Nanostructures of hydrated C60 fullerene (C60HyFn) protect rat brain against alcohol impact and attenuate behavioral impairments of alcoholized animals

Potential Role of Carbon Nanomaterials in the Treatment of Malignant Brain Gliomas

Malignant gliomas are the most common primary brain tumors in adults up to an extent of 78% of all primary malignant brain tumors. However, total surgical resection is almost unachievable due to the considerable infiltrative ability of glial cells. The efficacy of current multimodal therapeutic strategies is, furthermore, limited by the lack of specific therapies against malignant cells, and, therefore, the prognosis of these in patients is still very unfavorable. The limitations of conventional therapies, which may result from inefficient delivery of the therapeutic or contrast agent to brain tumors, are major reasons for this unsolved clinical problem. The major problem in brain drug delivery is the presence of the blood-brain barrier, which limits the delivery of many chemotherapeutic agents. Nanoparticles, thanks to their chemical configuration, are able to go through the blood-brain barrier carrying drugs or genes targeted against gliomas. Carbon nanomaterials show distinct properties including electronic properties, a penetrating capability on the cell membrane, high drug-loading and pH-dependent therapeutic unloading capacities, thermal properties, a large surface area, and easy modification with molecules, which render them as suitable candidates for deliver drugs. In this review, we will focus on the potential effectiveness of the use of carbon nanomaterials in the treatment of malignant gliomas and discuss the current progress of in vitro and in vivo researches of carbon nanomaterials-based drug delivery to brain.

Effect of Hydrated Carbon 60 Fullerene on Frozen Ram Semen Quality

The aim of this study was to evaluate the effect of hydrated carbon 60 fullerene (C₆₀HyFn) on ram semen quality during cryopreservation. Three ejaculates from each of seven Akkaraman rams were collected using an artificial vagina during the nonbreeding season and pooled. Pooled semen samples were divided into 10 equal parts and diluted with tris + egg yolk extender not containing (control) and containing 100, 200, 400, and 800 nM and 1, 5, 10, 20, and 40 μM C₆₀HyFn at 37°C. After addition of 5% glycerol and an equilibration process for 3 hours, the samples were frozen in 0.25-mL straws in an automatic freezing device at -140°C and stored in a liquid nitrogen container. Straws were thawed 24 hours after freezing and analyzed immediately with no incubation period. Motility, kinematic parameters, abnormality, vitality, hypo-osmotic swelling test (HOST), and oxidative stress levels were analyzed in thawed semen. Compared with the control, 200, 400, and 800 nM and 1 and 5 μM C₆₀HyFn doses increased motility and HOST values and decreased the dead sperm rate. When compared with the control, addition of C₆₀HyFn significantly decreased malondialdehyde levels (between 200 nM and 40 μM doses) and significantly increased glutathione peroxidase (between 800 nM and 40 μM doses) and catalase (between 1 and 40 μM doses) activities. In conclusion, results of this study show that the C₆₀HyFn nanoparticles are nontoxic to ram semen and their supplementation in the extender is beneficial to sperm motility and membrane integrity after freeze-thawing.

Carbon nanostructures: The drug and the delivery system for brain disorders

Neurodegenerative disorders and brain tumors are major pathological conditions affecting the brain. The delivery of therapeutic agents into the brain is not as easy as to other organs or systems. The presence of the blood-brain barrier (BBB) makes the drug delivery into the brain more complicated and challenging. Many techniques have been developed to overcome the difficulties with BBB and to achieve brain-targeted drug delivery. Incorporation of the drugs into nanocarriers capable to penetrate BBB is a simple technique. Different nanocarriers have been developed including polymeric nanoparticles, carbon nanoparticles, lipid-based nanoparticles, etc. Carbon nanostructures could make a superior position among them, because of their good biocompatibility and easy penetration of BBB. Carbon-family nanomaterials consist of different carbon-based structures including zero-dimensional fullerene, one-dimensional carbon nanotube, two-dimensional graphene, and some other related structures like carbon dots and nanodiamonds. They can be used as efficient carriers for drug delivery into the brain. Apart from the drug delivery applications, they can also be used as a central nervous system (CNS) therapeutic agent; some of the carbon nanostructures have neuroregenerative activity. Their influence on neuronal growth and anti-amyloid action is also interesting. This review focuses on different carbon nanostructures for brain-targeted drug delivery and their CNS activities. As a carrier and CNS therapeutic agent, carbon nanostructures can revolutionize the treatment of brain disorders.

