[Effect of a novel injectable hydrogel implant on ventricular remodeling in rabbits with experimental myocardial...

To observe whether injectable hydrogel implantation could prevent adverse cardiac remodeling and preserve cardiac function in rabbits with myocardial infarction (MI).

A novel injectable hydrogel, the copolymer MPM/alpha-CD, which self-assembled between alpha-cyclodextrin and methoxy polyethylene glycol-poly (caprolactone)-(dodecanedioic acid)-poly (caprolactone)-methoxypolyethylene glycol triblock polymer, was synthesized by chemical crosslinking and characterized by biocompatibility and biodegradability. Experimental MI was induced in male rabbits by coronary artery ligation. The MI rabbits were randomly divided into hydrogel group (200 microl MPM/alpha-CD were injected into the infarcted myocardium 7 days after MI) and control group (equal volume phosphate buffered saline myocardial injection, n = 8 each). Four weeks after MPM/alpha-CD implantation, echocardiography, histochemistry and immunohistochemistry were performed.

Left ventricle ejection fraction was significantly improved in the hydrogel-treated group (56.1% +/- 8.4%) than that in the control group (37.3% +/- 6.4%, P < 0.05). Histological analysis indicated that hydrogel degraded 4 weeks after hydrogel injection, and prevented scar expansion and wall thinning [(3.08 +/- 0.32) mm vs. (2.18 +/- 0.46) mm in control group, P < 0.05]. Neovasculature formation was similar between the hydrogel group [(100.8 +/- 2.4)/mm(2)] and the control [(98.5 +/- 2.9)/mm(2), P > 0.05].

MPM/alpha-CD could serve as an excellent injectable biomaterial for improves cardiac function and attenuating scar expansion and left ventricular dilation in MI rabbits.