Dual functionalization of titanium with vascular endothelial growth factor and β-defensin analog for potential application in keratoprosthesis

Abstract

Functionalization of material surfaces can improve their biointegration and bactericidal effect. To expand the biomedical applications of titanium in artificial cornea implantation surgery, titanium alloy substrates were coated with polydopamine and dual bound with recombinant vascular endothelial growth factor (VEGF) and anti-microbial peptide (AMP), SESB2V. Successful chemical binding was assessed with attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Coating thickness was assessed by atomic force microscopy. Cellular studies revealed that the functionalized substrates displayed the abilities to enhance primary human corneal fibroblast adhesion, proliferation, and viability. Angiogenesis assay with human mesenchymal stem cells was used to verify the biological functions of immobilized VEGF while bactericidal assay was evaluated for the anti-microbial activities of immobilized SESB2V peptide. We found that the titanium surface that was sequentially functionalized with VEGF and SESB2V had enhanced fibroblast proliferation and anti-microbial properties. The incorporation of such peptides into an artificial cornea implant is important for implant-tissue integration and wound healing. This may improve implant integration and reduce the risk of device infection following artificial cornea implantation.