Effect of gold nanoparticles shape and dose on immunological, hematological, inflammatory, and antioxidants...

Gold nanorods (AuNRs) have gained much attention recent years due to their promising optical and chemical properties and are hence used in applied research and industrial nanotechnology. This study was designed to investigate the effect of gold nanoparticle shape (Gold nanorods vs. gold nanosphere) on immune response in rabbit.

Thirty New Zealand white rabbits were divided into six groups (n=5 rabbits). The first group is the control negative received an intravenous (IV) injection of normal saline 0.9%; the second group (vaccinated) is the control positive, and the other four groups were vaccinated and received a single-dose or repeated five consecutive IV doses of 300 mg/kg body weight 50 nm AuNRs or 50 nm gold nanosphere (50 nm AuNSs) dissolved in ultrapure water. Blood and serum were collected for the hematological and biochemical analysis.

White blood cells (WBCs) count, lymphocytes, monocytes, eosinophils, and basophils showed significantly (p<0.05) higher values with the repeated-dose AuNRs. g-globulin levels showed a significant difference after 15 days in the single-dose AuNSs. Single-dose AuNSs significantly (p<0.05) increased the immunoglobulin G (IgG) and significantly (p<0.05) decreased the tumor necrosis factor-alpha. In addition, it elicited a significant (p<0.05) decrease in the malondialdehyde levels and a significant (p<0.05) increase of the superoxide dismutase, glutathione peroxidase, and catalase levels. Moreover, evoked red blood cells count, mean corpuscular volume, and mean corpuscular hemoglobin were significantly (p<0.05) lower than the control group. The platelet count, lysozymes, and nitric oxide were significantly (p<0.05) higher in repeated-dose AuNRs.

The effect of AuNPs is shape and dose-dependent. The repeated 5 days IV 50 nm AuNRs doses over 15 days showed a significant antioxidant effect, with no considerable toxicity or vascular reactions.