Nanohydroxyapatite/Peptide Composite Coatings on Pure Titanium Surfaces with Nanonetwork Structures Using Oyster Shells

Abstract

Titanium and its alloys are extensively applied in artificial tooth roots because of their excellent corrosion resistance, high specific strength, and low elastic modulus. However, because of their biological inertness, their surface needs to be modified to improve the osteointegration of titanium implants. The preparation of biologically active calcium–phosphorus coatings on the surface of an implant is one effective method for enhancing the likelihood of bone integration. In this study, osteoinductive peptides were extracted from oyster shells by using acetic acid. Two peptide-containing hydroxyapatite (HA) composite coatings were then prepared: one coating was prepared by hydrothermally synthesizing an HA coating in the presence of peptides (HA/P/M), and the other coating was prepared by hydrothermally synthesizing HA and then immersing the hydrothermally synthesized HA in a peptide solution (HA/P/S). Characterization results indicated that the composite HA coatings containing oyster shell-based peptides were successfully prepared on the alkali-treated pure titanium surfaces. The HA/P/M and HA/P/S composite coatings were found to exhibit excellent hydrophilicity. Protein adsorption tests confirmed that the HA/P/M and HA/P/S coatings had an approximately 2.3 times higher concentration of adsorbed proteins than the pure HA coating.