The favorable role of recombinant collagen peptide in periosteal cell-derived osteoregeneration

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. This study aimed to evaluate the biocompatibility of RCP with hPCs and its effects on osteogenic functions in vitro and in vivo . 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. 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. 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.