Injectable tissue-engineered bone composed of human adipose-derived stromal cells and platelet-rich plasma

This study aimed to evaluate the effects of human platelet-rich plasma (hPRP) on the proliferation and osteogenic differentiation of human adipose-derived stromal cells (hADSCs) and to construct a novel injectable tissue-engineered bone (ITB) composed of hPRP and hADSCs. hADSCs were isolated from liposuction tissues of healthy patients. hPRP was obtained by traditional two-step centrifugation. MTT, alkaline phosphatase (ALP) activity and mineralization assays were used to evaluate the effects of different concentrations of hPRP on cell proliferation and osteogenic differentiation in vitro. hADSCs cultured in optimal concentration of activated hPRP were subcutaneously injected into the inguinal groove of nude mice with hPRP and thrombin. X-ray, H&E staining and immunohistochemical analysis were used to examine the bone formation. Studies in vitro revealed that cell proliferation, ALP activity and mineralization were induced by hPRP and 10–12.5% of hPRP seemed to be the optimal concentration. Studies in vivo showed that this ITB formed bone structure in heterotopic site of nude mice. These findings indicate that the ITB composed of hPRP and hADSCs may represent a prologue for the development of a novel biological solution to bone defect. However, further investigations should be done to fully reveal the characteristics of this ITB.