Mesoporous silica nanoparticles (MSNs) have been proven to be effective drug carriers for oral delivery. However, little attention has been paid to their in vivo biodistribution and toxicity after oral administration. The effect of particle shape on their in vivo behavior is also unknown. In this study, we systematically studied the acute toxicity and biodistribution of three types of MSNs with aspect ratios (ARs) of 1, 1.75 and 5 after oral administration. The effect of particle shape as a key physicochemical parameter of MSNs was discussed. With the increase of AR, MSNs showed decreased in vivo biodegradation, systematic absorption and excretion, especially decreased liver distribution and urinal excretion. During the period of urinal excretion, MSNs induced a shape-dependent renal damage including hemorrhage, vascular congestion and renal tubular necrosis. These findings will enrich the knowledge to rationally engineer bionanomaterials, and bring new insights into nanotoxicity. 

Nanomedicine, 2015