Biodistribution and excretion of colloidal gold nanoparticles after intravenous injection: Effects of particle size

BACKGROUND: Inorganic gold nanoparticles (NPs) have a huge potential in targeted drug delivery. Simple preparation and surface modification procedure with their special physicochemical properties of gold NPs attract their use such as tumor targeting and the detection of cancerous cell. OBJECTIVE: Various studies were reported, however, details of biodistribution profile of gold NPs were not enough evaluated. We have studied biodistribution profile of gold NPs having various particle sizes (20, 50 and 100 nm). METHODS: Gold concentrations in brain, heart, lungs, liver, stomach, pancreas, spleen, kidneys, blood, urine, and feces were measured at 5 minutes, 0.25, 0.5, 1, 2, 3, 6, 12, 18 and 24 hours after administration of gold NPs using inductively coupled plasma atomic emission spectrometry. RESULTS: In lungs and brain, especially 20-nm gold NPs were accumulated after 2-3 hours of dose administration, and they were kept for 24 hours, whereas they showed relatively low accumulation in heart, stomach and pancreas. After 12 hours, 3.3-14.4% of the injected gold were observed in fecal matter and urine. CONCLUSIONS: From this study, the application of gold NPs for targeted delivery to lungs and brain and the excretion route of the gold NPs from the body were suggested