In vivo biodistribution and urinary excretion of mesoporous silica nanoparticles: Effects of particle size and PEGylation

The in vivo biodistribution and urinary excretion of spherical mesoporous silica nanoparticles (MSNs) are evaluated by tail-vein injection in ICR mice, and the effects of the particle size and PEGylation are investigated. The results indicate that both MSNs and PEGylated MSNs of different particle sizes (80-360 nm) distribute mainly in the liver and spleen, a minority of them in the lungs, and a few in the kidney and heart. The PEGylated MSNs of smaller particle size escape more easily from capture by liver, spleen, and lung tissues, possess longer blood-circulation lifetime, and are more slowly biodegraded and correspondingly have a lower excreted amount of degradation products in the urine. Neither MSNs nor PEGylated MSNs cause tissue toxicity after 1 month in vivo. The in vivo biodistribution and urinary excretion of spherical mesoporous silica nanoparticles (MSNs) and PEGylated MSNs of different particle sizes (80-360 nm) are investigated. The 1-month tissue compatibility of MSNs and PEGylated MSNs is also evaluated by histopathological examination.