Enhancing the bioactivity of yttria-stabilized zirconia immobilized with adhesive peptide using l-dopa as cross-linker

To resolve the disadvantages of the bio-inert nature of zirconia ceramics and their poor bonding to bone tissue, surface modification to enhance tissue integration usually has to be performed. In this study, we developed a simple, efficient, and organic solvent-free biomimetic modified strategy through the use of l-dopa, which is known to have strong adhesive behavior, as a cross-linker for immobilization with adhesive peptide. 3Y-TZP was first immersed into l-dopa solution to form a strongly adhesive coating. RGD peptides were then immobilized onto the l-dopa-grafted surface. Several characterization analyses, including static contact angle measurement, FTIR spectroscopy, and Bradford staining, showed that RGD peptides were successfully immobilized onto the 3Y-TZP surface through the l-dopa linker. In vitro assay revealed that a significant increase in MG-63 osteoblast cell attachment, proliferation, and differentiation was observed from SEM, WST-1, and ALP activity on the l-dopa-grafted 3Y-TZP surface with the immobilized adhesive peptide. Thus, the results of this study suggest that l-dopa can be used as a cross-linker to immobilize adhesive peptides onto a 3Y-TZP surface and further enhance bioactivity.