Construction of the myocardial ischemia-reperfusion injury model in mice

Six C57BL/6 mice were anesthetized with isoflurane and ventilated by a rodent ventilator. The thoracic cavity was opened around the fourth rib space, and the left anterior descending coronary artery was ligated. After 45 min, the ligation was stopped for reperfusion to construct the animal model of myocardial ischemia-reperfusion injury. The mice were randomly allocated to two groups, an MSC-EXO group and a PBS group. Mice in the MSC-EXO group (n=3) were injected with 25 µL PBS and 50 µg MSC-EXO into three myocardial tissue regions. Mice in the PBS group (n=3) were injected with 25 µL of PBS into three myocardial tissue regions. A further three C57BL/6 mice were allocated as the control group and underwent thoracic surgery after anesthesia, but the left anterior descending coronary artery of this group was not ligated. All mice were kept in a laboratory with a suitable temperature and humidity and had free access to food and water under a 12-h dark/light phase condition.