FEATURES OF POLYURETHANE MATRIX REMODELING IN SHEEP MODEL EXPERIMENTS

Abstract

HighlightsThe article describes the features of remodeling of polyurethane matrices during long-term implantation into the vascular bed of sheep. The results indicate high biocompatibility of polyurethane and resistance to bioresorption. The obtained data are significant for the development of medical products for cardiovascular surgery, in particular, biodegradable vascular prostheses. AbstractAim. To evaluate the features of polyurethane remodeling in a long-term experiment on a large animal model.Methods. Matrices made of 12% polyurethane solution in chloroform were manufactured by electrospinning at the Nanon-01A nanofiber electrospinning system (MIC, Japan). Matrix samples in the form of patches were implanted into the carotid arteries of sheep (n = 3) for a period of 6 months. The patency of vessels with implanted matrices was assessed after 2, 4 and 6 months using a portable hand-carried color Doppler - M7 Premium Ultrasound Machine (Mindray, China). The structure of the matrix surface before and after implantation was studied using an S-3400N scanning electron microscope (Hitachi, Japan). Histological examination of the explanted samples was carried out using an AXIO Imager A1 microscope (Carl Zeiss, Oberkochen, Germany) with previous staining of matrix sections with hematoxylin-eosin, Van Gieson and alizarin red C. Data processing was performed using the Statistica 6.0 software.Results. After 2, 4 and 6 months of implantation of polyurethane matrices into the carotid artery of sheep, complete patency of the carotid arteries was revealed. Macroscopically, after 6 months of implantation, the matrix completely resembled the carotid artery wall due to the full consolidation of the matrix with the artery wall and remodeling. Layers of newly formed vascular tissue – neointima and neoadventitia – were formed on the basis of the matrix. Histological examination revealed the structural integrity of the matrix without signs of inflammation and calcification both in the matrix structure and adjacent tissues.Conclusion. The biological inertia of polyurethane matrices with signs of remodeling was noted, which indicates a high biocompatibility of the material. Resistance to bioresorption and the ability to keep the frame of the product for a long time allows us to consider polyurethane as a suitable material for the formation of anti-aneurysmal protection of biodegradable vascular prostheses.