Antitumor effects and hematotoxicity of C60-Cis-Pt nanocomplex in mice with Lewis lung carcinoma.

BACKGROUND: Cisplatin (Cis-Pt) is a widely used anticancer drug but its therapeutic efficiency is limited by hemato-, cardio-, hepato-, nephro- and neurotoxicity. Complexation of Cis-Pt with C60 fullerene nanoparticle will allow to enhance the antitumor activity of the drug and to reduce its side toxic effects. AIM: To estimate the antitumor effects of С60-Cis-Pt nanocomplex in Lewis lung carcinoma (LLC) and analyze hematological toxicity in tumor-bearing mice. MATERIALS AND METHODS: Complexation of C60 fullerene and Cis-Pt molecule was studied by computer simulation. С60-Cis-Pt nanocomplex was i.p. injected to LLC-bearing mice in a total dose of 7.5 mg/kg (C60:Cis-Pt as 3.75:3.75 mg/kg). The survival of tumor-bearing mice and the relative reduction of tumor weight was recorded. Blood indices were determined using the Particle Counter PCE-210 automatic hematology analyzer. RESULTS: Computer simulation demonstrated the formation of С60-Cis-Pt nanocomplex in physiological medium and its stability due to the hydrophobic interactions. Treatment with C60-Cis-Pt nanocomplex increased survival time of LLC-bearing mice by 32%, normalized hemoglobin content (up to 100 g/l), erythrocyte and platelet count as compared to the untreated LLC-bearing mice. Tumor weight decreased by 35.5%; the mitotic index of tumor cells decreased by 78%, and apoptotic index increased by 75%. The revealed effects of the C60-Cis-Pt nanocomplex were more pronounced than the effects of Cis-Pt or C60 fullerene alone in equivalent dose. CONCLUSION: Treatment with C60-Cis-Pt nanocomplex prolonged the survival of LLC-bearing mice and reduced anemia in LLC-bearing mice.

C60 Fullerene as Promising Therapeutic Agent for the Prevention and Correction of Skeletal Muscle Functioning at Ischemic Injury.

The therapeutic effect of pristine C60 fullerene aqueous colloid solution (C60FAS) on the functioning of the rat soleus muscle at ischemic injury depending on the time of the general pathogenesis of muscular system and method of administration C60FAS in vivo was investigated. It was found that intravenous administration of C60FAS is the optimal for correction of speed macroparameters of contraction for ischemic muscle damage. At the same time, intramuscular administration of C60FAS shows pronounced protective effect in movements associated with the generation of maximum force responses or prolonged contractions, which increase the muscle fatigue level. Analysis of content concentration of creatine phosphokinase and lactate dehydrogenase enzymes in the blood of experimental animals indicates directly that C60FAS may be a promising therapeutic agent for the prevention and correction of ischemic-damaged skeletal muscle function.

Comparative Analysis of the Antineoplastic Activity of C60 Fullerene with 5-Fluorouracil and Pyrrole Derivative In Vivo.

The antitumor activity of pristine C60 fullerene aqueous solution (C60FAS) compared to 5-fluorouracil (5-FU) and pyrrole derivative 1-(4-Cl-benzyl)-3-Cl-4-(CF3-fenylamino)-1H-pyrrol-2.5-dione (MI-1) cytostatic drugs was investigated and analyzed in detail using the model of colorectal cancer induced by 1.2-dimethylhydrazine (DMH) in rats. The number, size, and location of the tumors were measured, and the pathology was examined. It was found that the number of tumors and total lesion area decreased significantly under the action of C60FAS and MI-1. Because these drugs have different mechanisms of action, their simultaneous administration can potentially increase the effectiveness and significantly reduce the side effects of antitumor therapy.

Interaction of C60 fullerene complexed to doxorubicin with model bilipid membranes and its uptake by HeLa cells.

