铜锶二元掺杂硅酸钙涂层改性钛合金的促成骨和抗菌效应

Osteogenic and antibacterial effects of titanium alloy modified with copper-strontium binary doped calcium silicate coating

背景:钛合金作为骨科植入物时缺乏生物活性,可导致种植体松动和假体周围感染,因此,研究一种兼顾促成骨和抗感染复合功能的钛合金表面改性方法具有重要意义。目的:研究铜、锶二元掺杂硅酸钙复合涂层改性钛合金的理化性质,评估其促成骨和抗菌方面的潜能。方法:采用球磨、造粒方法制备含有氧化铜、氧化锶及硅酸钙的复合粉末,采用大气等离子喷涂技术在钛合金(Ti6Al4V)表面制备铜锶二元掺杂硅酸钙复合涂层,对复合涂层进行表征。将钛合金浸提液、硅酸钙涂层改性钛合金浸提液、铜掺杂硅酸钙复合涂层改性钛合金浸提液、铜锶二元掺杂硅酸钙复合涂层改性钛合金浸提液分别与MC3T3-E1细胞共培养,检测材料的生物安全性与促成骨性能。将金黄色葡萄球菌(或大肠埃希菌)分别与钛合金、硅酸钙涂层改性钛合金、铜掺杂硅酸钙复合涂层改性钛合金、铜锶二元掺杂硅酸钙复合涂层改性钛合金共培养,扫描电镜、平板计数法检测材料的体外抗菌性能。结果与结论:(1)扫描电子显微镜下可见铜锶二元掺杂硅酸钙复合涂层粗糙表面存在大量的纳米结构,该复合涂层成功喷涂在钛合金表面,在体外可缓释Sr^(2+)和Cu^(2+),并且Sr^(2+)的释放浓度大于Cu^(2+);(2)CCK-8和细胞活死染色结果显示,铜掺杂硅酸钙复合涂层改性钛合金具有一定的细胞毒性,硅酸钙涂层与铜锶二元掺杂硅酸钙复合涂层改性钛合金具有良好的生物相容性;碱性磷酸酶与茜素红染色结果显示,相较于钛合金、硅酸钙涂层改性钛合金,铜锶二元掺杂硅酸钙复合涂层改性钛合金表现出更优的促成骨性能;(3)扫描电镜观察、细菌涂布和细菌计数法结果表明,相较于钛合金、硅酸钙涂层改性钛合金,铜掺杂硅酸钙复合涂层与铜锶二元掺杂硅酸钙复合涂层改性钛合金能有效抑制金黄色葡萄球菌和大肠埃希菌的生长,表现出抗菌潜能;(4)结果表明,铜锶二元掺杂硅酸钙复合涂层改性钛片具备良好的生物相容性、促成骨性能与抗菌性能。

BACKGROUND:Titanium alloys lack biological activity when used as orthopedic implants,which can lead to implant loosening and periprosthetic infection.Therefore,it is of great significance to study a titanium alloy surface modification method that combines osteogenic and anti-infection functions.OBJECTIVE:To study the physical and chemical properties of titanium alloy modified with copper and strontium binary doped calcium silicate composite coating,and to evaluate its bone-promoting and antibacterial potential.METHODS:Ball milling and granulation methods were used to prepare composite powder containing copper oxide(CuO),strontium oxide(SrO),and calcium silicate(CS).A copper-strontium binary doped calcium silicate composite coating was prepared on the surface of titanium alloy(Ti6Al4V)through atmospheric plasma spraying technology.The composite coating was characterized.The titanium alloy extract,calcium silicate coating modified titanium alloy extract,copper-doped calcium silicate composite coating modified titanium alloy extract,and copper-strontium binary doped calcium silicate composite coating modified titanium alloy extract were co-cultured with MC3T3-E1 cells to detect the biosafety and osteogenic properties of the materials.Staphylococcus aureus(or Escherichia coli)were co-cultured with titanium alloy,calcium silicate coating modified titanium alloy,copper-doped calcium silicate composite coating modified titanium alloy,and copper-strontium binary doped calcium silicate composite coating modified titanium alloy.The in vitro antibacterial properties of the materials were detected by scanning electron microscopy and plate counting method.RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that a large number of nanostructures existed on the rough surface of the copper-strontium binary doped calcium silicate composite coating.The composite coating was successfully sprayed on the surface of titanium alloy.The composite coating could slowly release Sr^(2+)and Cu^(2+)in vitro.The release concentration of Sr^(2+)was greater than that of Cu^(2+).(2)CCK-8 assay and cell live/dead staining results showed that the copper-doped calcium silicate composite coating modified titanium alloy had certain cytotoxicity.The calcium silicate coating and the copper-strontium binary doped calcium silicate composite coating modified titanium alloy had good biocompatibility.Alkaline phosphatase and alizarin red staining results showed that compared with titanium alloy and calcium silicate coating modified titanium alloy,copper strontium binary doped calcium silicate composite coating modified titanium alloy showed better osteogenic properties.(3)The results of scanning electron microscopy,bacterial coating,and bacterial counting method showed that compared with titanium alloy and calcium silicate coating modified titanium alloy,copper-doped calcium silicate composite coating and copper strontium binary doped calcium silicate composite coating modified titanium alloy can effectively inhibit the growth of Staphylococcus aureus and Escherichia coli,showing antibacterial potential.(4)The results indicate that copper strontium binary doped calcium silicate composite coating modified titanium sheet has good biocompatibility,osteogenic and antibacterial properties.