DEVELOPMENT OF A METHOD FOR DIAGNOSTICCROHN'S DISEASE USING HYBRID NANOPARTICLES Fe3O4-Au

Abstract

Crohn's disease is an autoimmune disease with the gastrointestinal tract inflammation, with the intercellular distance increase in the epithelial layer of the terminal fragment of the small and large intestine [1]. Current diagnostic methods for the Crohn's disease include endoscopy, MRI, blood and stool analyses, etc. [2]. The symptomatology of the Crohn's disease is similar to that of ulcerative colitis that makes difficulty to provide a correct diagnosis and effective treatment. In the proposed method, wild-type mice of a group of healthy mice and a group of mice with intestinal inflammation, simulating the symptoms of Crohn's disease caused by using the DexstranSodium Sulfat Sigma Aldrich solution, were used. The separation in groups was done in order to compare an amount of nanoparticles excreted with feces in healthy and sick mice.Nanoparticles of different sizes were taken in order to estimate the size of gaps in the intercellular distance in the intestinal wall.The method goal is to determine a time and quantity of nanoparticles excreted from feces. Both type of mice receivedFe3O4-Au nanoparticle solution by the gavage with theconcentration of 200 µg/ml. Three types of nanoparticles were used depending on the Fe3O4 diameter d= 5 nm, 15 nm, 25 nm.The optical properties of samples were studied with the transmission coefficient spectrometry method in visible and near-infrared light.
The detectable spectral region was equal to 430 nm – 1100 nm and was limited with the halogen lamp’s spectrum and detector’s responsivity. The peak of absorbance for magnetite nanoparticles was observed near 460 nm (1) and for gold nanoparticles near 580 nm. This leads to the conclusion that gold nanoparticles broaden the peak of absorbance. transmission spectra were obtained from nanoparticles composite water suspensions with 3 concentrations: 0.1, 0.5, and 1 mg/ml. It can be clearly seen that the second measurement (red line) is accompanied by the intensity decreasing due to nanoparticles agglomeration and precipitation.
Magnetic properties of the samples were investigated using vibration magnetometry. Feces samples from mice which have not received a dose of nanoparticles show typical for biologicaltissues diamagnetic behavior. Magnetic moment of a feces sample mass unit was determined. For the group of healthy mice, the highest magnetic moment per unit mass, and probably the volumetric concentration, of nanoparticles with diameter d= 5 nm in the feces is observed at 8 hours after their administration, while of nanoparticles with diameter d= 15 nm - after 24 hours. For the samples with d= 25 nm the highest moment per unit mass is observed after 24 hours. Thenanoparticles were also found in the feces of sick mice. On average, magnetic moment per unit mass is 2-5 times higher in healthy mice than in sick ones that may indicate a penetration of nanoparticles into the intercellular space of the intestine wall. It was concluded that the proposed experimental method of diagnosing Crohn's disease by means of the hybrid Fe3O4-Au nanoparticles could be further applied.

Speaker

Grigoreva Zoja
Immanuel Kant Baltic Federal University
Russia

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