Pristine C60 Fullerene Nanoparticles Ameliorate Hyperglycemia-Induced Disturbances via Modulation of Apoptosis and Autophagy Flux

Diabetes mellitus is a prevalent metabolic disorder associated with multiple complications including neuropathy, memory loss and cognitive decline. Despite a long history of studies on diabetic complications, there are no effective therapeutic strategies for neuroprotection in diabetes. Hyperglycemia-induced imbalance in programmed cell death could initiate a decline in neural tissue cells viability. Various nanomaterials can induce either cell death or cell survival dependent on the type and surface features. Pristine C₆₀ fullerene is a nontoxic nanomaterial, which exhibits antioxidant and cytoprotective properties. However, the precise molecular mechanism with which the C₆₀ nanoparticle exerts cytoprotective effect in diabetic subjects has not yet been fully addressed. Thus, this study aimed to determine whether C₆₀ fullerene prevents oxidative stress impairment and to explore the effects of C₆₀ fullerene on apoptosis and autophagy in diabetes mellitus to clarify its potential mechanisms. These effects have been examined for olive oil extracted C₆₀ fullerene on the hippocampus of STZ diabetic rats. Up-regulation of Caspase-3, Beclin-1 and oxidative stress indexes and down-regulation of Bcl-2 were observed in the brain of STZ-diabetic rats. The exposure to C₆₀ fullerene for a period of 12 weeks ameliorate redox imbalance, hyperglycemia-induced disturbances in apoptosis and autophagy flux via modulation of Caspase-3, Bcl-2, Beclin-1 and LC3I/II contents. Furthermore, C₆₀ fullerene ameliorated the LC3I/II ratio and prevented extremely increased autophagy flux. Contrarily, pristine C₆₀ fullerene had no modulatory effect on all studied apoptotic and autophagy markers in non-diabetic groups. Therefore, oil extracted C₆₀ fullerene exhibits cytoprotective effect in hyperglycemia-stressed hippocampal cells. The presented results confirm that pristine C₆₀ fullerene nanoparticles can protect hippocampal cells against hyperglycemic stress via anti-oxidant, anti-apoptotic effects and amelioration of autophagy flux. Moreover, C₆₀ fullerene regulates a balance of autophagy via BCL-2/Beclin-1 reciprocal expression that could prevent functional disturbances in hippocampus.

Licochalcone B Ameliorates Liver Cancer via Targeting of Apoptotic Genes, DNA Repair Systems, and Cell Cycle Control

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a ubiquitous multifunctional protein required in the DNA base excision repair pathway and a noteworthy reducing-oxidizing factor that regulates the activity of various transcription factors. Cyclin-dependent kinases (CDKs) assume a key role in directing the progression of the cell- cycle. The present study evaluated the synergistic efficacy of using licochalcone B (LCB) and fullerene C60 (FnC60) nanoparticles against diethylnitrosamine (DEN)-induced hepatocarcinoma in rats and relevant signaling pathways, with APE1/Ref-1 and CDK-4, as novel anti-cancer- targeting. LCB alone and in combination with FnC60 significantly decreased DNA fragmentation, oxidative DNA damage (8-hydroxy-2'-deoxyguanosine levels), APE1/Ref-1, CDK-4, retinoblastoma, B- cell lymphoma-2 (Bcl-2), B-cell lymphoma-xL (Bcl-xL), and β-arrestin-2 mRNA expression, and APE1/Ref-1 and CDK-4 protein expression. In contrast, these treatments significantly increased the expression of protein 53 (p53), Bcl-2-associated X protein (Bax), and caspase-3. These data suggest that LCB either alone or in combination with FnC60 elicited significant protective effects against DEN-induced hepatocarcinogenesis, which may have occurred because of the regulation of enzymes involved in DNA repair and cell-cycle control at S phase progression as well as the induction of apoptosis at the gene and protein expression levels. Furthermore, FnC60 potentiated the effect of LCB at the molecular level, possibly through targeting of cancerous cells.

