THE STUDY OF SILVER NANOPARTICLE EXPOSURE ON ORGAN PATHOLOGY IN SPRAGUE-DAWLEY RATS

Silver nanoparticles (AgNPs) have potent physical, chemical and antibacterial properties, which has lead to their application in a wide variety of industrial and medical products. This study investigated the toxicity, distribution, and accumulation of AgNPs in the digestive tract, liver, spleen, brain, and bone tissue of female Sprague-Dawley rats. In addition, the effect of Ag ions was also examined. The experimental specimens were exposed to AgNPs synthesized using cetyltrimethyl ammonium bromide (CTAB) as a stabilizer through the reduction of silver nitrate (AgNO₃) with sodium borohydride (NaBH₄) in water. The solutions were administered orally in water for an 18-day period. The following treatments were established: colloidal AgNP 20 ppm daily, silver ions (Ag⁺) from silver nitrate (AgNO₃). The following controls were prepared: 20 ppm CTAB control and tap water. During the experiment behavioral observations were conducted. At the termination of the experiment, the rats were sacrificed by CO₂ overdose and organs were collected for further analysis. Throughout the experimental exposure, the rats receiving the AgNPs became visibly more lethargic, their fur coat lost its luster, and the animals shed their fur in tufts, displaying alopecia. Dark gray circles lining their eyes also developed and one rat exposed to AgNPs had a deformation in the size of the eye. Significant time difference between treatments was observed during the euthanasia process. The rats exposed to the AgNPs treatment died in approximately 20-30 seconds, 1 minute in AgNO₃, and 2 minutes in CTAB while the tap water control had a lethal exposure of 3-4 minutes. Rats in AgNP treatment had visible hepatomegaly and splenomegaly. AgNP rats had fragile veins that were bursting when attempting blood collection pre-mortem and extremely brittle bones that were breaking and cracking after applying minimal pressure, showing signs of osteoporosis. Hematological analysis indicated that the AgNP rats had the highest number of lymphocytes, displaying lymphocytosis and a significantly lower amount of neutrophils and monocytes, showing neutropenia and monocytopenia. The gross observations suggest that the administration of AgNP’s orally had an adverse effect on the health and systematic functions of Sprague-Dawley rats.