Smaller silica nanorattles reabsorbed by intestinal aggravate multiple organs damage.

Recent advances in design and controllable synthesis of rattle-type silica nanoparticles have led to a dramatic expansion of their potential drug delivery application. However, the relationship between physico-chemical parameters and bio-effects of silica nanoparticles is still unclear. In the present study, we investigated the effect of particle size on acute toxicity caused by intravenously administered silica nanorattles (SNs) in vivo. Above all, we found that SNs with smaller size may have higher toxicity potency. SNs sized 60 nm but not the others induced multi-organs structural damages, such as necrosis, congestion and haemorrhage. Interestingly, the different feeding mode after the fasted treatment induced the divarication of toxicity of 60 nm SNs. Smaller particles induced mortality even at 100 mg/kg dose injection when mice fasted for 12 hours and instantly replenish food. But no death had happened when mice received food with gradually recovery after the same treatment. The results indicate that smaller SNs drained into the intestinal tract with the bile liquids from liver may be reabsorbed into the blood through the impaired intestinal barriers and induce worse re-injure. These findings may provide useful information for the further toxicity and biodistribution research of nanoparticles.