C60 Fullerenes Suppress Reactive Oxygen Species Toxicity Damage in Boar Sperm

We report the carboxylated C₆₀ improved the survival and quality of boar sperm during liquid storage at 4 °C and thus propose the use of carboxylated C₆₀ as a novel antioxidant semen extender supplement. Our results demonstrated that the sperm treated with 2 μg mL^-1 carboxylated C₆₀ had higher motility than the control group (58.6% and 35.4%, respectively; P ˂ 0.05). Moreover, after incubation with carboxylated C₆₀ for 10 days, acrosome integrity and mitochondrial activity of sperm increased by 18.1% and 34%, respectively, compared with that in the control group. Similarly, the antioxidation abilities and adenosine triphosphate levels in boar sperm treated with carboxylated C₆₀ significantly increased (P ˂ 0.05) compared with those in the control group. The presence of carboxylated C₆₀ in semen extender increases sperm motility probably by suppressing reactive oxygen species (ROS) toxicity damage. Interestingly, carboxylated C₆₀ could protect boar sperm from oxidative stress and energy deficiency by inhibiting the ROS-induced protein dephosphorylation via the cAMP-PKA signaling pathway. In addition, the safety of carboxylated C₆₀ as an alternative antioxidant was also comprehensively evaluated by assessing the mean litter size and number of live offspring in the carboxylated C₆₀ treatment group. Our findings confirm carboxylated C₆₀ as a novel antioxidant agent and suggest its use as a semen extender supplement for assisted reproductive technology in domestic animals.

Recent Status of Nanomaterial Fabrication and Their Potential Applications in Neurological Disease Management

Nanomaterials (NMs) are receiving remarkable attention due to their unique properties and structure. They vary from atoms and molecules along with those of bulk materials. They can be engineered to act as drug delivery vehicles to cross blood-brain barriers (BBBs) and utilized with better efficacy and safety to deliver specific molecules into targeted cells as compared to conventional system for neurological disorders. Depending on their properties, various metal chelators, gold nanoparticles (NPs), micelles, quantum dots, polymeric NPs, liposomes, solid lipid NPs, microparticles, carbon nanotubes, and fullerenes have been utilized for various purposes including the improvement of drug delivery system, treatment response assessment, diagnosis at early stage, and management of neurological disorder by using neuro-engineering. BBB regulates micro- and macromolecule penetration/movement, thus protecting it from many kinds of illness. This phenomenon also prevents drug delivery for the neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis, amyotrophic lateral sclerosis, and primary brain tumors. For some neurological disorders (AD and PD), the environmental pollution was considered as a major cause, as observed that metal and/or metal oxide from different sources are inhaled and get deposited in the lungs/brain. Old age, obesity, diabetes, and cardiovascular disease are other factors for rapid deterioration of human health and onset of AD. In addition, gene mutations have also been examined to cause the early onset familial forms of AD. AD leads to cognitive impairment and plaque deposits in the brain leading to neuronal cell death. Based on these facts and considerations, this review elucidates the importance of frequently used metal chelators, NMs and/or NPs. The present review also discusses the current status and future challenges in terms of their application in drug delivery for neurological disease management.

Nanomedicine in Central Nervous System (CNS) Disorders: A Present and Future Prospective

Purpose: For the past few decades central nervous system disorders were considered as a major strike on human health and social system of developing countries. The natural therapeutic methods for CNS disorders limited for many patients. Moreover, nanotechnology-based drug delivery to the brain may an exciting and promising platform to overcome the problem of BBB crossing. In this review, first we focused on the role of the blood-brain barrier in drug delivery; and second, we summarized synthesis methods of nanomedicine and their role in different CNS disorder. Method: We reviewed the PubMed databases and extracted several kinds of literature on neuro nanomedicines using keywords, CNS disorders, nanomedicine, and nanotechnology. The inclusion criteria included chemical and green synthesis methods for synthesis of nanoparticles encapsulated drugs and, their in-vivo and in-vitro studies. We excluded nanomedicine gene therapy and nanomaterial in brain imaging. Results: In this review, we tried to identify a highly efficient method for nanomedicine synthesis and their efficacy in neuronal disorders. SLN and PNP encapsulated drugs reported highly efficient by easily crossing BBB. Although, these neuro-nanomedicine play significant role in therapeutics but some metallic nanoparticles reported the adverse effect on developing the brain. Conclusion: Although impressive advancement has made via innovative potential drug development, but their efficacy is still moderate due to limited brain permeability. To overcome this constraint,powerful tool in CNS therapeutic intervention provided by nanotechnology-based drug delivery methods. Due to its small and biofunctionalization characteristics, nanomedicine can easily penetrate and facilitate the drug through the barrier. But still, understanding of their toxicity level, optimization and standardization are a long way to go.

