Inducing Osteogenesis in Human Pulp Stem Cells Cultured on Nano-Hydroxyapatite and Naringin-Coated 3D-Printed Poly Lactic Acid Scaffolds

Background: Regeneration dentistry demonstrates significant challenges due to the complexity of different dental structures. This study aimed to investigate osteogenic differentiation of human pulp stem cells (hDPSCs) cultured on a 3D-printed poly lactic acid (PLA) scaffold coated with nano-hydroxyapatite (nHA) and naringin (NAR) as a model for a dental regenerative. Methods: PLA scaffolds were 3D printed into circular discs (10 x 1 mm) and coated with nHA, NAR, or both. Scaffolds were cultured with hDPTCs to identify cellular morphological changes and adhesion over incubation periods of 3, 7, and 21 days using SEM. Then, the osteogenic potential of PLA, PLA/nHA/NAR, or PLA scaffolds coated with MTA elutes (PLA/MTA scaffolds) were evaluated by measuring mineralized tissue deposition using calcium concentration assays and alizarin red staining (ARS). Also, immunofluorescence labelling of alkaline phosphatase (ALP) and dentine sialophosphoprotein (DSPP) within cultured cells were evaluated. Results: The highest cellular attachment was identified on the PLA/nHA/NAR scaffold, with morphological changes reflecting cellular differentiation. The highest calcium deposition and ARS were recognized in the PLA/nHA/NAR culture, with statistically significant difference (p < 0.05) compared to PLA/MTA. Also, ALP and DSPP markers showed statistically significantly higher (p < 0.05) immunoreactivity in cells cultured within PLA/nHA/NAR compared to PLA/MTA. Conclusions: The results confirm the osteogenic potential of PLA scaffolds coated with nHA/NAR for future animal and human investigations.