TUBULAR SCAFFOLDS WITH REDUCED SURGICAL POROSITY FOR TISSUE-ENGINEERED CONSTUCTIONS OF SMALL DIAMETER BLOOD VESSELS

Objectives: To develop a technology of formation of porous tubular scaffolds with reduced surgical porosity for tissue-engeneering constructions of small-diameter blood vessels. Methods: Frameworks in the form of 3 mm inner diameter tubes were formed by electrospinning from a 10% solution of polycaprolactone (PCL) with the addition of 5–30% gelatin (PCL-G) in hexafluoroisopropanol (voltage between electrodes 25 kV, solution flow rate 4 ml/h, distance up to the collector 100 mm, the speed of the substrate rod rotation 1000 rpm). The surface of the scaffold was coated with a bioactive coating consisting of successive layers of bovine serum albumin, heparin and platelet lysate stabilized by glutaraldehyde. Surgical porosity (SP) was measured at a pressure of 120 millimeters of mercury. Results: When applying 1 ml of PCL-G solution, the SP of scaffolds drops from 30.4 ± 1.5 ml cm-2 min-1 in the case of pure PCL to 2.8 ± 0.5 ml cm-2 min-1 at a concentration of gelatin in PCL equal to 20%. Scaffolds formed by applying 2 ml of PCL-G, regardless of the concentration of added gelatin, showed SP in the range from 1.7 to 1.9 ml cm-2 min-1. At the same time, the addition of 10% gelatin provides a defect-free surface structure both from the outer and inner sides, as well as the best mechanical properties among the samples studied (Young's modulus 6.7 ± 2.1 MPa, force to break 26.7 ± 4.9 N and elongation to break 423 ± 80%). It has been shown that a scaffold made of PCL-G and coated with a bioactive coating is able to support adhesion and proliferation of endothelial cells of the EA.hy926 line. Conclusions: PCL-G scaffolds treated with a bioactive coating is a potential candidate for the formation of a tissue-engineered design of a prosthesis for small-diameter blood vessels.