Fabrication of a porous hydroxyapatite scaffold with enhanced human osteoblast-like cell response via digital light processing system and biomimetic mineralization

In this study, we developed a photocurable hydroxyapatite (HA) slurry with 43 vol% HA content for a digital light processing (DLP) printing system. We assumed that the biomimetic mineralization coated on the surface of the DLP-printed porous HA scaffold could improve the in vitro cell response of the DLP-printed scaffold, such as in regards to cell adhesion or proliferation. Therefore, to verify the influence of biomimetic mineralization coated on the DLP-printed scaffold, the characteristics of the biomimetic mineralized HA scaffold (S-HA scaffold) were compared with those of HA bulk and HA scaffolds. It was found that the influences of the biomimetic mineralization on the structural characteristics of the HA scaffold were negligible, such as those on the apparent pore size, porosity, and compressive strength. However, the biomimetic mineralization coated on the surface of the HA scaffold improved the cell adhesion, proliferation, ALP activity, and gene expressions (runx2 and osteopontin) relative to the HA bulk and HA scaffolds, owing to the interconnected pores and increased nano-topology from the biomimetic mineralization. Therefore, we revealed that the in vitro cell response of a DLP-printed HA scaffold could be enhanced by biomimetic mineralization.