Генерування активних форм кисню фотозбудженими вуглецевими нанотрубками та їхня гіпертермічна дія в системі in vitro

С использованием дифференциальной медь-константановой термопары обнаружено зависимое от времени нагревание как водной суспензии МУНТ до температуры ~70 °С при их облучении ближним ИК-светом в течение 2 мин, так и суспензии клеток АКЕ и L1210 в присутствии МУНТ - до 50 и 47 °С соответственно в течение 1,5 мин их облучения ближним ИК-светом. В этих условиях наблюдали снижение количества жизнеспособных клеток АКЕ на 95,2±4,8% и клеток L1210 - на 94,8±5,2% относительно контроля.

Ключевые слова: тимоциты, клетки лейкоза L1210, клетки асцитной карциномы Эрлиха, углеродные нанотрубки, бимолекулярная липидная мембрана, ИК-облучение, активные формы кислорода, гипертермия.

Annotation

Remeniak O.V. Generation of reactive oxygen species by photoexcited carbon nanotubes and their hyperthermic effect in vitro. - Manuscript.

Dissertation for the PhD degree in speciality 03.00.02 - Biophysics. - Kyiv National Taras Shevchenko University, Kyiv, 2010.

The purpose of the dissertation was to study the structural organization of carbon nanotubes (CNT) in water suspension, their interaction with artificial bimolecular lipid membranes (BLM), the toxic action of CNT in suspensions of normal and transformed cells, their ability to generate the reactive oxygen species (ROS) under the near infrared (NIR) irradiation and to cause the hyperthermic effect in vitro.

The type of CNT (single- (SWCNT) and multi-walled (MWCNT)), their diameter, which was estimated to be in a range of 1,4-2 nm for SWCNT and 8-12 nm for MWCNT, their length, which was less than 1 µm, were determined using the transmission and scanning electron microscopy. With use of VIS/IR and Raman spectroscopy it was established that the aggregation state of CNT depends on their concentration in water. Non-stationary current-voltage characteristics method revealed that CNT (0,05 and 0,5 mg/ml) locally increase the conductivity of BLM as a result of the CNT adsorption on the lipid bilayer surface and their ability to initiate the additional channels in the membrane. The BLM conductivity in the presence of MWCNT exceeds one in the presence of SWCNT. SWCNT at the concentration >0,5 mg/ml and MWCNT at the concentration >0,1 mg/ml are showed to have the hemolytic and cytotoxic effects, namely accelerate the hemolysis and increase the portion of hemolytic erythrocytes of rat, decrease the number of viable thymocytes, leucosis L1210 and Erlich ascitic carcinoma (EAC) cells. With the use of methods of electron paramagnetic resonance (EPR) spectroscopy and spin traps it was established that the MWCNT irradiated by NIR-light 780-1400 nm for 30 s generate ROS with the rate of ~10 nMol/(mg?min) independently on their concentration in water. However, in dependence on MWCNT concentration in water they demonstrate the time dependent ROS generation with the indicated rate after photoirradiation action. It was found that the rate of ROS generation in the suspensions of EAC and L1210 cells in the presence of MWCNT (0,1 mg/ml) after 30 s NIR exposure is increased to 4,5 and 5,3 times respectively relative control. By use the differential cooper-constantan thermocouple it was found the considerable heating both in the aqueous suspension of MWCNT and EAC and L1210 cell suspensions in the presence of MWCNT during their exposure to NIR-light, which led to a significant reduction in the number of viable cells (~95%).

Key words: thymocytes, leucosis L1210 cells, Erlich ascites carcinoma cells, carbon nanotubes, bimolecular lipid membranes, NIR-irradiation, reactive oxygen species, hyperthermia.

Размещено на Allbest.ru