Implantation of a Poly-L-Lactide GCSF-Functionalized Scaffold in a Model of Chronic Myocardial Infarction

A previously developed poly-L-lactide scaffold re- leasing granulocyte colony-stimulating factor (PLLA/GCSF) was tested in a rabbit chronic model of myocardial infarction (MI) as a ventricular patch. Control groups were constituted by healthy, chronic MI and nonfunctionalized PLLA scaffold. PLLA-based electrospun scaffold efficiently integrated into a chronic infarcted myocardium. Functionalization of the bio- polymer with GCSF led to increased fibroblast-like vimentin- positive cellular colonization and reduced inflammatory cell infiltration within the micrometric fiber mesh in comparison to nonfunctionalized scaffold; PLLA/GCSF polymer induced an angiogenetic process with a statistically significant increase in the number of neovessels compared to the nonfunctionalized scaffold; PLLA/GCSF implanted at the infarcted zone induced a reorganization of the ECM architecture leading to connective tissue deposition and scar remodeling. These findings were coupled with a reduction in end-systolic and end-diastolic vol- umes, indicating a preventive effect of the scaffold on ventricu- lar dilation, and an improvement in cardiac performance.