the ZrO2-DHA coating containing 70%DHA(7DHA)were about 2.8 times and 2.3 times higher than those in the ZrO2 substrate group,respectively.Mechanical properties of ZrO2-DHA coatings are improved with the increment of zirconia ratio.Hardness of DHA coating and 7DHA coating are 250.8 and 313 HV respectively and their bond strength are 25.1 and 31.8 MPa,respectively.7DHA coatings with network structure possess both excellent mechanical and biological per formance for the implant coating application.