Effects of Nano-Hydroxyapatite-Coated Platelet-Rich Fibrin on In Vitro Wound Healing of Gingiva-Derived Mesenchymal Stem Cells

Abstract Objectives: Platelet-rich fibrin (PRF) contains bioactive mediators that may support cellular events involved in wound healing. This study compared the effects of conditioned media derived from leukocyte- and platelet-rich fibrin (L-PRF), nano-hydroxyapatite-modified PRF (HA-PRF), and titanium-prepared PRF (T-PRF) on gingiva-derived mesenchymal stem cell (GMSC) wound closure using an in vitro scratch assay. Materials and Methods : GMSCs were isolated from gingival tissue obtained from a healthy donor and characterized before experimental use. L-PRF, HA-PRF, and T-PRF membranes were prepared under identical centrifugation conditions, and conditioned media were collected after 1 or 3 days of incubation. GMSCs were seeded in 24-well plates, serum-starved, and subjected to a linear scratch. Following exposure to the respective conditioned media, residual wound areas were evaluated at 0, 6, 12, 24, 30, and 36 h. Comparisons among the control, L-PRF, HA-PRF, and T-PRF groups were performed at each observation time using one-way ANOVA, followed by Tukey’s post hoc test where appropriate. Results : For 1-day conditioned media, no significant differences among groups were observed at 6, 12, or 24 h (all p > 0.05), whereas a significant between-group difference was detected at 30 h (p = 0.005), when complete wound closure had occurred in the L-PRF and HA-PRF groups. For 3-day conditioned media, no significant between-group difference was observed at 6 h (p = 0.209), whereas a significant difference emerged at 12 h (p < 0.001). At 12 h, HA-PRF showed the smallest residual wound area (33.93 ± 7.96%), compared with L-PRF (57.71 ± 9.46%), T-PRF (69.44 ± 9.25%), and control (80.91 ± 5.33%). Complete wound closure was achieved in the HA-PRF group by 24 h and in the L-PRF group by 30 h, while all groups reached complete closure by 36 h. Direct comparison of the 1- and 3-day conditioned media showed significantly smaller residual wound areas with 3-day HA-PRF-conditioned medium at 6 h (p = 0.024) and 12 h (p = 0.011). Conclusions : PRF-conditioned media supported GMSC wound closure, with HA-PRF showing the most favorable early response, particularly with conditioned medium collected after 3 days. These findings suggest that nano-hydroxyapatite modification may enhance the early biological activity of PRF; however, further mechanistic and in vivo studies are required. Clinical Relevance : Nano-hydroxyapatite modification of PRF may enhance early GMSC-mediated wound closure and may represent a promising approach for improving the regenerative potential of PRF in oral and periodontal wound healing.