Myocardial infarction and the subsequent heart failure remain among the world’s prominent health challenges. Other studies have demonstrated that bio-derived materials improve cardiac function after implantation for angiogenic potential. In this study, we hypothesized that injection of biomaterials into infarcted myocardium can preserve left ventricle (LV) function through its prevention of paradoxical systolic bulging. Infarction was induced in rabbit myocardium by coronary artery ligation. In sham-operated rabbits (n = 5), a suture was tied loosely around the left anterior descending coronary artery without ligating it. 7 dayslater, 100μl α-cyclodextrin (CD) solution and 100μl poly (ethylene glycol)-b-polycaprolactone-(dodecanedioic acid)-polycaprolactone-poly (ethylene glycol)(MPEG-PCL-MPEG) solution (n = 7) was injected simultaneously through Duploject applicator into the infarcted myocardium. Solid hydrogel matrix formed by linear MPEG-PCL-MPEG polymer threading into the cavities of the α-cyclodextrin after mixing. Injection of phosphate buffered saline (PBS) served as controls (n = 7). 28 days after the treatments, histological analysis indicated that injection of hydrogel prevented scar expansion and wall thinning compared with group (
P
< 0.05) without more microvessel density in infarcted myocardium (
P
= 0.70).By echocardiography, LV ejection fraction was significantly greater in the hydrogel group (56.09 ± 8.42%) than the control group (37.26 ± 6.36%,
P
= 0.001). The LV end-diastolic and end-systolic diameters were 2.07 ± 0.33 cm and 1.74 ± 0.30cm in the control group, respectively. Smaller LV end-diastolic diameter (1.61 ± 0.26cm,
P
= 0.005) and smaller end-systolic diameter (1.17 ± 0.23cm,
P
= 0.001) were found in the hydrogel group. These results suggest that α-CD/MPEG-PCL-MPEG hydrogel injection could serve structural and mechanical support of an injured LV replacing some of the functions of the damaged ECM and thus prevented paradoxical motion serves, which may eventually lead to LV remodeling and dilation prevention. Our study should initiate further experimental and clinical studies exploring potential approaches to the treatment of postinfarction heart failure.
Permanent Ligation of the Left Anterior Descending Coronary Artery in Mice: A Model of Post-myocardial Infarction Remodelling and Heart Failure
