Oriented immobilization of anti-CD34 antibody on titanium surface for self-endothelialization induction

Inducing spontaneous endothelialization of synthetic cardiovascular implant in vivo is thought to be a promising approach to solve the surface-induced thrombosis and restenosis problem. In the present study, anti-CD34 antibody, a kind of special marker of EPC, was oriented immobilized on titanium surface by means of a layer-by-layer self-assembly coating technique. The multilayer coating was prepared by first depositing one layer of avidin on the NaOH-treated titanium substrate, then depositing a layer of biotinylated protein A binding to the avidin, and finally anti-CD34 antibody was oriented immobilized by protein A binding to the Fc fragment (COOH-terminal of a antibody molecule, which has no antigen binding sites) of the anti-CD34 antibody with its antigen binding fragment (Fab) away from the titanium surface. The coated titanium was exposed to EPC derived from mouse bone marrow in vitro, and implanted into dog femoral arteries. The results suggested that the anti-CD34 antibody immobilized surfaces could increase EPC attachment and capture, and induce rapid complete endothelialization of the lumenal surface of the implant in vivo. It suggests that the approach described here may be used for fabrication of titanium-based vascular implant surfaces for inducing endothelialization in vivo.