Polydopamine-assisted functionalization of heparin and vancomycin onto microarc-oxidized 3D printed porous Ti6Al4V for improved hemocompatibility,osteogenic and anti-infection potencies

聚多巴胺辅助微弧氧化后载肝素和万古霉素以提高3D打印多孔钛合金内植物的血液相容性和抗菌成骨功能（英文）

Enhanced antiinfection activities, improved hemocompatibility and osteo-compatibility, and reinforced osseointegration are among the most important considerations in designing multifunctional orthopedic biomaterials.Hereby, anti-infective and osteogenic multifunctional 3 D printed porous Ti6 Al4 V implant with excellent hemocompatibility was successfully designed and fabricated. In brief, osteogenic micro-arc oxidation（MAO） coatings with micro/nanoscale porous topography were generated in situ on3 D printed Ti6 Al4 V scaffolds, on which heparin and vancomycin were easily immobilized. The surface microstructure,morphology, and chemical compositions were characterized employing scanning electron microscopy（SEM）, X-ray photoelectron spectroscopy（XPS） and Fourier transform infrared spectroscopy（FTIR）. High loading capacity and sustained vancomycin release profiles were revealed using high performance liquid chromatography（HPLC）. Favorable antibacterial and antibiofilm performances against pathogenic Staphylococcus aureus（S. aureus） were validated in vitro through microbial viability assays, Live/Dead bacterial staining, and crystal violet staining. Human mesenchymal stem cells（h MSCs） were seeded on the scaffolds and their proliferation and viability were assessed using Cell Counting Kit and Live/Dead cell viability kit. Further, osteoblastic differentiation abilities were evaluated using alkaline phosphatase（ALP） activity as a hall marker. Additionally, the improved hemocompatibility of the heparinized scaffolds was confirmed by activated partial thromboplastin time（APTT）, prothrombin time（PT） and thrombin time（TT）. Overall, our results show that the surface-modified 3 D printed porous Ti6 Al4 V possesses balanced antibacterial and osteogenic functions while exhibiting extra anticlotting effects, boding well for future application in customized functional reconstruction of intricate bone defects.

在研发多功能骨科生物材料时,抗菌能力、血液相容性、骨细胞相容性和骨整合性能是最重要的考虑因素.本文中,我们成功研发了具有良好血液相容性的抗菌、促成骨复合功能的3D打印多孔钛合金内植物.简言之,3D打印多孔钛合金支架经表面处理后具有多孔形貌的微弧氧化促成骨涂层,进而联结固定肝素钠和万古霉素.本文采用扫描电镜、X射线光电子能谱分析和傅里叶变换红外光谱学对其表面微观结构、形态和化学组成进行了表征,并用高效液相色谱法检测了其载药能力和万古霉素释放曲线.通过微生物检测、细菌死活染色和结晶紫染色,确定了其良好的抗金葡菌及菌膜性能.将人骨髓间充质干细胞在支架上培养后,用细胞计数试剂盒和细胞活性检测试剂盒检测了其增殖活性.此外,用碱性磷酸酶成活性作为标记检测了成骨细胞分化能力,通过检测活化部分凝血活酶时间、血浆凝血酶原时间和凝血酶时间,确定肝素化的支架血液相容性得到了提高.该研究结果表明,经过表面改性的3D打印多孔钛合金内植物拥有稳定的抗菌和促成骨功能,同时显现出抗凝特性.预示着其在未来能用于复杂骨缺损的定制化功能重建.