Carbon Nanomaterials Interfacing with Neurons: An In vivo Perspective

Developing new tools that outperform current state of the art technologies for imaging, drug delivery or electrical sensing in neuronal tissues is one of the great challenges in neurosciences. Investigations into the potential use of carbon nanomaterials for such applications started about two decades ago. Since then, numerous in vitro studies have examined interactions between these nanomaterials and neurons, either by evaluating their compatibility, as vectors for drug delivery, or for their potential use in electric activity sensing and manipulation. The results obtained indicate that carbon nanomaterials may be suitable for medical therapies. However, a relatively small number of in vivo studies have been carried out to date. In order to facilitate the transformation of carbon nanomaterial into practical neurobiomedical applications, it is essential to identify and highlight in the existing literature the strengths and weakness that different carbon nanomaterials have displayed when probed in vivo. Unfortunately the current literature is sometimes sparse and confusing. To offer a clearer picture of the in vivo studies on carbon nanomaterials in the central nervous system, we provide a systematic and critical review. Hereby we identify properties and behavior of carbon nanomaterials in vivo inside the neural tissues, and we examine key achievements and potentially problematic toxicological issues.

The role of low levels of fullerene C60 nanocrystals on enhanced learning and memory of rats through persistent CaMKII activation

Engineered nanomaterials are known to exhibit diverse and sometimes unexpected biological effects. Fullerene nanoparticles have been reported to specifically bind to and elicit persistent activation of hippocampal Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), a multimeric intracellular serine/threonine kinase central to Ca(2+) signal transduction and critical for synaptic plasticity, but the functional consequence of that modulation is unknown. Here we show that low doses of fullerene C60 nanocrystals (Nano C60), delivered through intrahippocampal infusion and without any obvious cytotoxicity in hippocampal neuronal cells, enhance the long-term potentiation (LTP) of rats. Intraperitoneal injection of 320 μg/kg of Nano C60, once daily for 10 days, also enhanced spatial memory of rats in addition to an increase of LTP. In parallel, both the IH and IP administration of Nano C60 increased the autonomous activity and the level of threonine 286 (T286) autophosphorylation of CaMKII, enhanced post-synaptic AMPA/NMDA ratio, and triggered time-dependent activation of ERK and CREB. Our results reveal a striking and highly unexpected ability of Nano C60 in positively modulating learning and memory, an effect that is most likely manifested through locking CaMKII in an active conformation, and may have significant implications for the potential therapeutic applications of fullerene C60, a classic engineered nanomaterial.

Polyhydroxyfullerene binds cadmium ions and alleviates metal-induced oxidative stress in Saccharomyces cerevisiae

The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast Saccharomyces cerevisiae by exposing cells to Cd (≤5 mg liter(-1)) in the absence or presence of PHF (≤500 mg liter(-1)) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.

Induction of Inflammatory Responses by Carbon Fullerene (C60) in Cultured RAW264.7 Cells and in Intraperitoneally Injected Mice

As the use of carbon fullerene increases in the chemical industry, the concern over its biological and toxicological effects is also increasing. In this study, the suspension of carbon fullerene (C60) in phosphate buffered saline was prepared and toxicity was investigated using cultured RAW 264.7 and in intraperitoneally injected mice, respectively. The average size of carbon fullerene in the suspension was 53.7 ± 26.5 nm when determined by particle size analyzer. Cell viability was significantly decreased by the exposure of carbon fullerene (0.25~2.00 μg/ml) for 96 hrs in the cultured RAW 264.7 cells. Intracellular reduced glutathione (GSH) level was also decreased compared to the level of the non-treated control group during the exposure period, while the level of nitric oxide was increased. When mice were intraperitoneally injected with carbon fullerene, serum cytokine levels of IL-1 and IL-6 were increased with the increased expression of inflammatory genes in peritoneal macrophage and T cell distribution in blood lymphocytes.The results suggested inflammatory responses were induced by carbon fullerene.

