Magnetic study on biodistribution and biodegradation of oral magnetic nanostructures in the rat gastrointestinal tract

Abstract

We have undertaken a magnetic study on the oral biodistribution and biodegradation of nude maghemite nanoparticles of 10 nm average size (MNP) and probiotic bacteria, Lactobacillus fermentum, containing thousands of these same nanoparticles (MNP-bacteria). Using AC magnetic susceptibility measurements of the stomach, small intestine, cecum and large intestine obtained after rat sacrifice, and iron content determination by ICP-OES, we have monitored the biodistribution and biodegradation of the maghemite nanoparticles along the gastrointestinal tract, after oral administration of both MNP and MNP-bacteria. The results revealed that the amount of magnetic nanoparticles accumulated in intestines is sensibly higher when MNP-bacteria were administered, in comparison with MNP. This confirms our initial hypothesis that the use of probiotic bacteria is a suitable strategy to assist the magnetic nanoparticles to overcome the stomach medium, and to achieve their accumulation in intestines. This finding opens doors to different applications. Since iron absorption in humans takes place precisely in the intestines, the use of MNP-bacteria as an iron supplement is a definite possibility. We have actually illustrated how the administration of MNP-bacteria to iron-deficient rats corrects the iron levels after two weeks of treatment.

Unravelling the mechanisms that determine the uptake and metabolism of magnetic single and multicore nanoparticles in aXenopus laevismodel

“…We can consider Xenopus as the bridge between cellbased assays and mammalian models taking into account that the activation of the iron metabolic pathway, especially with SC-DMSA, correlates with previous results in different murine models tracking IONPs biodegradation. 18,32,47 The significant increase of transcript levels of ferritin or dmt1 correlates with previous observations in a Wistar rat animal model where these proteins were quantified by ELISA in tissue samples from the liver, spleen and kidneys, 24 hours after SC-DMSA intravenous injection.…”

“…The application of AC magnetic susceptibility measurements has proven to be an excellent tool to study magnetic nanoparticles in complex matrices, since the diamagnetic signal coming from tissues does not interfere with the superparamagnetic signal of the NPs. 29 This way it was possible to follow the signal of the magnetic nanoparticles in animal models [30][31][32] and to quantify the iron content. This is one of the greatest challenges in the nanomaterials area nowadays, i.e.…”

Effect of Surface Chemistry and Associated Protein Corona on the Long-Term Biodegradation of Iron Oxide Nanoparticles In Vivo

“…Although there are other parameters that may influence the location in temperature of the χ″(T) maximum, in this case, the main factor associated to this transformation is the reduction of the particle size due to the degradation process. 32,33 TEM observations showed that NPs@PMAO incubated in the lysosomal medium were degraded, in contrast to their PC-counterparts or the samples in water, that remained unalterable ( Fig. 3a).…”

Protein-directed synthesis of Bi2S3 nanoparticles as an efficient contrast agent for visualizing the gastrointestinal tract

“…This biodistribution pattern could inspire us to develop their applications further in GI nanomedicine. 44 Liver injury markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were also evaluated to investigate the risks of BSA@Bi 2 S 3 NPs. Although there was a slight disorder in AST at 14 day, all values of ALT and ALP were rather comparable with those of the control group.…”