Yttrium-Iron Garnet Film Magnetometer for Registration of Magnetic Nano- and Submicron Particles: In Vitro and In Vivo Studies.

In the current article, we present a new kind of magnetometer for quantitative detection of magnetic objects (magnetic nano- and submicron particles) in biological fluids and tissues. The sensor is based on yttrium-iron garnet film with optical signal registration system. Inheriting the working principle of a fluxgate magnetometers, the sensor works at a room-temperature, its wide dynamic range allows the measurements in an unshielded environment. A small size of sensitive element combined with a short recovery time after the excitation coils are off provide us with a potentially high spatial and temporal resolution of measurements. We show the feasibility of the developed devices by sensing the remanent magnetization of magnetic nanoparticles (MNPs) both in vitro (test tubes, dry MNPs) and in vivo (local injection of the MNPs into mice).

YIG-Based Sensor System for Millisecond Time Range Magnetorelaxometry.

In the current study we propose a magneto-optical system for registration and analysis of magnetic nano- and microparticles magnetic relaxation. The core of our system is the novel compact magnetometer based on an yttrium-iron garnet film and working at room temperature. The sensor demonstrates sensitivity of 35 pT/√{Hz} at 79 Hz and recovery time less than 100 µs, which allows to register quite fast magnetic relaxations of a low amplitude. All these facts make the system feasible for usage in biological magnetorelaxometry and theranostics. Statistical processing of the relaxation curves allowed us to estimate both amplitudes and relaxation times for various biocompatible magnetic particles at the amount of 100 µg in the test tubes experiments. The system has a great potential of further development for usage in the areas of targeted drug delivery, hyperthermia, magnetic imaging. Being comparatively cheap, the system potentially is of a great interest in the fields of biomedicine and nanomedicine.

COMPARISON OF INFLUENZA A VIRUS INHIBITION IN VITRO BY SIRNA COMPLEXES WITH CHITOSAN DERIVATIVES, POLYETHYLENEIMINE AND HYBRID POLYARGININE-INORGANIC MICROCAPSULES.

Anti-influenza drugs and vaccines have a limited effect due to the high mutation rate of virus genome. The direct impact on the conservative virus genome regions should significantly improve therapeutic effectiveness. The RNA interference mechanism (RNAi) is one of the modern approaches used to solve this problem. In this work, we have investigated the antiviral activity of small interfering RNA (siRNA) against the influenza A/PR/8/34 (H1N1), targeting conserved regions of NP and PA. Polycations were used for intracellular siRNA delivery: chitosan's derivatives (methylglycol and quaternized chitosan), polyethyleneimine, lipofectamine, and hybrid organic/non-organic microcapsules. A comparative study of these delivery systems with fluorescent labeled siRNA was conducted. The antiviral activity of three small interfering RNAs targeting the NP (NP-717, NP-1496) and PA (PA-1630) influenza A viruses genes was demonstrated, depending on the chosen carrier. The most effective intracellular delivery and antiviral activity were observed for hybrid microcapsules.

[The characteristics of the chemical composition and structure of urinary stones and their prevalence in the cities of Moscow, Berlin and of the Kirghiz SSR]. / Osobennosti khimicheskogo sostava i struktury mochevykh kamnei i ikh rasprostranennost' v gorodakh Moskve, Berline i Kirgizskoi SSR.

The authors studied the features of urolithiasis in three different geographical regions: Moscow, the Kirghiz SSR, and Berlin from the findings of examination of the composition and structure of uroliths removed by operation or passed spontaneously, (602 concrements from Moscow, 10,000 from Berlin, and 127 from Kirghizia). X-ray diffraction measurement, infrared spectrophotometry, and polarizing microscopy were conducted to analyze the composition and structure of the stones. Complex biochemical examination was carried out in patients from Moscow and Kirghizia. According to the results of the study, the following features of urolithiasis are common in the studied regions: (1) prevalence of oxalate lithiasis on the whole, which points to the principal role of metabolic factors in lithogenesis; (2) approximately similar amounts of apatite carbonate crystals in the uroliths; (3) certain similarity in composition of concrements from Berlin and Kirghizia. The most essential differences are: (1) the frequency of renal oxalate stones is highest in Berlin and lowest in Moscow. The prevalent types of calcium oxalate stones are: whewellite of concentric structure (linked with hyperuricemia) in Kirghizia; whewellite of small randomly orientated crystals (linked with hypercalciuria) and stones with signs of transformation of weddellite to whewellite in Moscow; (2) lesser distribution of phosphate lithiasis in Berlin than in Kirghizia and particularly in Moscow. Prevalence of struvite crystals in stones from Moscow, the formation of which is linked with the vital activity of Proteus and E. coli; (3) higher distribution of urate lithiasis in Moscow and particularly in Kirghizia where significant metabolic risk factors of lithogenesis were revealed.