4. Discussion
ZnO NPs are known to be cytotoxic and genotoxic in vitro and in vivo [9; 24-26]. However there is a lack of information where immunomodulatory effects of ZnO NPs are considered. Since, in vitro system cannot mimic the complexity of an in vivo system; hence in vivo is preferred for the toxicological evaluation. In the present study BALB/c mice were chosen as the in vivo model due to their immunocompetence and similarity with human metabolic activity, biochemical and physiological pathways [27].
Understanding the physical and chemical properties of NPs is essential to study the biological effects of the NPs [28]. The mean hydrodynamic diameter of ZnO NPs was 300.2 nm as measured by DLS and the average size calculated by TEM was ~ 20 nm. This difference in sizes is due to the different principles involved in the two measurement techniques [29].
ZnO NP treated mice were all alive during the experiment compared to control group. Moreover no statistically significant difference in b. wt. was observed between the control and treated groups. This suggests that the exposure did not lead to any major visible changes in the health condition of animals.
The immunotoxic potential of ZnO NPs in vivo was evaluated by studying the changes in the relative distribution of CD4 and CD8 T cells and cytokine release in the serum. The …show more content…
The ZnO NPs were found to have a higher percentage of accumulation in liver of aged mice after 14 day exposure. The AAS data was further supported by TEM images where ZnO NPs were observed in the cytoplasm of hepatocytes of aged mice. The deposited ZnO NPs are responsible for its induced toxicity in aged mice. The ultrastructural changes in the cells from the organs of ZnO NPs treated aged mice show the deleterious effects of NPs. Similar age dependent ZnO NP-induced neurotoxicity were obtained by Tian et al.
ZnO NPs are known to be cytotoxic and genotoxic in vitro and in vivo [9; 24-26]. However there is a lack of information where immunomodulatory effects of ZnO NPs are considered. Since, in vitro system cannot mimic the complexity of an in vivo system; hence in vivo is preferred for the toxicological evaluation. In the present study BALB/c mice were chosen as the in vivo model due to their immunocompetence and similarity with human metabolic activity, biochemical and physiological pathways [27].
Understanding the physical and chemical properties of NPs is essential to study the biological effects of the NPs [28]. The mean hydrodynamic diameter of ZnO NPs was 300.2 nm as measured by DLS and the average size calculated by TEM was ~ 20 nm. This difference in sizes is due to the different principles involved in the two measurement techniques [29].
ZnO NP treated mice were all alive during the experiment compared to control group. Moreover no statistically significant difference in b. wt. was observed between the control and treated groups. This suggests that the exposure did not lead to any major visible changes in the health condition of animals.
The immunotoxic potential of ZnO NPs in vivo was evaluated by studying the changes in the relative distribution of CD4 and CD8 T cells and cytokine release in the serum. The …show more content…
The ZnO NPs were found to have a higher percentage of accumulation in liver of aged mice after 14 day exposure. The AAS data was further supported by TEM images where ZnO NPs were observed in the cytoplasm of hepatocytes of aged mice. The deposited ZnO NPs are responsible for its induced toxicity in aged mice. The ultrastructural changes in the cells from the organs of ZnO NPs treated aged mice show the deleterious effects of NPs. Similar age dependent ZnO NP-induced neurotoxicity were obtained by Tian et al.