“…In these studies, in which animals received microparticles through the gastrointestinal tract, it is impossible to determine whether all microparticles in the intestinal epithelium were in the process of internalization or some of them were excreted from the body. In turn, in studies of the biodistribution of microparticles injected intravenously or intraperitoneally, researchers, as a rule, focus on other organs, but not the intestine ( Kaminski et al, 2004 ; Decuzzi et al., 2010 ), or available studies are not detailed enough ( Bartholdson et al, 1977 ; Westrøm et al., 2018 ). Therefore, further research could clarify the specificity and effectiveness of observed migration of loaded phagocytes, followed by penetration of the mucosal epithelium and microparticles removal from D. rerio intestine.…”