Heparin-bound transforming growth factor-β3 enhances neocartilage formation by rabbit mesenchymal stem cells

Background. Heparin binds growth factors to form a stable complex that maintains the biological activity and can retard the release pattern. To differentiate the embedded the stem cells, heparin-bind transforming growth factor (TGF)-beta 3 was mixed with rabbit mesenchymal stem cells encapsulated with thermo-reversible hydrogel. It is suggested that the heparin-bound TGF-beta 3 would help to increase the chondrogenic differentiation of rabbit mesenchymal stem cells in thermo-reversible hydrogel. Methods. To determine the optimal condition for neocartilage formation, we characterized hydrogel constructs with growth factor release profiles, confocal laser microscopy, reverse transcription-polymerase chain reaction analysis, and histology. Results. Reverse transcription-polymerase chain reaction analysis of the resultant cartilage tissue revealed that a thermo-reversible hydrogels with a heparin-bound TGF-beta 3 was optimal for cartilage tissue formation as measured by production of collagen Type II, aggrecan, and SOX9, and cartilage oligomeric matrix protein gene expression. Additionally, the proliferation rate and cartilage specific ECM production were both significantly greater in the presence of heparin-bound TGF-beta 3 than in the control. The amount of cartilage-associated ECM proteins was examined by immunohistochemical staining (collagen type II), Safranin-O staining, and Alcian blue staining. Conclusions. These data indicate the potential use of heparin-binding TGF beta-3 for reconstruction of neocartilage formation.