Abstract 1989: Transplantation of Nanoparticle Based Skeletal Myoblasts Over-Expression Vascular Endothelial Growth Factor-165 for Cardiac Repair
Objective: We investigated the feasibility and efficacy of polyethylenimine (PEI) based human vascular endothelial growth factor-165 (hVEGF165) gene transfer into human skeletal myoblasts (HSM) for cell based delivery to the ischemic myocardium in a rat heart model.
Methods: The feasibility and efficacy of PEI for gene transfer with HSM was characterized using plasmid carrying enhanced green fluorescent protein (pEGFP). PEI of 25 kDa (10mM) was proportionally mixed with pEGFP. The gene transfection efficiency was assessed by flow cytometry. Based on optimized transfection procedure, HSM were transfected with PEI carrying plasmid-hVEGF165 (phVEGF165). The gene expression mode of hVEGF165 was characterized. The genetically modified HSM was transplanted into rat heart model of acute myocardial infarction: group-1 = DMEM injection, group-2 = HSM transplantation, group-3 = PEI mediated phVEGF165 transfected HSM (PEI-phVEGF myoblast) transplantation. All animals received cyclosporine injection from 3 days before and until 4 weeks after treatment. Echocardiography was performed to assess the heart function. Animals were sacrificed for immunohistochemcial studies at 4 weeks after treatment.
Results: Flow cytometry revealed that ~11% HSM was successfully transfected with pEGFP. Based on optimized transfection condition, transfected HSM expressed hVEGF165 up to day-18 (4.47 ng/ml) with peak at day-1 (25.6 ng/ml) with > 90% cell viability. Animal studies revealed reduced apoptosis was found in group-2 and group-3 animal’s heart as compared to group-1. Blood vessel density (x100) by immunostaining for vWF-VIII in group-3 was 87.1+ 7.76 (p < 0.001) as compared to group-1 (34.2 ± 1.62) and group-2 (42.4 ± 5.92) at 4 weeks. Significantly improved blood flow (ml/min/g) of left ventricular anterior wall was achieved by group-3 (2.2 ± 0.35) as compared with group-1 (0.69 ± 0.1 p < 0.001) and group-2 (1.37 ± 0.13 p = 0.016) at 4 weeks. Improved ejection fraction was achieved in group-3 (58.44 ± 4.92%) as compared with group-1 (41.67 ± 4.77% p = 0.001) and group-2 (50.53 ± 4.73 p = 0.037).
Conclusion: Polyethylenimine mediated hVEGF165 gene transfer with HSM is a safe and efficacy alternative for angiomyogenesis for cardiac repair.