Systems Nanotoxicity Of Mesoporous Silica Nanoparticles

Mesoporous silica nanoparticles(MSNs)are widely used in the field of biomedicine due to their characteristics of controllable morphology,adjustable pore size,highly specific surface area,easy-to-modify surface and good biocompatibility.The main ways for MSNs to enter the body include tracheal instillation,gavage and intravenous injection,etc.However,there are few comprehensive studies on the nanotoxicity of MSNs and the influence of MSNs on cell metabolism in cells,which greatly limits the clinical application of MSNs.Therefore,in this paper,by synthesizing MSNs with different particle sizes and using multi-omics method,the nanotoxicity of MSNs was systematically studied,which provide theoretical basis and scientific basis for the safe application of MSNs in the future.The main contents of the paper are as follows:(1)Taking ICR mice as a model,three kinds of MSNs of 30 nm,80 nm and 200 nm were acutely instilled through the trachea.The results showed that MSNs with three particle sizes were mainly accumulated in the lung organs,and the surface active substances secreted by the lung were greatly promoted which greatly reduced the toxicity of MSNs.Through PCA and PLS-DA analysis,80 nm MSNs showed the least hepatotoxicity,30 nm MSNs showed the lowest hepatotoxicity,and 200 nm MSNs showed the highest hepatotoxicity.Through the determination of ALT/AST liver function indexes,it is clear that 200 nm MSNs caused abnormal liver function.Through metabolomics method,it was confirmed that 200 nm MSNs could induce enhanced hepatic gluconeogenesis to increase renal urea,and at the same time caused renal metabolic disorder,strengthened energy metabolism cycle,promoted inflammation and antioxidant pathway,enhanced gluconeogenesis,and induced renal tubules to secrete ammonia.This work showed that 30 nm and 80 nm nanoparticles are biosafety,but also cause pulmonary stress responses,and 200 nm is less biosafety,causing metabolic disturbances in the lung,liver,and kidney.(2)Based on the above results,80 nm MSNs with lower toxicity were selected as research objects,and MSNs were injected into mice by gavage and intravenous injection respectively.Through the determination of the liver function index,HE staining and pro-inflammatory factor m RNA expression.The results showed that oral administration of MSNs had good biosafety,with normal liver function index,no abnormality in liver tissue and slight increase of the pro-inflammatory factor IL-6.Intravenous administration of MSNs had obvious nanotoxicity,with up-regulated the liver function of AST/ALT,the obvious inflammatory invasion of liver tissue and significant increase of pro-inflammatory factors IL-6,IL-1β and TNF-a.Through the analysis of metabolomics,proteomics and transcriptomics data,the results showed that oral administration of MSNs induced oxidative stress and metabolic disorder of antioxidant pathway in liver.Intravenous administration of MSNs induced liver mitochondrial dysfunction,oxidative phosphorylation inhibition,energy metabolism rearrangement,succinic acid accumulation to promote the release of pro-inflammatory factors,activated of antioxidant pathways,nucleotide upregulation to cell proliferation to protect liver tissue.This study provides a methodological reference for the biosafety evaluation and toxicological research system of nanomaterials.(3)At the cellular level,MSNs of 80 nm and 600 nm were administered to A549 cells,respectively.Through the determination of the changes of cell microstructure,intracellular distribution of MSNs,the m RNA expression of ROS,Ca2+,pro-inflammatory factor and hypoxia-inducer,and cellular metabolism levels.The results showed that80 nm MSNs resulted in decreased cell survival rate,increased ROS and intracellular Ca2+,significantly changed cell mitochondrial ultrastructure of rounded shape,ruptured and disappeared internal cristae,induced intracellular mitochondrial ROS production,promoted inflammation,and intracellular metabolism analysis showed that energy metabolism decreased,nucleic acid synthesis decreased to inhibited cell proliferation.The 600 nm MSNs resulted in significantly reduced cell survival rate,increased ROS and intracellular Ca2+,up-regulated the expressions of pro-inflammatory factors IL-6,IL-1β,TNFa and hypoxia-inducible factor.The ultrastructure of mitochondria did not change significantly,the nucleus was squeezed and deformed,and the endoplasmic reticulum was reduced,inducing intracellular endoplasmic reticulum stress to produce ROS to release Ca2+,promote inflammation,and intracellular metabolism analysis showed enhanced nucleotide synthesis to promote cell proliferation.This work provided us to gain insight into the role of particles in cells,providing a clear physical picture for understanding the toxicity mechanisms of MSNs.