Rapid formation of calcium phosphate on chemically treated biodegradable pure zinc for orthopedic applications

This study explores enhancing calcium phosphate (CaP) nucleation and formation on biodegradable pure zinc (Zn) surfaces using a straightforward and repeatable chemical treatment method. Zn samples were acid-etched using a mixture of H₂SO₄, HCl and H 2 O for 0.5 hours and soaked in 5 M NaOH for 24 hours before being immersed in Hank’s balanced salt solution (HBSS) for 7 days to facilitate CaP deposition. The surface properties of both neat (untreated) and treated Zn samples were thoroughly characterized using SEM, XPS, FTIR, and XRD to confirm successful surface modification. The results reveal that the alkali-treated Zn surfaces significantly promote the nucleation and formation of CaP compounds, with these samples demonstrating robust cell attachment and proliferation of directly seeded osteoblasts. These findings suggest that chemical surface modification of Zn implants has significant potential to promote bone formation through improved biocompatibility and osteoblast activity, aiding the development of advanced bone implants with enhanced capabilities. • Pure Zinc metal was chemically modified by acid etching and alkali treatment • The Zn treated surface induced an active site for CaP formation • The treated surface induced rapid formation of CaP minerals • CaP minerals improved cytocompatibility of osteoblasts cells