Konstantin O. Khokhlov

Разработка неинвазивных методов воздействия на опухолевые клетки является актуальной задачей. Проблема заключается в недостаточном изучении временной динамики клеточных ответов и отсутствии стандартизированных подходов к оптимизации параметров магнитного воздействия. Цель исследования – апробация разработанного портативного лабораторного стенда для генерации импульсного магнитного поля и выявления диапазонов параметров, при которых наблюдается различие в цитотоксическом ответе на опухолевые клетки на примере клеток аденокарциномы шейки матки (HeLa) in vitro. Объекты: фибробласты человека и клетки аденокарциномы шейки матки (HeLa). Воздействие проводили постоянным, однополярным и биполярным импульсными магнитными полями. Жизнеспособность оценивали в камере Горяева на 1, 3 и 7-е сутки. Морфологию – при окрашивании по Романовскому – Гимзе. Статистическая обработка – U-критерий Манна – Уитни, n = 3. Характер клеточного ответа определяется типом поля, длительностью экспозиции и временем наблюдения. Биполярное импульсное поле (5 мин) вызывало гибель HeLa (жизнеспособность 1 %) при сохранении фибробластов (89 %) на 7-е сутки. Продемонстрирована работоспособность портативного стенда. Получены предварительные данные о параметрах (биполярное поле, 5 мин, 35 мТл, ≤10 Гц), при которых наблюдается различие в жизнеспособности клеток HeLa и фибробластов in vitro, что создает основу для дальнейших исследований.

The well-known fluorophore, namely 1,3,6,8-tetrakis[(trimethylsilyl)ethynyl]pyrene, has been studied profoundly as a fluorescent sensor toward nitroaromatic compounds in solutions and vapor phase. Three prototypes of fluorescent materials for vapor sensing were prepared via electrospinning and drop-casting onto the melamine formaldehyde foam with the fluorophore as a pure solid or as a dopant in the polystyrene matrix. It has been shown that this fluorophore and solid fluorescent materials based on it have high detection limits toward nitroaromatic compounds within the range of 10⁻⁸ to 10⁻⁹ M in acetonitrile solution and within the up to ppb range in the vapor phase. The model, expanding on Frisch’s permeation model, was utilized to characterize the fluorescence response of materials relative to vapor concentration and duration of exposure to vapor. All prototypes can be used as sensor materials exhibiting a good sensitivity and selectivity for the original hand-made sniffer for detecting nitro-containing explosives in the vapor phase for real-time application.

Five random copolymers comprising styrene and styrene with pendant fluorophore moieties, namely pyrene, naphthalene, phenanthrene, and triphenylamine, in molar ratios of 10:1, were synthesized and employed as fluorescent sensors. Their photophysical properties were investigated using absorption and emission spectral analyses in dichloromethane solution and in solid state. All copolymers possessed relative quantum yields up to 0.3 in solution and absolute quantum yields up to 0.93 in solid state, depending on their fluorophore components. Fluorescence studies showed that the emission of these copolymers is highly sensitive towards various nitroaromatic compounds, both in solution and in the vapor phase. The detection limits of these fluorophores for nitroaromatic compounds in dichloromethane solution proved to be in the range of 10⁻⁶ to 10⁻⁷ mol/L. The sensor materials for new hand-made sniffers based on these fluorophores were prepared by electrospinning and applied for the reliable detection of nitrobenzene vapors at 1 ppm in less than 5 min.

Present concern about the terrorist attacks in public places initiate the rise of interest towards preventive actions, one of those being actual explosive substances express detection. The device under consideration in current work is capable of detecting the presence of explosive stuff through its vapors luminescence measurement. Also according to a number of federal designations explosive stuff type should be identified. Although previous version of the device could not distinguish the exact explosive substance, our new light detecting path, electronics and processing units introduced in the modified device will enable to discrete the kind of the explosive. Moreover, enhanced computational capabilities presented in this modification are expected to give much more accurate results and reliability. Presently the work is under practical realisation stage and experimental results on our modification will be presented in nearest future.