Electrodeposition of Hydroxyapatite on a Metallic 3D-Woven Bioscaffold

In this study, we demonstrate that a uniform coating of hydroxyapatite (HAp, Ca10(PO4)6(OH)2) can be electrochemically deposited onto metallic 3D-woven bone scaffolds to enhance their bioactivity. The HAp coatings were deposited onto metallic scaffolds using an electrolyte containing Ca(NO3)2·4H2O, NH4H2PO4, and NaNO3. The deposition potential was varied to maximize the uniformity and adhesion of the coating. Using X-ray diffraction (XRD), Raman spectroscopy, and energy-dispersive spectroscopy (EDS), we found crystallized HAp on the 3D-woven lattice under all deposition potentials, while the −1.5 V mercury sulfate reference electrode potential provided the best local uniformity with a satisfactory deposition rate. The coatings generated under this optimized condition were approximately 5 µm thick and uniform throughout the internal and external sections of the woven lattice. We seeded and cultured both coated and uncoated scaffolds with human adipose-derived stromal/stem cells (ASCs) for 12 h and 4 days. We observed that the HAp coating increased the initial cell seeding efficiency by approximately 20%. Furthermore, after 4 days of culture, ASCs cultured on HAp-coated stainless-steel scaffolds increased by 32% compared to only 17% on the uncoated scaffold. Together, these results suggest that the HAp coating improves cellular adhesion.