en تخصصي Special پژوهشي Research <div style="text-align: justify;"><span style="font-size:11pt"><span style="line-height:normal"><span style="unicode-bidi:embed"><span style="font-family:Calibri,sans-serif"><b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Background: </span></span></b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">As one of the most influential and in-demand nanoparticles for commercial applications, titanium dioxide nanoparticles are commonly used in industry as a white pigment, in cosmetic and health products, and as a disinfection agent. In food and drugs, this additive is known as E171 and helps define colors clearly and can prevent UV degradation. This study used light and transmission electron microscopy to examine the effects of </span></span><span lang="EN-GB" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">titanium dioxide nanoparticles </span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">on the liver in rats.</span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span style="unicode-bidi:embed"><span style="font-family:Calibri,sans-serif"><b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Methods: </span></span></b><span lang="EN-GB" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Titanium dioxide nanoparticles were administered to 40 rats at 0, 10, 20, and 50 mg per kilogram of rat body weight suspended in one millilitre of distilled water over 60 days (every second day) by oral gavage.</span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">The rats were euthanized and tissue samples were dissected from the liver for light (thick section)and transmission electron (thin section) microscopy study.</span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span style="unicode-bidi:embed"><span style="font-family:Calibri,sans-serif"><b><span lang="EN-GB" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Results: </span></span></b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Histopathological examinations in treated groups revealed dilation of hepatic sinusoids, hepatocytes degeneration and necrosis, observed as cellular swelling, cytoplasmic vacuolation, and loss of nuclei, nuclear pyknosis, karyorrhexis, and karyolysis</span></span><span lang="EN-GB" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">. Some pathologic changes were also observed in mitochondria; the enlargement of the mitochondrial membrane and cristae, the disintegration of the mitochondria, and the destruction of the cristae were evident in response to all doses utilized in the study.</span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span style="unicode-bidi:embed"><span style="font-family:Calibri,sans-serif"><b><span lang="EN-GB" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Conclusions: </span></span></b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Our studydemonstrated that the continuous use of titanium dioxide nanoparticles(E171) can cause histopathological damages in the liver and disrupt the function of this organ. Consequently, it is recommended to limit the use of this ingredient in industrial, sanitary, foods, and cosmetic products.</span></span></span></span></span></span><br> &nbsp;</div> Electron microscopy, Hepatocytes,Histology, Nanoparticles, Titanium dioxide 233 240 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-1277-2&slc_lang=en&sid=1 Roozbeh Choobchian 100319475328460016870 100319475328460016870 No Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Ahmadreza Raji rajireza@um.ac.ir 100319475328460016871 100319475328460016871 Yes Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Hossein Nourani nourani@um.ac.ir 100319475328460016872 100319475328460016872 No Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Amir Moghadam Jafari moghaddamjafari@um.ac.ir 100319475328460016873 100319475328460016873 No Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Arezo Moghtadari Esfahani a.m.esfahani92@gmail.com 100319475328460016874 100319475328460016874 No Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran