3-Aminopropylsilane-modified iron oxide nanoparticles for contrast-enhanced magnetic resonance imaging of liver lesions induced by Opisthorchis felineus

Alexander M Demin,1,* Alexandra G Pershina,2,3,* Vladimir V Ivanov,2 Kseniya V Nevskaya,2 Oleg B Shevelev,4 Artyom S Minin,5 Iliya V Byzov,5 Alexey E Sazonov,2 Victor P Krasnov,1 Ludmila M Ogorodova2 1Postovsky Institute of Organic Synthesis of RAS (Ural Branch), Yekaterinburg, 2Siberian State Medical University, 3Russian National Research Tomsk Polytechnic University, Tomsk, 4Institute of Cytology and Genetics SB RAS, Novosibirsk, 5Miheev Institute of Metal Physics of RAS (Ural Branch), Yekaterinburg, Russia *These authors contributed equally to this work Purpose: Liver fluke causes severe liver damage in an infected human. However, the infection often remains neglected due to the lack of pathognomonic signs. Nanoparticle-enhanced magnetic resonance imaging (MRI) offers a promising technique for detecting liver lesions induced by parasites.Materials and methods: Surface modification of iron oxide nanoparticles produced by coprecipitation from a solution of Fe3+ and Fe2+ salts using 3-aminopropylsilane (APS) was carried out. The APS-modified nanoparticles were characterized by transmission electron microscopy, fourier transform infrared spectroscopy, and thermogravimetric analysis . Magnetic resonance properties of MNPs were investigated in vitro and in vivo.Results: The amount of APS grafted on the surface of nanoparticles (0.60±0.06 mmol g-1) was calculated based on elemental analysis and infrared spectroscopy data. According to transmission electron microscopy data, there were no essential changes in the structure of nanoparticles during the modification. The APS-modified nanoparticles exhibit high magnetic properties; the calculated relaxivity r2 was 271 mmol-1 s-1. To obtain suspension with optimal hydrodynamic characteristics, amino groups on the surface of nanoparticles were converted into an ionic form with HCl. Cellular uptake of modified nanoparticles by rat hepatoma cells and human monocytes in vitro was 74.1±4.5 and 10.0±3.7 pg [Fe] per cell, respectively. Low cytotoxicity of the nanoparticles was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Annexin V/7-aminoactinomycin D flow cytometry assays. For the first time, magnetic nanoparticles were applied for contrast-enhanced MRI of liver lesions induced by Opisthorchis felineus.Conclusion: The synthesized APS-modified iron oxide nanoparticles showed high efficiency as an MRI contrast agent for the evaluation of opisthorchiasis-related liver damage. Keywords: magnetic nanoparticles, alkoxysilane, magnetic resonance imaging, liver fluk

Opisthorchis felineus negatively associates with skin test reactivity in Russia-EuroPrevall-International Cooperation study

BACKGROUND: Most studies on the relationship between helminth infections and atopic disorders have been conducted in (sub)tropical developing countries where exposure to multiple parasites and lifestyle can confound the relationship. We aimed to study the relationship between infection with the fish-borne helminth Opishorchis felineus and specific IgE, skin prick testing, and atopic symptoms in Western Siberia, with lifestyle and hygiene standards of a developed country. METHODS: Schoolchildren aged 7-11 years were sampled from one urban and two rural regions. Skin prick tests (SPT) and specific IgE (sIgE) against food and aeroallergens were measured, and data on allergic symptoms and on demographic and socioeconomic factors were collected by questionnaire. Diagnosis of opisthorchiasis was based on PCR performed on stool samples. RESULTS: Of the 732 children included, 34.9% had opisthorchiasis. The sensitization to any allergen when estimated by positive SPT was 12.8%, while much higher, 24.0%, when measured by sIgE. Atopic symptoms in the past year (flexural eczema and/or rhinoconjunctivitis) were reported in 12.4% of the children. SPT was positively related to flexural eczema and rhinoconjunctivitis, but not to wheezing. Opisthorchiasis showed association with lower SPT response, as well as borderline association with low IgE reactivity to any allergen. However, the effect of opisthorchiasis on SPT response was not mediated by IgE, suggesting that opisthorchiasis influences SPT response through another mechanism. Opisthorchiasis also showed borderline association with lower atopic symptoms. CONCLUSIONS: There is a negative association between a chronic helminth infection and skin prick test reactivity even in a developed country