Morphologic, histochemical, and functional analysis of platelet-rich plasma activity on skeletal cultured cells

BACKGROUND: Platelet-rich plasma (PRP) is a medium containing concentrated amounts of growth factors in a form that is easy to handle in regenerative sites. The aim of this study was to assess the effect of PRP on the differentiation of cultured skeletal cells and the capability of PRP to induce the production of some osteogenesis-related molecules and mineralization. STUDY DESIGN AND METHODS: Flow cytometry (cellular antigens), real-time quantitative polymerase chain reaction (RT-qPCR; bone morphogenetic protein [BMP] messengers), alkaline phosphatase (ALP; osteogenic expression), and calcification analyses were performed on 24- and 48-hour human bone cells (HBCs) and 143B and SaOS-2 (osteosarcoma) cell cultures to study the effect of PRP on proliferation and differentiation of skeletal cultured cells. PRP was added using different protocols since no studies are available on bone cultures treated in the long term with PRP. RESULTS: Flow cytometry showed PRP induction toward a nonhemopoietic lineage in HBCs; RT-qPCR showed enhanced mRNA encoding for BMP2 in HBCs, BMP6 and BMP7 in 143B cultures, and BMP2 and BMP7 in SaOS-2 cultures. Better ALP and calcification results were obtained in SaOS-2 cultures when PRP was added more frequently at shorter intervals while poor results were obtained after single PRP addition. CONCLUSIONS: The results highlight induction of bone cell proliferation and differentiation by PRP. Since repeated administration of PRP is needed to achieve the best results, an almost continuous delivery system of PRP, or better a controlled release of growth and differentiation factors, using biomaterials might provide increased performance at bone regeneration sites.