Angiogenic vitalization of biocompatible and biodegradable scaffold (in vivo experimental study)

The aim of the study was to evaluate the effect on angiogenesis of a biocompatible, biodegradable material-derived scaffold implanted into rats and functionalized using a plasmid with a vascular growth factor gene. Methods. Experiments were performed on 24 female Wistar rats aged 2 months weighing 180—200 g. We investigated 1 cm x 1 cm flat scaffolds obtained by electrospinning from polycaprolactone functionalized scaf folds with a VEGF-165 plasmid (gene ther apy drug, Neovasculgen) incorporated in side the fibers at two concentrations, low (0.005 mg/ml) and high (0.05 mg/ml). The sample and control were simultaneously implanted subcutaneously into two formed symmetrical pockets in the interblade zone. At 7, 16, 33, 46, and 64 days, the scaf folds were re moved, and histological examination was performed; the tissue reaction was stud ied in clud ing morphometric evaluation of density and diameter of blood vessels in the implantation area, and the area of the image occupied by the material was measured. Results. Tissue rejection was absent after implantation of either control or modified material. When the material was exposed in vivo, besides resorption of the material, blood vessel number and diameter changed. As the Neovasculgen concentration in samples in creased, a dose-dependent effect of angiogenesis stimulation became evident. Vascular density was increased by 46% (high concentration, 33 days) in functionalized matrices compared to the control. After cessation of the drug treatment, the vascular density approached the control values. Conclusion. The developed technique for functionalizing polymeric scaffolds by administra tion of a solution of the gene therapy drug, Neovasculgen, into microfibers provides a prolonged and dose-dependent effect on growth of blood vessels in the implantation zone