心肌梗死局部注射壳聚糖水凝胶材料的存留和降解

背景：研究发现壳聚糖水凝胶可促进受损组织新生血管生成,修复损伤细胞和组织。目的：观察心肌梗死部位局部注射壳聚糖水凝胶材料的存留和降解及其对心脏功能的保护作用。方法：结扎Wistar大鼠冠状动脉左前降支致心肌梗死30 min 后,随机抽签法分为壳聚糖水凝胶注射组、心肌梗死模型组、PBS注射组。术后1,2,4 周使大鼠心脏停留在舒张期行心肌组织学检查,术后4周进行心电图、心脏超声检测,并进行大鼠颈动脉插管,检测心脏功能和心室内压。结果与结论：壳聚糖水凝胶注射1,2 周后在心肌组织中有明显存留,4 周后已降解吸收,无明显残留。注射4周后心脏超声、心室血流动力学及心室内压检测结果表明,壳聚糖水凝胶注射组心脏功能明显好于心肌梗死模型组、PBS 注射组,而心肌梗死模型组和PBS 注射组之间没有明显的区别。说明以壳聚糖为支架材料,应用配制的可注射性液态支架进行心肌梗死局部注射治疗,注射4周后无明显残留,保护和改善了心脏功能,适宜作为可注射性组织工程化心肌的支架材料。

Residual and degradation of chitosan hydrogel injected into infarcted myocardium

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.