The nanofabrication of CD34 antibody-VEGF-heparin on titanium surface via layer-by-layer assembly for biofunctionalization

To provide a new strategy for biocompatibility of implanted stents, the surface endothelialization of the metal material is paid more attention. In this work, we focus on the nano-building of a biofunctional layer on the titanium surface with CD34 antibody, heparin, and vascular endothelial growth factor (VEGF) for achieving better compatibility surface. Firstly, Titanium was treated by NaOH solution for obtaining negative charge and forming nanostructure which had been proved to be benefit for the biomacromolecules attachment subsequently. Then, the biofunctional layer was nanofabricated by a layer-by-layer self-assembly (LBL) technique with the above biomacromolecules. The chemical composition, surface roughness topography and contact angle of assembled layer were investigated by Fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM), scanning electron microscope (SEM), immunofluorescence and water contact angle measurement, respectively. The biocompatibility of biofunctional layer was evaluated by in vitro endothelial progenitor cells culture, in vitro platelet adhesion experiment and the activated partial thromboplastin time (APTT) measurement, etc. The results disclosed that, comparing to the controlled titanium surface, the endothelialization trend and the anti-thrombosis ability of biofunctional titanium surface were obviously improved. The built layer could capture the EPCs from circulated solutions and induced the EPCs differentiation into endothelial cells (ECs). It was supported that the combination of CD34 antibody and VEGF could significantly promote re-endothelialization of Titanium surface.