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.

[The use of a urethral catheter with an ultrasound-induced biopolymer drug coating for the prevention of recurrent bladder neck sclerosis in patients after endoscopic treatment of benign prostate hyperplasia].

Recurrent bladder neck sclerosis is one of the common complications of endoscopic treatment of benign prostate hyperplasia, which often leads to multiple re-operations, including complex open and laparoscopic reconstructive procedures. One of the most promising minimally invasive methods for preventing recurrence of bladder neck sclerosis is balloon dilatation under transrectal ultrasound guidance. To improve the results of using this technique, a urethral catheter with a biopolymer coating, capable of depositing a drug and eluting it under the influence of diagnostic ultrasound, was proposed.

Evaluation of Cellular Toxicity and Preclinical Safety of Using an Inhalable Liposomal form of Dexamethasone.

A liposomal form of dexamethasone was obtained. Liposomal vesicles were formed. The efficiency of incorporating dexamethasone into the liposomes was 99.7%. The cytotoxicity of the obtained liposomes was studied on a culture of human lung fibroblast cells using the MTT assay. The toxicity of liposomal dexamethasone was less than that of dexamethasone solution after a 24-h incubation. The half-maximum inhibitory concentration (IC50) was not achieved after 24 h when exposed to liposomal dexamethasone whereas IC50 was 27.5 mg/mL for lecithin (empty liposomes) and 177 µg/mL for dexamethasone solution. The toxicity of liposomal dexamethasone increased much more than that of dexamethasone solution after 48 h of incubation with IC50 values of 36 and 156 µg/mL, respectively. Thus, the liposomal form of dexamethasone has a latent period for implementation of the cytostatic (antiproliferative) action. Experiments on laboratory white rats of both sexes revealed that the inhalation use of liposomal dexamethasone insignificantly changed the functional parameters of their respiratory and cardiovascular systems. The study results could be used for conducting clinical trials.

Design of Nanosomal Form of Aprotinin.

Liposomes containing aprotinin were produced by the phase inversion technique and purified by gel filtration. Aprotinin inclusion was assessed fluorescence labeling of the protein. The size of obtained liposomes was 212±35 nm and aprotinin concentration in the liposomal suspension was 3000 KIU/ml. The efficiency of aprotinin inclusion into liposomes was 31.9%.