Modern biomedical science is challenged to develop new wound healing drugs. The collagen-containing wastes of leather industry could be the rich source of collagen products for further use in biomedical science. The aim of this research was to find the best source of collagen between limed pelt, delimed pelt and fleshings of cattle hides, and to prepare it for the use as a matrix for further microbiological studies. Collagen was extracted with 0.5 M acetic acid and 5 mM EDTA. The purity of the extracted collagen was checked by gel-electophoresis (SDS-PAGE). The rate of growth and crystal violet assay of laboratory strains (S. aureus, P. aeruginosa) were used for microbiological evaluation of obtained collagen matrices. The delimed pelt provided the highest concentration of collagen and the greatest volume of collagen products. All obtained collagen products were applicable as matrices for microbial cells growth. The applicability of collagen products from leather industry wastes for biomedical studies in Ukraine was shown.

Collagen and its derivates are typically obtained by extracting them from fresh animal tissues. Lately, however, there has been an increased interest in obtaining collagen from other sources, such as waste material, because of the growing trend to replace synthetic materials with sustainable, natural counterparts in various industries, as well as to ensure a rational waste revalorization. In this paper, collagen was obtained from non-tanned waste of leather production, taken at different stages of the production process: limed pelt, delimed pelt, and fleshings. A stepwise extraction through acid hydrolysis in 0.5 M acetic acid and subsequent precipitation with NaCl lead to collagen-containing protein extracts. The highest collagen yield was achieved in extracts based on delimed pelt (2.3% m/m after a first extraction round, and an additional 1.4% m/m after the second round). Hyp/Hyl molar ratios of 10.91 in these extracts suggest the presence of type I collagen. Moreover, gels based on these collagen extracts promote adhesion and spreading of HEK293 cells, with cells grown on collagen from delimed pelt showing a larger nuclear and cell expansion than cells grown on traditional bovine tendon atelocollagen. This suggests that these collagen gels are promising natural biomedical carriers and could be used in a wide range of medical and cosmetic applications.

The work is focused on obtaining hybrid pigments by adsorption of anionic dyes on positively charged montmorillonite. Modification of the sodium form of montmorillonite by chromium hydroxocomplexes was provided to ensure effective adsorption of anionic dyes on the surface of mineral particles. A high level of adsorption of anionic dyes as a result of steric factor was revealed. It was shown that the adsorption of dyes depended on the pH of the medium and was characterized by a maximum level at pH 4.5 – 6.0. The scheme of obtaining hybrid pigments, which were characterized by good сovering ability, resistance to stratification, especially saturated and intense colour was proposed.

The article is devoted to the investigation of the efficiency of chromium-modified montmorillonite dispersions to stabilize the collagen structure of the dermis. The interaction of modified dispersions of montmorillonite with collagen of the dermis was studied with the use of IR spectroscopic studies method. The high level of absorption of chromium compounds and their reduction by 30 % in the exhaust fluid was found. The use of montmorillonite dispersions provides qualitative formation of the structure of the dermis and physical and mechanical properties, with a reduction of tanning agents’ costs/waste by 16 %.

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