Abstract:

BACKGROUND: Chitosan hydrogel can promote angiogenesis in damaged tissue, repair damaged cells and tissues.
OBJECTIVE: To investigate the effect of chitosan hydrogel injected into the infarcted area of rat heart to protect and improve the cardiac function, and its residual and degradation. 
METHODS: The left coronary artery of Wistars rat was occluded for infarction, and 30 minutes later they were randomly divided into three groups: myocardial infarction (MI) group, MI + PBS group and MI + chitosan hydrogel group. At 1, 2, 4 weeks after injection, animal models were sacrificed, to keep heart stay at diastolic phase to be excised and sectioned for histological detection; at 4 weeks after injection, animals were anesthetized for electrocardiogram and cardiac ultrasonography test, and arterial cannula was performed to test intraventricular pressure. 
RESULTS AND CONCLUSION: Obvious residuals in cardiac muscle tissue may be observed at 1 and 2 weeks after chitosan hydrogel injection, while the residuals disappeared 4 weeks after chitosan hydrogel injection; However, the cardiac ultrasonography, ventricle hemodynamics and intraventricular pressure results showed that the cardiac function of animals in MI + chitosan hydrogel group was better than that in MI group and MI + PBS group at 4 weeks, but there was no obvious difference between MI group and MI + PBS group. Injection of chitosan hydrogel into the infarcted area of the left ventricle may protect and improve cardiac function without any residuals after 4 weeks, so the chitosan hydrogel may be used as a good scaffold material in injectable myocardium tissue engineering.