The toxic effects of silver nanoparticles of different sizes on the submandibular salivary gland of adult albino rats : Animal study / Marwa Elsaeed Ahmed Mohamed Elnashar ; Supervised Nahed Sedky Korany , Bassant Adel Ezzat

Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Oral Biology

Background: Silver nanoparticles became one of the most manufactured nanomaterials introduced in the medicine field, that{u2019}s why it was mandatory to evaluate their biological toxicity.Aim of the study: In this study, the aim was to evaluate the size-dependent toxicity of intraperitoneal administered characterized Ag NPs of different sizes on the submandibular salivary glands of adult albino rats.Methodology: Fifty adult male albino rats were randomized into three groups: group 1 (control), group 2 received intraperitoneal injection of 13mg/kg body weight of Ag NPs (10 nm), and group 3 received intraperitoneal injection of 13mg/kg body weight of Ag NPs (60 nm).The rats were sacrificed after 3 and 6 hours from treatment.The submandibular salivary glands of the all groups were subjected to histopathological examination, histomorphometric analysis,immunohistochemical examination, real time PCR analysis, colorimetric assay, and ultrastructural examination.Results: Histologically, the submandibular salivary glands of group 2 revealed sign of acinar degeneration, represented by loss of normal architecture (amalgamation), intracytoplasmic vacuolization. The nuclei of the acinar cells revealed pleomorphism and pyknosis. However, the seromucous acini were relatively preserved their shape in group 3. Immunohistochemical examination showed significant increase in active caspase-3 immunoreactivity in all Ag NP-treated groups. RT-PCR results revealed significantly decreased GPx mRNA gene expression in all Ag NP- treated groups, while colorimetric assessment revealed significantly decreased GSH levels and increased MDA levels in all Ag NP-treated groups

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