With an aim to elucidate the effects of C60 fullerene complexed with antibiotic doxorubicin (Dox) on model bilipid membranes (BLM), the investigation of the electrical properties of BLM under the action of Dox and C60 fullerene, and of their complex, C60+Dox,was performed. The complex as well as its components exert a clearly detectable influence on BLM, which is concentration-dependent and also depends on phospholipid composition. The mechanism of this effect originates either from intermolecular interaction of the drug with fatty-acid residues of phospholipids, or from membranotropic effects of the drug-induced lipid peroxidation, or from the sum of these two effects. By fluorescence microscopy the entering of C60 + Dox complex into HeLa cells was directly shown.

Impact of C 60 fullerene on the dynamics of force-speed changes in soleus muscle of rat at ischemia-reperfusion injury.

The effect of C60 fullerene nanoparticles (30-90 nm) on dynamics of force response development to stimulated soleus muscle of rat with ischemic pathology, existing in muscle during the first 5 hours and first 5 days after 2 hours of ischemia and further reperfusion, was investigated using the tensometric method. It was found that intravenous and intramuscular administration of C60 fullerene with a single dose of 1 mg/kg exert different therapeutic effects dependent on the investigated macroparameters of muscle contraction. The intravenous drug administration was shown to be the most optimal for correction of the velocity macroparameters of contraction due to muscle tissue ischemic damage. In contrast, the intramuscular administration displays protective action with respect to motions associated with generation of maximal force response or continuous contractions elevating the level of muscle fatigue. Hence, C60 fullerene, being a strong antioxidant, may be considered as a promising agent for effective therapy of pathological states of the muscle system caused by pathological action of free radical processes.

Application of C60 Fullerene-Doxorubicin Complex for Tumor Cell Treatment In Vitro and In Vivo.

Development of nanocarriers for effective drug delivery to molecular targets in tumor cells is a real problem in modern pharmaceutical chemistry. In the present work we used pristine C60 fullerene as a platform for delivery of anticancer drug doxorubicin (Dox) to its biological targets. The formation of a complex of C60 fullerene with Dox (C60 + Dox) is described and physico-chemical characteristics of such complex are presented. It was found that Dox conjugation with C60 fullerene leads to 1.5-2-fold increase in Dox toxicity towards various human tumor cell lines, compared with such effect when the drug is used alone. Cytotoxic activity of C60 + Dox complex is accompanied by an increased level of cell produced hydrogen peroxide at early time point (3 h) after its addition to cultured cells. At the same time, cellular production of superoxide radicals does not change in comparison with the effect of Dox alone. Cytomorphological studies have demonstrated that C60 + Dox complexes kill tumor cells by apoptosis induction. The results of in vivo experiments using Lewis lung carcinoma in mice confirmed the enhancement of the Dox toxicity towards tumor cells after drug complexation with C60 fullerene. The effect of such complex towards tumor-bearing mice was even more pronounced than that in the in vitro experiment with targeting human tumor cells. The tumor volume decreased by 2.5 times compared with the control, and an average life span of treated animals increased by 63% compared with control. The obtained results suggest a great perspective of application of C60 + Dox complexes for chemotherapy of malignant tumors.

C60 fullerene prevents genotoxic effects of doxorubicin in human lymphocytes in vitro.

The self-ordering of C60 fullerene, doxorubicin and their mixture precipitated from aqueous solutions was investigated using atomic-force microscopy. The results suggest the complexation between the two compounds. The genotoxicity of doxorubicin in complex with C60 fullerene (C 60+Dox) was evaluated in vitro with comet assay using human lymphocytes. The obtained results show that the C60 fullerene prevents the toxic effect of Dox in normal cells and, thus, C60+Dox complex might be proposed for biomedical application.

Effect of fullerene C60 on ATPase activity and superprecipitation of skeletal muscle actomyosin.

Creation of new biocompatible nanomaterials, which can exhibit the specific biological effects, is an important complex problem that requires the use of last accomplishments of biotechnology. The effect of pristine water-soluble fullerene C60 on ATPase activity and superprecipitation reaction of rabbit skeletal muscle natural actomyosin has been revealed, namely an increase of actomyosin superprecipitation and Mg2+, Ca(2+)- and K(+)-ATPase activity by fullerene was investigated. We conclude that this finding offers a real possibility for the regulation of contraction-relaxation of skeletal muscle with fullerene C60.

