ZrO₂ surface chemically coated with hyaluronic acid hydrogel loading GDF-5 for osteogenesis in dentistry

The objective of this study was to modify zirconium dioxide (ZrO ₂) with photo-cured hyaluronic acid hydrogel (pcHAgel), and to subsequently evaluate the bone regeneration potential of the modified ZrO ₂. In the present study, HA grafted onto a ZrO₂ substrate was investigated for its biocompatibility and other properties. We describe the positive influences of ZrO₂ surface-modified with pcHAgel (Zr-3) containing two different loads of growth and differentiation factor-5 (GDF-5) to aid new bone formation as compared to the same amount of BMP-2 (Zr-4-7). We characterized the Zr-3 for their surface morphology and chemical properties. Atomic force microscopy (AFM), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) showed that the pcHAgel was successfully grafted onto the ZrO₂ surface. The sustained release of GDF-5 and BMP-2 were observed to occur in the Zr-4-7. In vitro cell tests showed a higher level of MG63 cell proliferation and differentiation on Zr-4-7 than on Zr-3. The Zr-3 is a good biomaterial to deliver osteogenic differentiation factors such as BMP-2 and GDF-5, and GDF-5 can be useful as an effective alternative to aid new bone formation as compared to BMP-2.