Pre-Treatment with Zirconia Nanoparticles Reduces Inflammation Induced by the Pathogenic H5N1 Influenza Virus

Huo, Caiyun; Xiao, Jin; Xiao, Kai; Zou, Shumei; Wang, Ming; Qi, Peng; Liu, Tianlong; Hu, Yanxin

The effect of surface charges of NPs on their antiviral efficacy was studied using 200 nm NPs with positive and negative charges. ZrO 2 , SNs, and PS NPs with both charges were administered to H5N1-infected mice at 100 mg/kg. As shown in Figure 2B and Figure S1B , compared to the glucose group, in which 4 of 7 mice died, only one mouse died in the group treated with positive NPs. The survival rate of mice in the glucose group was 42.9%, while the P-ZrO 2 and N-ZrO 2 groups had survival rates of 85.7% and 57.1%, respectively. No significant differences were found between glucose and negatively-charged NPs in terms of death rate. These results show that positively-charged NPs confer a higher survival rate and constant body weight, thereby providing enhanced protection against H5N1. Numerous studies have discussed the relationship between NP physicochemical properties and their biological effects. 39, 40 Some reports have shown that particle size plays an important role in the biological effects of NPs, including cellular uptake and toxicity. 41 Size plays a key role in the physiological response, bio-distribution, and elimination of various materials. 42 Furthermore, surface modification of NPs is critical, as it may lead to altered cellular uptake and endosomal escape of NPs. Lin et al reported that particle uptake by cells increased following the same trend as their surface charges. 43 The results of the present study suggest that positively-charged NPs of the appropriate size have a stronger antiviral effect against H5N1 compared to negatively-charged NPs.