Chuang T-W, Chen M-H, Lin F-H
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, ROC.
J Biomed Mater Res A. 2008 Jun 1;85(3):722-30. doi: 10.1002/jbm.a.31451.
Poor compatibility between blood and metallic coronary artery stents is one reason for arterial restenosis. Immobilization of anticoagulant agents on the stent's surface is feasible for improving compatibility. We examined possible surface-coupling agents for anticoagulant agent immobilization. Hexamethylene diisocyanate (HMDI) and 3-aminopropyl-triethoxysilane (APTS) were examined as surface-coupling agents to activate 316L stainless steel (e.g., stent material). The activated surface was characterized using Fourier transformation infrared spectroscopy (FTIR), atomic force microscope (AFM), surface plasmon resonance (SPR), and trinitrobenzene sulfonic acid (TNBS) assay. In FTIR analysis, HMDI and APTS were both covalently linked to 316L stainless steel. In AFM analysis, it was found that the HMDI-activated surface was smoother than the APTS-activated one. In SPR test, the shift of SPR angle for the APTS-activated surface was much higher than that for the HMDI-activated surface after being challenged with acidic solution. TNBS assay was used to determine the amount of immobilized primary amine groups. The HMDI-activated surface was found to consist of about 1.32 micromol/cm(2) amine group, whereas the APTS-activated surface consisted of only 0.89 micromol/cm(2) amine group. We conclude that the HMDI-activated surface has more desirable surface characteristics than the APTS-activated surface has, such as chemical stability and the amount of active amine groups.
血液与金属冠状动脉支架之间的兼容性差是动脉再狭窄的一个原因。将抗凝剂固定在支架表面对于改善兼容性是可行的。我们研究了用于固定抗凝剂的可能的表面偶联剂。研究了六亚甲基二异氰酸酯（HMDI）和3-氨丙基三乙氧基硅烷（APTS）作为表面偶联剂来活化316L不锈钢（例如支架材料）。使用傅里叶变换红外光谱（FTIR）、原子力显微镜（AFM）、表面等离子体共振（SPR）和三硝基苯磺酸（TNBS）测定法对活化后的表面进行表征。在FTIR分析中，HMDI和APTS均与316L不锈钢共价连接。在AFM分析中，发现HMDI活化的表面比APTS活化的表面更光滑。在SPR测试中，用酸性溶液处理后，APTS活化表面的SPR角位移比HMDI活化表面的高得多。TNBS测定法用于确定固定的伯胺基团的量。发现HMDI活化的表面由约1.32微摩尔/平方厘米的胺基组成，而APTS活化的表面仅由0.89微摩尔/平方厘米的胺基组成。我们得出结论，HMDI活化的表面比APTS活化的表面具有更理想的表面特性，如化学稳定性和活性胺基的量。
