Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies.

Objective: To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process.
Methods: Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations.
Results: Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point.
Conclusion: Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.