Surface engineering of zirconia with abaloparatide and nano-hydroxyapatite for synergistic osteogenic activity

We report on the surface engineering of zirconia (ZrO₂) by incorporation of abaloparatide (ABL) on the surface of nano-hydroxyapatite (nHAp)-immobilized zirconia. First, nHAp-immobilized zirconia (nHAp–PDA–ZrO₂) was fabricated by adding nHAp in a polydopamine (PDA)-coating process on zirconia surface. Surface chemistry, morphology, and wettability of nHAp–PDA–ZrO₂ were examined using X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), and water contact angle measurement. As a second step, ABL incorporation was performed by the reaction of ABL with PDA layer coated on nHAp–PDA–ZrO₂. A fluorescence microscope visualized that ABL was efficiently bound on the surface of nHAp–PDA–ZrO₂to form ABL/nHAp–PDA–ZrO₂. The synergistic osteogenic effect of ABL and nHAP on alkaline phosphatase (ALP) activity, calcium-mineral deposition, and alizarin red staining were assessed. The combination of ABL and nHAp for surface-engineering approaches may provide an effective approach to develop highly promising bone-regenerative osteogenic implant surfaces.

The surface of zirconia is engineered by incorporation of bone-forming abaloparatide (ABL) and osteoconductive nano-hydroxyapatite (nHAp). This ABL/nHAp-functionalized zirconia surface exhibits synergistic improved osteogenic activity.