3D打印梯度多孔钛合金支架表面纳米结构化改性

Surface Nano-Structural Modification of Gradient Porous Titanium Alloy Scaffolds by 3D Printing

通过3D打印技术制备具有梯度结构的微米级多孔钛合金支架,解决了不同患者对骨缺损修复支架的个性化需求。然而,由于钛合金本身的生物惰性,多孔钛合金支架植入人体后骨整合能力较差。为提高支架的生物活性,采用电化学阳极氧化对多孔支架表面进行纳米结构化改性。本文探究了氧化电压、氧化时间和电解液对梯度多孔钛合金表面制备TNTs(二氧化钛纳米管)的影响规律。结果表明,采用两次阳极氧化的方法,电解液为0.3wt%氟化铵+2vol%去离子水+1.5mol/L乳酸的乙二醇溶液,氧化电压为100 V,氧化时间为1 h时,可在支架表面制备出形貌高度有序的TNTs涂层。对氧化处理后的多孔钛合金支架进行500℃退火处理,表面TNTs涂层的晶型结构由无定型结构转变为更有利于蛋白吸附和细胞增殖的锐钛矿和金红石的混合晶型结构。通过电化学腐蚀试验发现经过阳极氧化处理的多孔钛合金支架具有更好的耐腐蚀性。

Micrometer-grade porous titanium alloy scaffolds with gradient structure were prepared by 3D printing technology to meet the personalized needs of different patients for bone defect repair scaffolds.However,due to the biological inertia of titanium alloy itself,the bone integration ability of porous titanium alloy scaffolds is poor after implantation.In order to improve the biological activity of scaffolds,nanostructured modification of the porous scaffold surface was performed by electrochemical anodic oxidation.The influence of oxidation voltage,oxidation time and electrolyte on the preparation of TNTs on the surface of gradient porous titanium alloy was explored.The results show that when the two-step anodic oxidation method is used,and the composition of the electrolyte is glycol solution containing 0.3wt%ammonium fluoride+2vol%deionized water+1.5 mol/L lactic acid,and the oxidation voltage is 100 V,the oxidation time is 1h,TNTs coating with high ordered morphology can be prepared on the surface of the scaffold.After oxidation treatment,the porous titanium alloy scaffold is annealed at 500℃,the crystal structure of the surface TNTs changes from amorphous structure to the mixed crystal structure of anatase and rutile,which is more favorable for protein adsorption and cell proliferation.Through electrochemical corrosion test,it is found that the porous titanium alloy scaffold treated by anodic oxidation has better corrosion resistance.