壳聚糖水凝胶局部注射对心梗的治疗作用研究

Experimental studies on local injection with chitosan hydrogel on infarcted area of rat heart

目的观察心梗部位局部注射壳聚糖水凝胶的促血管生成及心肌保护作用。方法将19只Wistar大鼠随机分为壳聚糖水凝胶注射组、单纯心肌梗死模型组、PBS注射组。结扎大鼠冠状动脉致心肌梗死30min后,心肌缺血处注射壳聚糖水凝胶。术后1、2、4周,分别处死动物进行组织学、免疫组织化学检查。结果壳聚糖水凝胶注射1、2周后有明显存留,4周后已降解吸收,无明显残留,但注射后明显提高了心梗部位的心室壁厚度,梗死部位的血管密度明显增加,存活的心肌数量增多,结缔组织增生程度减轻。结论心梗部位注射壳聚糖水凝胶可明显促进血管增生,有利于梗死部位心肌细胞的存活,适宜作为可注射性组织工程化心肌的支架材料。

Objective To investigate the effect of chitosan hydrogel injected into the infarcted area of rat heart to protect the heart from infarction, so that to approach the potentiality of applying the hydrogel as scaffold material in injectable myoeardium tissue engineering. Methods 19 male Wistar rats were randomly divided into three groups： myocardial infarction （MI） group, MI＋PBS group and MI＋ chitosan hydrogel group. The left coronary artery was occluded for infarction, and 30rain later the chitosan hydrogel or PBS was injected into the infarcted area of the left ventricle respectively. 1, 2 and 4 weeks after injection, the hearts were excised and sectioned for histological and immunohistochemical detection. Results Obvious residuals may be observed at 1 and 2 weeks after chitosan hydrogel injection, while the residuals disappeared 4 weeks after chitosan hydrogel injection. However, the histological and immunohistochemical resuhs showed in the 4 weeks specimens indicated that both the thickness of left ventricle wall and the density of blood vessel increased, and the fibrosis abated compared to that in MI group and PBS group. Conclusion Injection of chitosan hydrogel into the infarcted area of the left ventricle may promote vascular proliferation and facilitate the survival of eardiomyocytes, so the chitosan hydrogel may be used as a good scaffold material in injectable myoeardium tissue engineering.