RESUMO
PURPOSE: We investigated the effects of recombinant 9-10th type III repeat of fibronectin (rhFNIII9-10) on the adhesion, proliferation, and the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells(hMSCs). MATERIALS AND METHODS: Adhesion and blocking assay for hMSCs were performed on the plates which had been coated with 100 microgram/ml rhFNIII9-10 or fibronectin. hMSCs seeded on the precoated plates were cultured in the osteogenic media for 3 weeks. MTS(Dimethylthiazole carboxymethoxyphenyl sulfophenyl tetrazolium compound) assay for the cell number, [Methyl-3H] thymidine incorporation study, alkaline phosphatase activity assay, calcium content assay and RT-PCR for alkaline phosphatase, osteopontin, cbfa-1, and type I collagen were performed during the osteogenic differentiation. RESULTS: hMSCs showed significantly increased adhesion to rhFNIII9-10-coated plates and fibronectin-coated plates. A monoclonal antibody to the integrin alpha 5 beta 1 inhibited adhesion to rhFNIII9-10-coated plates and fibronectin-coated plates in dose-dependent manner. hMSCs seeded on the rhFNIII9-10-coated plates showed increased proliferation during the osteogenic differentiation. However, there was no significant difference in the alkaline phosphatase activity, calcium content and expression levels of mRNAs for alkaline phosphatase, osteopontin, cbfa-1, and type I collagen of hMSCs seeded on the rhFNIII9-10-coated plates. CONCLUSION: rhFNIII9-10 stimulates hMSCs adhesion and increases hMSCs proliferation during the osteogenic differentiation. Although osteogenic differentiation is not promoted, adsorption of rhFNIII9-10 onto appropriate biomaterials can enhance integrin-mediated hMSCs adhesion and proliferation. This biomolecular engineering strategy represents a robust approach to increase biofunctional activity and integrin specificity of hMSCs.