Effect of iron-doped multi-walled carbon nanotubes on lipid model and cellular plasma membranes.

The aim of the present work was the study of the interaction of multi-walled carbon nanotubes filled with iron (Fe-MWCNTs) with bimolecular lipid model membrane (BLM) and cellular plasma membrane (PM). The findings demonstrate that the Fe-MWCNTs adsorb on the BLM surface with possible partial build up in the hydrophobic area of fatty acid residues of lipids and increase its specific conductivity and capacity. Furthermore, upon interaction with the PM, the Fe-MWCNTs form channels which allow the flow of water to the cells and the externalization of phosphatidylserine from the inner to the outer PM leaflet.

Pristine C(60) fullerenes inhibit the rate of tumor growth and metastasis.

AIM: To estimate the impact of C(60) fullerene aqueous solution (C(60)FAS) on the rate of transplanted malignant tumor growth and metastasis. METHODS: Lewis lung carcinoma was transplanted into С57Bl/6J male mice. Conventional methods for the evaluation of antitumor and antimetastatic effects have been used. RESULTS: The C(60)FAS at low single therapeutic dose of 5 mg/kg inhibited the growth of transplanted malignant tumor (antitumor effect) and metastasis (antimetastatic effect): the maximum therapeutic effect was found to be of 76.5% for the tumor growth inhibition; the increase of animal life span by 22% was found; the metastasis inhibition index was estimated as 48%. CONCLUSION: It was found that water-soluble pristine С(60) fullerenes efficiently inhibit the transplanted malignant tumor growth and metastasis.

Low-temperature 1H-NMR spectroscopic study of doxorubicin influence on the hydrated properties of nanosilica modified by DNA.

The effect of the anticancer drug--doxorubicin (Dox) on hydration properties of a nanocomposite material deposited on silica and modified by small amount of DNA (0.6 wt%) was studied by means of (1)H NMR spectroscopy at low temperatures (in the range of 200-280 K). Signals of either weakly (WAW) or strongly (SAW) associated water, as well as water associated with electrondonor groups of the composite surface (ASW), were observed. The findings reveal that, depending on the temperature and the composition of the dispersion medium, fast molecular exchange takes place between different forms of interphase water. The presence of Dox (0.1-0.2 wt%) in the dispersion medium leads to change of the relative concentrations of different forms of water.

Hyperthermic effect of multi-walled carbon nanotubes stimulated with near infrared irradiation for anticancer therapy: in vitro studies.

UNLABELLED: It is proposed to use the novel paradigm of treating cancer with hyperthermic therapy using multi-walled carbon nanotubes (MWCNT) stimulated with near infrared (NIR) irradiation. AIM: To establish the capacity of MWCNT stimulated with NIR irradiation to destroy Erlich ascitic carcinoma (EAC) cells. MATERIALS AND METHODS: EAC cells suspension was irradiated with NIR heating lamp with a wavelength of 0.78-1.40 mm and power density of 3.5 W/cm2 over 1.5 min in the presence of MWCNT (0.1 mg/ml). The changes in the temperature of suspension with the NIR exposure time was measured using the differential cooper-constantan thermocouple. The viability of EAC cells was evaluated by trypan blue staining. RESULTS: The death of 95.2% of EAC cells in the presence of MWCNT was observed after 1.5 min of NIR light irradiation: thermal ablation temperature was approximately 50 degrees C. CONCLUSIONS: It was demonstrated that addition of MWCNT to EAC cell suspension results in the photo-ablative destruction of cells exposed to short time NIR irradiation.

Effect of the visible light irradiation of fullerene-containing composites on the ROS generation and the viability of tumor cells.

AIM: To study the effect of fullerene-containing composites, irradiated by visible light, on the radical oxygen species (ROS) generation in thymocytes, ascitic cells from Erlich's tumor and leukemia cells L1210; to investigate viability of these cells in the presence of fullerene-containing composites under irradiation conditions. MATERIALS AND METHODS: The viability of cells was evaluated by staining with 0.4% solution of the trypan blue; ROS were detected with the use of electron paramagnetic resonance (EPR) spectroscopy and spin traps; solutions of fullerene-containing composites were irradiated with mercury-vapor lamp. RESULTS: We demonstrated that under irradiation conditions fullerene-containing composites increase the rate of ROS generation and decrease the number of viable tumor cells. CONCLUSIONS: The obtained data allow to consider the fullerene-containing composites as potential agents for photodynamic therapy.

