Chondrogenic differentiation of bone marrow stromal cells in transforming growth factor-β₁ loaded alginate bead

We developed alginate beads loaded with transforming growth factor-β₁ (TGF-β₁) to examine the possible application of the scaffold and cytokine carrier in tissue engineering. In this study, bone marrow stromal cells (BMSCs) and TGF-β₁ were uniformly encapsulated in the alginate beads and then cultured in vitro. The cell morphology and shape of the alginate beads were observed using inverted microscope, scanning electron microscope (SEM), histological staining and RT-PCR to confirm chondrogenic differentiation. The amount of the TGF- β₁ released from the TGF-β₁ loaded alginate beads was analyzed for 28 days in vitro in a phosphate buffered saline (pH 7.4) at 37°C. We observed the release profile of TGF-β₁ from TGF-β₁ loaded alginate beads with a sustained release pattern for 35 days. Microscopic observation showed the open cell pore structure and abundant cells with a round morphology in the alginate beads. In addition, histology and RT-PCR results revealed the evidence of chondrogenic differentiation in the beads. In conclusion, these results confirmed that TGF-β₁ loaded alginate beads provide excellent conditions for chondrogenic differentiation.