The Influence of Adipose-Derived Stem Cells Induced into Endothelial Cells on Ectopic Vasculogenesis and Osteogenesis

Established vascular network has a crucial importance in bone regeneration. Adipose-derived stem cells (ADSCs) can be differentiated in vitro towards endothelial cells (ECs) that give a possibility for their application in bone tissue engineering (BTE). The aim of our study was to examine the influence of ADSCs in vitro induced into ECs on vascularization and osteogenic process in subcutaneous implants. Induced ADSCs were implanted subcutaneously into BALB/c mice, in combination with the bone mineral matrix carrier (BC) and platelet-rich plasma (PRP), parallel with the implants without the cells. The combination of BC, PRP and ADSCs induced into ECs increased vascularization in subcutaneous implants that was shown through endothelial-related gene expression, high percentage of vascularization and VEGFR-2 immunoexpression. Osteocalcin immunoexpression, relative expression of osteopontin gene, and histological analysis showed that osteogenic process was more pronounced when the carrier was loaded with ADSCs induced into ECs which was associated with strong vascularization in cellularized implants. In implants without the cells vasculogenesis was initially stimulated, but vascular network was unsustainable at later observation points. Therefore, the approach that includes ADSCs in vitro induced into ECs combined with BC and PRP can be a good strategy for improving vascularization in bone regeneration and BTE.