The Review of Small Size Silver Nanoparticle Neurotoxicity: A Repeat Study

Abstract

Repeated oral gavages silver nanoparticle colloidal solution ingestion procedures for AgNps neural toxicity have been investigated in Swiss albino mouse fetuses’ brain at the ultra-structural (TEM) level by transmission electron microscopy and Nikon bright field microscopy. Transmission electron microscopy probe identified neural toxicity in the brain of mice fetuses in the form of mitochondrial autophagy, dysmorphology & dysfunction of cellular organelles vacuolization of neuronal cell, blood brain barrier inflammation, astrocytic swelling, Gliosis and a well visualized differentiation to the reaction products. Multiple reaction product localization was visible in the form of smaller size silver nano particles (1 to 20 nm range) percolation and perimembranous multiple patchy condensations focuses appeared from inside and outside of neuronal cell membrane. Histologically cell and tissue dysmorphology was observed in the form of unipolar brush cell and lugaro cells degeneration with dysmorphology of corticomedullary layers of cerebrum, cerebellum and hippocampus. In twice, lower dose (0.5 and 1 mg/kg b.w./ day) and higher dose (10 and 15 mg/kg b.w./day) small size silver nano particles were found adhered both side of cell membrane, mitochondria and endocytotic vesicle. Neural histochemistry of fetal cortex by Golgi staining procedure showed reduction number of dendrite arborisation and unipolar neuron with basket cells degeneration and dysmorphology. But the intensity of such was found almost low or equal to control in lower dose and high in higher dose and concentration. Small size silver nano particles exhibits more neurotoxic effect comparatively to other metal nanoparticles because of easy penetration and disintegrity to BBB.