Surface Modification of Coronary Stents for Intravascular Gene Delivery

The present study investigated a novel surface modification on metal coronary stent for antibody immobilization. Methods: 316L stainless steel stents were surface modified with protein coatings. An Anti-DNA antibody was covalently bound to the protein surface using a bi-functional cross-linking agent SPDP. The artwork and binding stability of protein coatings were evaluated by in-vitro eluting. The feasibility and stability of anti-DNA antibody covalently bound to the stent were evaluated by means of 125I labeling. Results: We observed that pre-treating the steel surface using diluted HCL and increasing the ratio of cross-linking agent caused significantly increased binding stability of the protein coatings (p﹤0.001). The amount of chemically coupled antibody on the stents was 8 times higher than that of physically absorbed control stents. The stability of chemically coupled antibody on the stent was significantly better than physically absorbed control. Conclusion: It is concluded that we optimized the technique of protein coating on stainless steel and achieved stable anti-DNA antibody immobilization, therefore enabled efficient and highly localized non-viral gene delivery.