Особенности получения привитого сополимера метилметакрилата на тресковый коллаген в присутствии персульфата аммония

Abstract

Restoration of damaged tissues remains a serious problem of modern medicine, which stimulates the constant development of innovative biomaterials. The presence of a large amount of waste during the processing of marine products, primarily collagen sources, has become an important incentive for the development of research on the use of natural polymers for medical purposes. The serious advantages of marine collagen are well-known facts. In particular, many animals are susceptible to certain diseases that can be transmitted to humans, and the use of animal-derived collagen has religious and ethical restrictions. At the same time, fish collagen is similar in nature to human collagen. Research by many scientists has shown that fish collagen is a good base of materials for wound coverings and scaffolds, in fact, a trend of exploratory research in recent years. However, it requires modification to create a stable three-dimensional structure. In previous studies conducted by the authors of this paper in an inert atmosphere under conditions of visible light photocatalysis in the presence of a complex oxide RbTe1.5W0.5O6 in an aqueous dispersion of cod collagen and methyl methacrylate with modifiers – biodegradable polymers – hydrogels of stable three-dimensional structure were obtained. Sponge-plates based on them have shown high efficiency in wound healing tests on small animals (rats). Under these specified conditions, hydroxyl radical is formed in the polymerizate; their interaction with the organic substrates in the reaction mixture leads to the formation of stable three-dimensional structures – the hydrogels described previously. In this work, new graft copolymers polymethylmethacrylate-cod collagen were obtained as the basis of wound coatings, using ammonium persulfate - ascorbic acid, a source of hydroxyl radicals, as the initiator of the redox system. The analysis of their most important characteristics in terms of the development of hydrogels was carried out: molecular weight, collagen content, morphology. Thus, the nitrogen content in the graft copolymer after synthesis significantly decreased in comparison with the initial collagen sample and amounts to ~12%, as was the case during photocatalysis. An analysis of the molecular weight characteristics of the polymer synthesis product solution by the GPC method showed that the solution of the copolymer obtained with the initiator ammonium persulfate - ascorbic acid, unlike the copolymer during photocatalysis, has a separate high-molecular mode (Mn values ~ 1000 kDa). In the case of photocatalysis, the MWD curve of the initial collagen polymer shifted towards higher molecular weights. The SEM analysis allowed us to establish morphological differences between the original collagen and the grafted copolymer, indicating the inclusion of synthetic polymer fragments in the fibrillar organization of collagen. Thus, freeze-dried collagen samples have clear outlines of collagen fibers and formed pores, while the images of the grafted copolymer sample clearly show a more complex structurally relief organization between the collagen fibers, very similar to that for the copolymer obtained under photocatalysis conditions. The identified characteristics of the PMMA-collagen graft copolymer, obtained by initiation with ammonium persulfate – ascorbic acid, provide a basis for conducting research on producing a hydrogel from it by introducing modifying and crosslinking agents and the use it in regenerative medicine.