METHOD OF FORMING PREFABRICATED UNITS USED IN PRODUCTION OF SYSTEMS OF PROSTHETIC AORTIC VALVE TRANSCATHETER IMPLANTATION AND PROSTHETIC AORTIC VALVE PREFABRICATED UNIT

摘要

A method of forming prefabricated units used in production of systems of prosthetic aortic valve transcatheter implantation and prosthetic aortic valve prefabricated unit with an non-thrombogenic smooth surface layer or with a porous fibrous layer constituting a scaffold for epithelium cell culture, intended for manufacturing TAVI system. Stents for covering and solutions of polycarbonate silicones and/or polycarbonate urethanes and/ or polyurethane with average molecular weight in the range from 50 000 g/mol to 200 000 g/mol in the solvent DMAC are prepared. Initially a smooth layer of polycarbonate silicone is applied in the electrosponning machine by electrospraying with use of the solution in DMAC with the concentration of 2-8% w/w. and/or a fibre of polycarbonate urethane is applied by electrospinning on the roller with use of the solution in DMAC with the concentration of 8-20% w/w to obtain the first surface layer, with a specified speed, number of heads, thickness of capillaries, speed of movement, voltage and distance between the capillary and the roller and the specified flow of the solution on the feeding pump and after a certain time the layer covering the roller with thickness of 1-100 µm is obtained. Thereafter the inner intermediate layer of polycarbonate silicone is formed by electrospraying. When the thickness of the layer is approximately 5 to 100 µm the process is stopped and stents are placed on the formed layer and similarly like applying the former intermediate layer the application of the inner intermediate layer is continued on the whole length of the roller. Thereafter the final surface layer is applied like the first surface layer until a prefabricated unit with the polymer material thickness from 50 to 250 µm is obtained.