https://doi.org/10.33573/ujoh2020.01.023
SI “Kundiiev Institute of Occupational Health of the NAMS of Ukraine, Kiev
Introduction. The contact with iron oxide nanoparticles (Fe2O3 NPs) and their entry into the human body can occur at enterprises of mining and metallurgical industries, where they are present in the composition of the condensation aerosol, as well as when using artificially synthesized NPs in medicine and pharmacology. The danger of exposure to Fe2O3 NPs for a living organism is associated with their specific physicochemical properties. The problem of the effect of Fe2O3 NPs on workers when enter the body through the intact skin remains unexplored. This determines the actuality and the need of complex morphological studies of the skin in experimental conditions.
Purpose of the study. Study of morphological changes in the skin of rats with prolonged action of Fe2O3, NPs of 19 nm and 75 nm on the intact surface.
Materials and methods. Object of the study – NPs of iron oxide and male Wistar rats (n = 24), distributed into 3 groups (1 control and 2 experimental).
In the experiment, colloidal solutions of iron oxide (Fe2O3) with nanoparticles of 19 nm and 75 nm in size were used. Morphological studies of the skin were carried out using generally accepted and special histological and histochemical methods, as well as a statistical analysis of the results.
Results of the studies. It was found that prolonged application of colloidal solutions of Fe2O3 nanoparticles of 19 nm and 75 nm onto the skin of rats caused morphological changes in all layers of the epidermis (horn, granular and basal) and in various structures of the dermis (blood capillaries, collagen and muscle fibers, hair follicles, sebaceous glands). It should be mentioned, that small NPs (19 nm) in comparison with large ones (75 nm) most often were found in the cytoplasm of the cells of epidermis and dermis. This caused more pronounced structural changes. Conclusion. Nanoparticles of iron oxide (Fe2O3 of various sizes) with prolonged application to the intact skin caused morphological changes in all layers of the epidermis, pointing to disorders in the process of keratinization. Thickening or thinning of the stratum corneum and its stratification or edema are associated with the thickness of the granular layer and the presence of keratogialin granules in it. The characteristic changes in the dermis were edema and swelling of fibrous structures, endothelium of blood vessels, hair follicle. The presence of morphological changes is the result of the effect of small granular dense inclusions on the cells of epidermis and dermis structures, the detection of which is performed due to their affinity for proteins and their ability to interact with them. The established structural changes point to changes in the barrier properties of the skin and give grounds to speak about possible ways of penetration of nanoparticles into the body. More characteristic features of structural changes are determined by the action of NPs of 19 nm.
Key words: nanoparticles, iron oxide nanoparticles (Fe2O3 NPs), skin, epidermis, dermis, horn scales, basal keratinocytes, fibers (collagen, muscle)
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