Characteristics of interpenetrating hydrogels based on fibrin and high molecular weight polyvinyl alcohol

Aim. In an in vitro experiment, to study the properties of the IPN hydrogel fibrin/high-molecular polyvinyl alcohol with an increased number of cryocycles and fibrinogen concentrations to assess the prospects for its use in the creation of small-diameter vascular prostheses. Materials and Methods. One-component samples of fibrin hydrogels containing 40 and 50 mg/ ml fibrinogen, PVA polymer (146000-186000 Da) 30 and 40 mg/ml and the corresponding groups of IPN hydrogel samples were polymerized: fibrin 40 mg/ml and PVA 30 mg/ml (F40P30), fibrin 40 mg/ ml and PVA 40 mg/ml (F40P40), fibrin 50 mg/ml and PVA 30 mg/ml (F50P30), fibrin 50 mg/ml and PVA 40 mg/ml (F50P40). PVA was cryostructured for 5 cycles. The structural properties of the samples were studied using SEM, histological staining of sections with hematoxylin and eosin, and IR spectroscopy. Biological properties were assessed by the viability, number and metabolic activity of cells colonized on the materials. The physical and mechanical properties of the samples were characterized by tensile strength, relative elongation and Young's modulus. The hemocompatibility of materials was assessed by contact activation of platelets and the percentage of erythrocyte hemolysis. Results. Sequential polymerization of fibrin and high-molecular-weight PVA produced an IPN hydrogel with a uniform distribution of components in the thickness and lower surface, but a predominant presence of PVA on the upper surface. The structural heterogeneity of the material affected the biological properties. The lower surface of IPN hydrogels showed higher biocompatibility compared to the upper surface. The strength of IPN hydrogels increased with increasing PVA molecular weight, concentration and number of cryocycles, but did not reach a. mammaria. Hydrogels do not hemolyze red blood cells and do not activate platelets. Conclusion . Using a technique of sequential polymerization of fibrin and high molecular weight PVA over five cryocycles, a double-sided IPN hydrogel with high biocompatibility on the lower side and improved strength was obtained. However, the physical and mechanical characteristics of IPN hydrogel were weaker than a. mammaria, which requires new solutions.