O. Matyshevska

Anti‐oxidant Properties of C60 Fullerenes in vitro

C60 fullerenes at concentration 10−5 M show a protective effect on apoptotic H2O2–treated thymocytes, restoring the level of GSH in cytoplasm and increasing the activity of electron‐transport chain in mitochondria. The protective of C60 fullerenes most probably results from it ability to incorporate into cell membrane and to prevent lipid peroxidation.

DNA nanotechnology of carbon nanotube cells: physico-chemical models of self-organization and properties

Abstract We report UV and IR spectroscopic studies of partially unwrapped double helix DNA molecules with carbon nanotubes of “bundles”-type mixtures, which are spontaneously self-assembled into a coupled blocks of DNA molecule that has the chaotic ball structure with carbon nanotube. The shift of the absorption peak from 279.3 to 285.4 nm for the DNA/nanotube layer in comparison with that for DNA layer may be caused by the hydrogen bonds changing under DNA and nanotube interaction. This fact is confirmed by decrease of the wave number of N–H…N, N–H…O groups on 12 cm−1, the absence of C–CH3 group vibration mode at 1440 cm−1 in IR transmittance spectra from DNA/nanotubes layer, indicative of their self-assembled formation. The results of cell investigations: the maximal photoresponse in the ranges of 515–600 and 950–1070 nm is observed at the light excitation of 500–1100 nm, and change of the applied voltage. The models of electronic and photoelectronic processes in heterostructures are developed and experimentally confirmed.

Biological Effects of C60 Fullerenes in vitro and in a Model System

With the use of artificial lipid membranes, it is shown that C60 fullerenes are capable to penetrate into a lipid bilayer, by locally strengthening its conductivity. C60 fullerenes under the UV/VIS and X-ray irradiation do not influence the MTT reduction and the DNA structure in thymocytes. UV/VIS irradiated C60 fullerenes give rise to the DNA fragmentation and a decrease of the viability of ascitic Erlich carcinoma cells.

Biophysical studies of fullerene-based composite for bio-nanotechnology

Abstract The UV absorption and fluorescence spectra of biological samples and the DNA structural state in cells under X-ray irradiation in the presence of the fullerene-containing composite, synthesized on the basis of aminopropylaerosil, were investigated and analysed in detail. The significant pro-oxidant effect of the fullerene-containing composite at the low concentration of fullerene C60 (10−5 M) was revealed.

Self-organizing DNA/carbon nanotube molecular films

Abstract We have studied the effects of the electronic structure self-formation and charge transfer for the planar system of layers from DNA unwrapped double helix, DNA double helix, DNA unwrapped double helix with carbon nanotubes (CNT) in the separated sections with common bounds on the silicon substrate—DNA chip on Si. The electronic structure of (DNA/CNT) layer are formed as a result of changes of electron levels in adenine, cytozine, guanine and thymine which were directly revealed by UV, IR spectroscopy. The transport properties of such systems are determined by the charge transfer through the barriers in the DNA double helix/unwrapped double helix and in the DNA unwrapped double helix/CNT heterostructures that were proved by tunneling spectroscopy investigations.

Fullerenes immobilized at silica surface: topology, structure and bioactivity

Abstract Supramolecular composites of fullerenes C 60 anchored at bare and modified with spacers silica surface have been synthesized. The properties and structure of composites with different specific concentration and spacer length have been established. The peculiarities of chemosorbed molecules concentration dependence from their size, specific surface area and spacer length have been determined within the framework of a simple geometrical model. Obtained analytical correlation permits to forecast a nonlinearity in the dependence between adsorbed molecule concentration and specific surface area which can exceed 23% at 1.7 times surface area changing, and also allows to estimate effective ligand size from experimental data for similar molecules at adsorbent surfaces of different surface area. Prooxidant effect of synthesized fullerene-containing (10 −6 mole/l by C 60 ) supramolecular composites on the lipid peroxidation processes in liver homogenate has been revealed.

Therapeutic reactive oxygen generation

An increase of the intracellular reactive oxygen species (ROS) concentration leads to the development of oxidative stress and, thus, to the damage of cell components. The cause-and-effect relations between these processes have not been fully established yet. The ability of photo excited supramolecular composites containing fullerenes C60 immobilized at nanosilica particles to generate reactive oxygen species (ROS) in cells of two types (rat thymocytes, and transformed cells of ascite Erlich carcinoma, EAC, and leucosis L1210) is demonstrated. The damaging effect of photo excited C60-composites are shown, which appeared to be selective and manifested in transformed cells, but not in thymocytes. It has been shown that after the irradiation of aqueous solutions or cell suspensions in the presence of fullerene C60, the generation of reactive oxygen species is observed. It has been shown that the influence of photo excited fullerene C60 on metabolic processes depends on the composition of C60-containing complex and on the type of the cells. The damaging effects of photo excited fullerene C60-containing composites were demonstrated to be selective. The data presented suggest that the application of fullerene C60-containing composites for the selective activation of ROS-dependent death program in certain types of tumor cells is very promising.

Electronic Properties of DNA/CNT Chip on Si

Abstract The effects of the electronic structure self-formation and charge transfer for the planar system of layers from DNA unwrapped double helix, DNA double helix, DNA unwrapped double helix with carbon nanotubes (CNT) in the separated sections with common bounds on the silicon substrate - DNA chip on Si were studied in detail. The electronic structure of DNA/CNT layer is formed as a result of changes of electron levels in adenine, cytozine, guanine and thymine which were directly revealed by UV-VIS and IR spectroscopy. The transport properties of such system were determined by the charge transfer through the barriers in the DNA double helix/unwrapped double helix and in the DNA unwrapped double helix/CNT heterostructures that were proved by tunneling spectroscopy investigations.

The electronic properties for DNA/CNT chip on Si

We have studied the effects of the electronic structure self-formation and charge transfer for the planar system of layers consisting of DNA unwrapped double helix, DNA double helix, DNA unwrapped double helix with carbon nanotubes (CNT) in the separated sections with common boundaries on the silicon substrate—DNA chip on Si. The electronic structure of (DNA/CNT) layer is formed as a result of changes of electron levels in adenine, cytozine, guanine and thymine which were directly revealed by UV, IR spectroscopy. The transport properties of such a system are determined by the charge transfer through the barriers in the DNA double helix/unwrapped double helix and in the DNA unwrapped double helix/CNT heterostructures that was proved by tunneling spectroscopy investigations.

Effects of Photoexcited Fullerene C60-Composites in Normal and Transformed Cells

The supramolecular composites containing fullerenes C60 immobilized at nanosilica were used for the design of the molecular systems that can be an effective agent in cancer photodynamic therapy (PDT). In particular, it was shown that photoexcited fullerene C60-containing composites decrease viability of transformed cells, intensify the process of lipid peroxidation (LPO) in cell membranes and accumulation of low-molecular weight DNA fragments, and also decrease the activity of electron-transport chain of mitochondria.