| Abstract [eng] |
Cardiovascular diseases promote health risks that are a major problem worldwide. Successful treatment of these diseases can be achieved through the use of advanced engineering technologies aimed at producing value-added scaffolds that promote tissue or organ regeneration. To achieve this goal, universal electrospinning technology is used. During electrospinning, fibrous scaffolds are formed from polymer solutions that can replicate the extracellular matrix of natural blood vessels. It has been observed that a great deal of attention has recently been paid to the combination of different polymers in order to improve the properties of one polymer using other polymers. Therefore, alternative polymer blends are being sought that are suitable for the production of constructs for vascular regeneration to improve chemical, biological and physical properties of the resulting scaffolds. The final master's project is designed to create and study constructs for blood vessels regeneration using chemical, mechanical and physical methods. The study investigated the possibility of mixing different polymers and the application of such mixtures in the process of electrospinning. The object of this project was constructs obtained by electrospinning using solutions of polycaprolactone (PCL) / gelatin and PCL / polyvinylpyrrolidone (PVP) with different mixing ratios. During the research of the master's project the structure and properties of the formed constructs by electrospinning were analyzed. Scanning electron microscopy revealed that scaffolds consisted of randomly oriented micro-nano fibers. The addition of PVP or gelatin in the polymer blend had a positive effect on the structure of the scaffold, as denser fibers mats with uniform fibers were formed during electrospinning. It was estimated that increasing the concentration of PVP and gelatin additives had an effect on the diameter of the fibers and pores. It was found that the median diameter of the fibers of the constructs with PVP additive ranged from 0,43 μm to 1,99 μm, in the case of gelatin – from 0,24 μm to 1,06 μm. During thermal analysis weight loss was observed in the scaffolds with gelatin additive in the temperature range of 100–432 ºC, with PVP additive in the temperature range of 353–466 ºC. FT-IR analysis revealed that the constructs had PCL, gelatin and PVP specific functional groups. Water contact angle study showed that the addition of PVP or gelatin in the polymer blend had a positive effect on the surface properties of the constructs. Increasing the gelatin additive concentration was found to be the most effective as the water contact angle decreased from 111º to 23º. Tensile tests of the products showed that scaffolds formed from a pure PCL solution with a tensile strength of 3,36 MPa had the best mechanical tensile properties. It was observed that by increasing the concentration of PVP and gelatin additives, the tensile strength of the constructs decreased 1,4 and 1,7 times, respectively. Based on the obtained results, recommendations for the industrial production of constructs were provided. |
