Biofabrication and Characterization of Fluorapatite-Coated Poly(lactic-co-glycolic acid) Microscaffolds: Physicochemical Properties and Human Dental Pulp Stem Cell Responses

Abstract

Biodegradable polymeric scaffolds incorporating bioactive mineral phases are a promising approach for dentin-pulp tissue engineering. Although poly(lactic-co-glycolic acid) (PLGA) microparticles have been widely used as scaffolds due to their biocompatibility and tunable degradation profile, their inherent bioactivity is limited. Furthermore, fluorapatite (FAP), a fluoride-substituted apatite ceramic, exhibits enhanced chemical stability and mineral-related properties that may be useful for regenerative biomaterial design. In this study, we investigated the effect of nano-FAP functionalization on the physicochemical properties of porous PLGA microscaffolds and their interaction with human dental pulp stem cells (hDPSCs). Porous PLGA microscaffolds were fabricated using a double-emulsion solvent evaporation method and subsequently functionalized with FAP suspensions ranging from 0.1 to 5 mg/mL (0.01–0.5% w/v). The scaffolds were evaluated using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), electrical conductivity measurements, cell viability assays, and immunofluorescence. Lower and intermediate FAP concentrations-maintained surface pore accessibility and supported hDPSC viability, whereas the highest concentration (5 mg/mL; 0.5% w/v) reduced visible surface pore size and showed less favorable cellular responses. The 2.5 mg/mL (0.25% w/v) FAP condition provided the most favorable overall balance among the evaluated physicochemical and biological parameters. These preliminary in vitro findings support further investigation of FAP-functionalized PLGA microscaffolds in advanced three-dimensional and in vivo models.