Application Of Transforming Growth Factor -β1 For Construction Of Tissue Engineering Heart Valve

Part one Effects of Transforming Growth Factor -β1 on Constructing Tissue Engineering Heart Valves in VitroObjective To investigate effects of transforming growth factor-β1 (TGF-β1) on tissue engineering heart valves (TEHV). Methods Porcine aortic valves were decellularized with trypsinase and Triton X-100, and then were seeded by myofibroblasts (MFBs) harvested from rats. They were cultivated in culture medium including TGF-β1 at concentration of 10ng/ml. After two weeks, light and electron microscopic observation were performed. And cell DNA assay, hydroxyproline content together with Max-strain of leaflets were measured. RT-PCR technique was used to analyze expressions of MMP-13 and TIMP-1mRNA. Results Histological investigation showed that cells and extracellular matrix were more bloomy in the valves treated with TGF-β1 than normal culture medium. And DNA assay, hydroxyproline content, Max-strain of leaflets and expression of MMP-13 and TIMP-1mRNA were also increased with the help of TGF-β1. Conclusion TGF-β1 was an important and effective factor for cell proliferation and extracellular matrix growth. It is of great value for constructing tissue engineering heart valves in vitro.Part two Construction of Tissue Engineering Heart Valve by Transforming Growth Factor -β1 Gene Transfected Myofibroblasts. Objective To investigate the effects of TGF-β1 gene transfection on TEHV construction. Methods MFBs were transfected with pcDNA3.0/TGF-β1 plasmid through lipofecta- mine mediated gene transfer, and cultivated by G418 selection for three weeks. They were seeded onto decellularized valve scaffold as group A. Non-transfected MFBs were seeded onto scaffold with TGF-β1 containing and normal culture medium as group B and control. HE staining and scanning electronic microscopy were performed to observe cell proliferation. And cell DNA assay, hydroxyproline content together with Max-strain of leaflets were measured. Results In comparison with group B and control, histological investigation showed that cells and extracellular matrix were more bloomy in group A. And DNA assay, hydroxyproline content and Max-strain of leaflets were also increased in group A. Conclusion pcDNA3/TGF-β1 transfected MFBs can express TGF-β1 stably, and the transfected MFBs can be regarded as one kind of new seed cells for constructing tissue engineering heart valves in vitro.