Cardiac Tissue Engineering Based On The CNT-Decellularized Matrix Hydrogel

Objective:In this study we constructed the heart decellularized matrix hydrogel with good gelling performance and stable bioactive components. And after carbon nanotubes (CNT) modified, high dispersion of the CNT composite hydrogel were obtaied. We observe the impact of the material on myocardial cell proliferation and maturation, and explore its impact mechanism. In addition, we further studied the material on brown fat derived stem cells (BADSCs) proliferation, differentiation into cardiomyocytes and maturation of function. By MI transplantation experiments, we evaluate its effect on cardiac function improvement, repair effect and its impact on BADSCs differentiation into cardiomyocytes for further application in cardiac tissue engineering research.Methods:1) Based on the use of quick freezing-SDS-Triton combined perfusion system, we obtained the whole heart decellularized matrix; then, the matrix was lyophilized, crushed and enzymatic hydrolysis to hydrogel. The microstructure of the composite material was observed by SEM and TEM, an atomic force microscope to measure the elastic modulus, and the conductivity was evaluated by electrochemical workstation.2) We used cardiomyocytes as seed cells, studied the effects of carbon nanotubes on myocardial cell proliferation and mature, then explore its impact mechanism. 3) We evaluated the effects of carbon nanotubes on BADSCs proliferation, differentiation into cardiomyocytes and functional maturation, then constructed a three-dimensional cardiac tissue to observe the growth and differentiation of BADSCs in a three-dimensional material environment.4) We prepared myocardial infarction in rats and did a materials transplant surgery, observed the cells stranded after one week, evaluated myocardial infarction size, differentiation of transplanted cells and heart function by Masson staining, fluorescent staining and ultrasound evaluation after 4 weeks.Results:1) Preparation of a rat heart dcellularized matrix hydrogel with good gelling ability and stability of bioactive components, and uniformly dispersed CNT in it.2) Conductivity and mechanical properties of CNT modified dcellularized matrix hydrogel has significantly enhanced.3) Metabolic activity of cardiomyocyte and BADSCs was significantly enhanced in 1.0mg/ml of CNT concentration.4) CNT can promote the expression of cardiomyocyte cTnT and Cx43, and can enhance myocardial cell electrophysiological activity.5) CNT can promote the proliferation and metabolism of BADSCs and significantly increase the expression of a-actinin and cTnT, electrical activity was also significantly higher than the control group.6) Constructed three-dimensional myocardial tissue which had a certein beat function based on CNT-decelluarized matrix. 7) CNT-decelluarized matrix hydrogel carry BADSCs transplantation can reduce infarct size, and improved cardiac pumping function after 4 weeks.Conclusion:1) CNT can significantly increase the mechanical properties and electrical conductivity of composite material.2) CNT can promote the proliferation and maturation of cardiomyocytes, possibly by promoting the expression of Cx43 and strengthen the transfer of electrical signals between cells, thus contributing to the cardiac electrophysiology maturation.3) CNT can promote the proliferation and metabolic activity of BADSCs, and significantly promot its differentiation and maturation.4) CNT-dcellularized matrix hydrogel carry BADSCs transplatatinon can improve local micro-environment, and significantly improve heart function, and the treatment has broad application prospects.