Effects Of Different Surface Modified Iron Oxide Nanoparticles On Gastrointestinal Function

With the widespread use of nanoparticles(NPs)in food and medicine,human exposure to these ingested nanoparticles is inevitable.Oral ingestion of nanoparticles is the main channel for nanoparticles to enter the human gastrointestinal tract(GIT).Nevertheless,there are still some gaps in knowledge of the interaction between NPs and digestive enzymes occurring in the gastrointestinal tract and the physical and chemical transformation in the intestinal tract.The formation of protein corona can significantly affect the properties of nanoparticles and the structure and function of proteins.Therefore,comprehensively understanding the corona formation in the GIT can provide a new perspective for the fate of nanoparticles in the intestine,which is of great significance for the design of nanomedicines in the future.In order to further explore the interactions between nanoparticles and gastrointestinal proteins and the effect of protein corona on gastrointestinal function,nanoparticles with iron oxide as the core and different surface modifications were choosed in this study.Firstly,Fe2O3-NPs with different surface modifications were gavaged at the animal level to adsorb different types of proteins,and the adsorbed proteins are mainly inflammation-related proteins(such as TPSB2,CPA3 and Cmal),and the results showed that the adsorption of γ-Fe2O3 on TPSB2 and CPA3 proteins was significantly higher than that of other surface modified Fe2O3 NPs.Secondly,in order to verify the mechanism of Fe2O3-NPs entering intestinal epithelial cells and evaluate the biokinetics and cytotoxicity in vitro,we established a three-cell model for verification.In addition,in order to more clearly display the physical and chemical transformation of Fe2O3 NPs in the gastrointestinal tract,we established a three-stage gastrointestinal simulator,and found the formation of gastrointestinal protein corona in vitro,and there was no change in iron valence before and after digestion.Finally,we analyzed the secondary structure of the protein adsorbed on the surface of Fe2O3 NPs,and the results showed that the secondary structure of the protein was changed.We systematically explained the fate of Fe2O3 NPs after it entered the gastrointestinal tract from a new perspective,providing a new research direction for the oral delivery of Fe2O3 NPs.