Ti-Ag 纳米管/HA 复合涂层的抗菌性能及生物相容性的基础研究

Although Titanium (Ti) and its alloys are widely used clinically, they have some defects such as long-term antibacterial properties (inhibit biofilm formation and prevent implant associated infection) and well biocompatibility in vivo (osseointegrity). The nanotubes assay was fabricated on the surface of the Ti-Ag alloy by anodizing technology and the HA was coated on the surface of Ti/Ag nanotube in simulated body fluid (SBF). Ti-Ag nanotube/HA surface will give some advantages; such as 1) The reliable release and long-term antibacterial ability due to sustained release of Ag ions. 2) The nanotubes which were fabricated on Ti-Ag alloy can promote bone activity. 3) The nanotubular surface can reduce bacteria adhesion. In this study, the surface of nano-structured Ti-Ag/ HA is studied by scanning electron microscopy, the Ag ion release kinetics was studied in animal models to evaluate the Ag ion release mechanism in vivo; the biocompatibility, cytotoxicity and antibacterial properties of nano-structured surface of Ti-Ag nanotube/HA also studied in vivo and in vitro. The biocompatibility of Ti-Ag nanotubes/HA in rabbit model by studying the gene expression, bone formation and shear strength around the implants. The Ti-Ag nanotube/HA, Ti-nanotube and Cp-Ti were implanted into femur of the rabbits. Mechanical fixation of the peri-implant-bone area and bone contact were evaluated by pull-out tests and histology, and the gene expression of alkaline phosphatase(ALP), OPN, OCN and collagen-I (Col-I) was examined by using real-time PCR after implantation. The study will develop new nanostructured Ti-Ag nanotube/HA and explore the application for biomaterial for preventing postoperative orthopedic implant-related infection

目前临床上使用的金属内植物(钛金属及其合金)缺乏长期抗菌性能及优越的体内生物相容性（骨整合），本研究组以阳极氧化技术制备钛银合金表面纳米管。通过在模拟体液中在纳米管表面沉积钙磷涂层（即羟基磷灰石）。联合应用钛银纳米管/HA复合涂层优势 :1.低剂量银离子能达到长期抑制假体周围细菌粘附增殖(缓释银离子)；2.表面纳米管能够促进骨组织生长；3.纳米管具有抑制细菌粘附的作用。本研究将利用扫描电镜对其进行表征分析检测；在动物模型中进行银离子释放研究；评价钛银合金纳米管组织相容性、细胞毒性及抗菌性能。检测大兔模型检测假体周围骨长入，成骨相关基因及内植物与周围骨的结合力等。骨长入情况及内植物与周围股情况等通过BIC试验及拉力试验（pull out test) 检测，同时内植物周围组织的成骨相关基因（OPN,OCN, COL-1, ALP)等通过实时定量PCR技术检测。我们将探索其抗菌性能及应用基础研究

目前临床上使用的金属内植物(钛金属及其合金)缺乏长期抗菌性能及优越的体内生物相容性（骨整合），研究组以阳极氧化技术制备钛银合金表面纳米管。在我们的研究过程中发现钛银合金纳米管有着良好的抗菌性能及生物相容性。通过在模拟体液中在纳米管表面沉积钙磷涂层，在金属浸提液中银离子能够缓慢释放。低剂量银离子能达到长期抑制细菌粘附增殖(缓释银离子)；表面纳米管能够促进骨组织生长。钛银合金纳米管组织相容性、细胞毒性及抗菌性能均得到证实。动物模型检测发现钛银合金纳米管周围骨长入良好，成骨相关基因增加及内植物与周围骨的结合力增加等。目前项目组已经熟练掌握通过调整实验参数将钛金属表面从微米化到纳米化，从孔状结构到管状结构的制备。复合材料表面载药及沉积生物活性物质如羟基磷灰石等相关研究。