Magnetic carbon.

The discovery of nanostructured forms of molecular carbon has led to renewed interest in the varied properties of this element. Both graphite and C60 can be electron-doped by alkali metals to become superconducting; transition temperatures of up to 52 K have been attained by field-induced hole-doping of C60 (ref. 2). Recent experiments and theoretical studies have suggested that electronic instabilities in pure graphite may give rise to superconducting and ferromagnetic properties, even at room temperature. Here we report the serendipitous discovery of strong magnetic signals in rhombohedral C60. Our intention was to search for superconductivity in polymerized C60; however, it appears that our high-pressure, high-temperature polymerization process results in a magnetically ordered state. The material exhibits features typical of ferromagnets: saturation magnetization, large hysteresis and attachment to a magnet at room temperature. The temperature dependences of the saturation and remanent magnetization indicate a Curie temperature near 500 K.

Editing does not exist for mammalian selenocysteine tRNAs.

It has been reported that selenocysteine tRNA from bovine liver is completely edited to two isoacceptor species, called tRNA([Ser]SecNCA) and tRNA([Ser]SecCmCa), which differ from the gene sequence. We used direct tRNA sequencing, mobility shift analyses, primer extension, restriction enzyme digestion and single strand conformational polymorphism (SSCP) analyses of products from reverse transcription coupled with polymerase chain reaction (RT/PCR), sequencing of RT/PCR products and HPLC-coupled mass spectrometry to reproduce this result and show here that editing of these tRNAs does not occur.

[The diagnostic value of determining serum-mercaptans in liver disease (author's transl)]. / Untersuchungen über den diagnostischen Wert der Bestimmung von Mercaptanen im Serum bei Lebererkrankungen.

Aliphatic mercaptans (aethanthiol, methanthiol, dimethylsulphide) can be measured in serum with a simple and rapid gaschromatographic method. The test takes 30 minutes. Aethantiol was found to be increased ten-fold (P less than 0.0001) in patients with acute hepatic failure (endogenous coma), while in exogenous hepatic coma it was always normal or decreased. Mild increase in aethanthiol concentration (two or threefold) was also found in chronic aggressive hepatitis, cirrhosis and obstructive jaundice. Methanthiol concentration was elevated in patients with endogenous and exogenous hepatic coma. Values for methanthiol are, however, of only limited use, because methionine is converted in small amounts to methanthiol during the test procedures. Dimethylsulphide is found in only very severe cases of endogenous or exogenous hepatic coma and can be considered to be a prognostically unfavourable sign. Determination of mercaptans makes it possible to differentiate exactly between endogenous and exogenous hepatic coma. Its value also lies in the recognition of the severity of endogenous intoxication and it is suitable for serial and control determination of the effectiveness of therapeutic measures.

Large agarose beads for extracorporeal detoxification systems.

A method is reported by which agarose beads of diameter 1000 to 10000 microns can be prepared from Sepharose (R) 4B (native bead diameter 40 to 190 microns). Haemoperfusion experiments indicate that the enlarged beads are relatively haemocompatible; platelet loss is considerably less than that reported for many other bio-materials employed in haemoperfusion, and haemolysis is slight even after perfusion for several hours at flow-rates in excess of 25 ml/min. The beads can be activated by cyanogen bromide for the immobilisation of proteins. The sites for protein fixation are not restricted to the outside surface of the beads; small water soluble molecules, and serum proteins diffuse quite rapidly through the enlarged beads. A possible medical application of the large beads is in extracorporeal detoxification by chromatographic extraction or enzymatic modification, particularly of lipophilic toxins, using the enlarged beads as a carrier-matrix. The results described in this publication prove the viability of this concept. Such methods should be especially useful as artificial supports in fulminant hepatic failure.