Abstract
BACKGROUND: Human periosteal cells (hPCs) possess high osteogenic potential and are considered promising candidates for regenerative therapy. Recombinant human collagen peptide (RCP), a xeno-free biomaterial enriched with arginine-glycine-aspartic acid (RGD) sequences, provides a stable and biocompatible scaffold that may enhance cellular functions. OBJECTIVES: This study aimed to evaluate the biocompatibility of RCP with hPCs and its effects on osteogenic functions in vitro and in vivo. MATERIALS AND METHODS: Cell viability was assessed by MTT assay at various RCP concentrations. Cell adhesion and migration were examined using fluorescence-based adhesion and Oris™ migration assays. Gene expression profiles were analyzed by RNA-sequencing and quantitative PCR. Alkaline phosphatase assay (ALP) and Alizarin Red staining (ARS) were performed to evaluate osteogenic differentiation. For in vivo analysis, a rat calvarial critical-size defect model was used to evaluate bone regeneration following transplantation of hPCs with or without RCP. RESULTS: RCP exhibited no cytotoxic effects and enhanced the adhesion and migration of hPCs. RNA-seq and qPCR analyses revealed upregulation of extracellular matrix- and osteogenesis-related genes, including COL1A1, SERPINH1, ALP, RUNX2, and OCN. Moreover, RCP enhanced osteogenic differentiation, as demonstrated by increased ALP activity and greater calcium deposition in ARS. In vivo, micro-CT analysis showed no significant difference in new bone volume among groups, whereas immunohistochemical analysis revealed increased numbers of OCN- and BMP-2-positive cells in RCP-treated defects, indicating enhanced osteogenic activity. CONCLUSION: RCP supports the osteogenic potential of hPCs by promoting adhesion, migration, and osteogenesis-related gene expression, and enhancing osteogenic activity in vitro and in vivo. These findings suggest that RCP is a promising biomaterial for periosteal cell-based regenerative therapies.