紫外线对钛表面蛋白吸附及竞争吸附的影响

Effect of ultraviolet-photofunctionalization of titanium on protein adsorption and competition

目的 研究紫外线照射前后钛表面牛血清白蛋白（bovine serum albumin,BSA）和血纤蛋白原（fibrinogen,Fg）的吸附及竞争吸附行为,探讨紫外线对钛表面蛋白吸附的影响,为光功能化应用于钛种植体表面改性提供依据.方法 抛光钛试件及石英晶体微天平（quartz crystal microbalance with dissipation,QCM-D）钛芯片常温常压避光保存4周后,按是否接受紫外线照射分为光照组和对照组.检测两组钛试件1、12、24 h Fg吸附量（每组每时间点3个钛试件）.原子力显微镜观察两组同时滴加Fg和BSA 1 h后吸附形貌（每组2个钛芯片）.QCM-D监测两组Fg、BSA 24 h吸附量,并按不同顺序通入BSA和Fg进行竞争吸附实验.结果 光照组Fg 1和12h吸附量[分别为（0.250±0.005）和（0.172±0.006） mg]均显著高于相应对照组[（0.207±0.004）和（0.144±0.004） mg]（P＜0.05）,而24 h吸附量[（0.080±0.003） mg]显著低于相应对照组[（0.127±0.004） mg]（P＜0.05）.原子力显微镜显示光照组蛋白量较对照组密集.QCM-D示光照组Fg和BSA 1 h吸附量均高于对照组.竞争吸附显示在BSA吸附稳定后通入Fg,两组钛芯片表面蛋白层质量均增加;但在Fg吸附稳定后通入BSA,对照组蛋白层质量无明显改变,而光照组蛋白层质量轻度下降.结论 紫外线光功能化能促进钛表面蛋白吸附,并对Fg和BSA的竞争趋势无影响.

Objective To study the adsorption behavior of bovine serum albumin（BSA） and fibrinogen（Fg） and the competition of them on titanium before and after ultraviolet（UV）-photofunctionalization,and to provide the evidence of photofunctionalization on the surface modification of titanium implants.Methods Titanium disks and sensors of quartz crystal microbalance-D（QCM-D） were stored and sealed in the dark for 4 weeks before being divided into two groups,namely the UV-treated group and control group.Samples in the UV-treated group were treated with UV rays for 48 hours.Then the Fg adsorbing property of disks in both groups was tested at 1,12 and 24 h.Protein films of Fg and BSA formed on QCM sensors after 1 h incubation were imaged via atomic force microscopy（AFM）.Then with QCM-D,for both surfaces the adsorption of Fg and BSA as well as the competition between them was tested by introducing proteins with different sequences.Results After being incubated for 1 and 12 h,UV-treated group attracted more Fg[（0.250±0.005） and （0.172±0.006） mg] than control group did[（0.207±0.004） and （0.144±0.004） mg]（P〈0.05）.However,after 24 h incubation,Fg residual on the UV-treated group[（0.080± 0.003） mg] was smaller than that in the control group[（0.127± 0.004） mg] （P〈0.05）.AFM showed protein clustered more densely on UV-treated surfaces than control surfaces and QCM displayed the same result.In addition,when Fg was introduced into QCM-D after BSA,the mass of protein film increased on both surfaces.However,when BSA was introduced after Fg,the mass of protein film on the control group had no change,but slightly decrease on the UV-treated group.Conclusions UV-photofunctionalization promotes protein adsorption but has no influence on the competition between Fg and BSA.