植酸/氢氧化钙改性对3D打印纯钛多孔结构生物矿化的影响

Phytic Acid/Hydroxide Hydroxide Surface Modification on Biomineralization Properties of 3D Printed Porous Titanium

通过激光3D打印技术制备孔隙率为65%的多孔结构纯钛试样,对试样先进行酸蚀作为表面预处理,再利用植酸与饱和氢氧化钙的混合溶液进行表面活化改性处理。采用扫描电镜(SEM)、X射线光电子能谱仪(XPS)及接触角分析仪对3D打印纯钛改性前后的表面进行表面形貌观察、表面成分分析及表面接触角测试,并将改性处理前后的各组试样浸泡在模拟体液(SBF)中进行生物矿化实验,利用SEM及能谱(EDS)分析其表面生物矿化效果。结果表明:植酸/氢氧化钙表面活化改性处理后的3D打印致密纯钛表面水接触角为21.04°,表现出较好的亲水性,即植酸/氢氧化钙改性处理可大幅提高3D打印多孔结构纯钛的表面润湿性;在植酸/氢氧化钙表面活化改性处理过程中3D打印多孔结构纯钛试样表面通过植酸螯合反应引入了Ca,P元素,可显著加快其表面羟基磷灰石的沉积速度,提高表面生物矿化能力;在浸泡模拟体液7 d后能在改性后3D打印多孔试样的多孔支架上形成羟基磷灰石包裹层。

Porous titanium with a porosity of 65%was prepared by laser 3 D printing.The sample was first subjected to acid etching as a surface pretreatment,and then a surface activation modification treatment was carried out by using a mixed solution of phytic acid and saturated calcium hydroxide.The surface morphology,composition and surface contact angle of 3 D printed pure titanium were analyzed using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and contact angle analyzer before and after surface modification.Mineralization experiments were carried out by immersed in simulated body fluids(SBF),and the surface biomineralization was analyzed by SEM and energy dispersive X-ray spectroscopy(EDS).The results showed that the contact angle of3 D printed dense titanium surface modified with phytic acid/calcium hydroxide was 21.04°,which showed better hydrophilicity,that was,phytic acid/calcium hydroxide modification treatment could greatly improve the wettability of the 3 D printed porous titanium.The phytic acid/calcium hydroxide surface modification treatment introduced Ca and P by chelation reaction on the surface of 3 D printed porous titanium,which could significantly accelerate the deposition rate of hydroxyapatite on the modified surface and improve its biomineralization ability.A hydroxyapatite coating layer could be formed on the porous stent of the modified 3 D printed porous titanium after immersing the SBF for 7 d.