Nanotechnology in Neurosurgery

Clinical neurology and neurosurgery are two fields that face some of the most challenging and exciting problems remaining in medicine. Brain tumors, paralysis after trauma or stroke, and neurodegerative diseases are some of the many disorders for which effective therapies remain elusive. Nanotechnology seems poised to offer promising new solutions to some of these difficult problems. The latest advances in materials engineered at the nanoscale for applications relevant to the clinical neurosciences, such as medical imaging, nanotherapies for neurologic disease, nerve tissue engineering, and nanotechnological contributions to neuroelectrodes and brain-machine interface technology are reviewed. The primary classes of materials discussed include superparamagnetic iron oxide nanoparticles, gold nanoparticles, liposomes, carbon fullerenes, and carbon nanotubes. The potential of the field and the challenges that must be overcome for the current technology to become available clinically are highlighted.

Intrinsic biological property of colloidal fullerene nanoparticles (nC60): lack of lethality after high dose exposure to human epidermal and bacterial cells

Colloidal fullerene nanoparticles (nC60) were reported to be toxic to fish brains, human cells and microorganisms, while new observations suggest that the observed toxicity may be due to tetrahydrofuran (THF) solvent or its oxidative by-products in nC60 preparations. Here, we report a novel method for preparing nC60 nanoparticles that does not use THF solvent, but provides nC60 with an average particle size of 43.8 nm and a yield approximately 100 times higher than the THF method. The prepared nC60 showed a similar antioxidant capacity compared to a water-soluble vitamin E analog. No mortality to human epidermal keratinocytes was observed at a concentration 170 times higher than the reported LC50 values for other human cell lines. No toxicity was observed to E. coli or B. subtilis at up to 342 microg/mL nC60 for 16 h, which was hundred times higher than the reported minimum inhibitory concentrations of nC60 prepared using THF method for these two bacteria. When E. coli was exposed to 85.5 microg/mL nC60 with daily passage for 4 days, the stationary phase populations at different passages were not statistically different (p = 0.05) from the control without nC60 nanoparticles. These results reveal that the intrinsic biological property of nC60 is non-toxic, confirming the prior non-toxic reports when using nC60 prepared with non-THF methods.

Optical heating and rapid transformation of functionalized fullerenes

Irradiating single-walled carbon nanotubes can lead to heat generation or ignition. These processes could be used in medical and industrial applications, but the poor solvent compatibility and high aspect ratios of nanotubes have led to concerns about safety. Here, we show that certain functionalized fullerenes, including polyhydroxy fullerenes (which are known to be environmentally safe and to have therapeutic properties) are heated or ignited by exposure to low-intensity (<10(2 ) W cm(-2)) continuous-wave laser irradiation. We also show that polyhydroxy fullerenes and other functionalized fullerenes can be transformed into single-walled nanotubes, multiwalled nanotubes and carbon onions without the presence of a catalyst by exposure to low-intensity laser irradiation in an oxygen-free environment. To demonstrate the potential usefulness of these processes in applications, we disrupted animal cells dosed with polyhydroxy fullerenes by exposing them to a near-infrared laser for a few seconds, and also ignited an explosive charge in contact with a particle of carboxy fullerenes.

The biological mechanisms and physicochemical characteristics responsible for driving fullerene toxicity

This review provides a comprehensive critical review of the available literature purporting to assess the toxicity of carbon fullerenes. This is required as prior to the widespread utilization and production of fullerenes, it is necessary to consider the implications of exposure for human health. Traditionally, fullerenes are formed from 60 carbon atoms, arranged in a spherical cage-like structure. However, manipulation of surface chemistry and molecular makeup has created a diverse population of fullerenes, which exhibit drastically different behaviors. The cellular processes that underlie observed fullerene toxicity will be discussed and include oxidative, genotoxic, and cytotoxic responses. The antioxidant/cytoprotective properties of fullerenes (and the attributes responsible for driving these phenomena) have been considered and encourage their utilization within the treatment of oxidant-mediated disease. A number of studies have focused on improving the water solubility of fullerenes in order to enable their exploitation within biological systems. Manipulating fullerene water solubility has included the use of surface modifications, solvents, extended stirring, and mechanical processes. However, the ability of these processes to also impact on fullerene toxicity requires assessment, especially when considering the use of solvents, which particularly appear to enhance fullerene toxicity. A number of the discussed investigations were not conducted to reveal if fullerene behavior was due to their nanoparticle dimensions but instead addressed the biocompatibility and toxicity of fullerenes. The hazards to human health, associated with fullerene exposure, are uncertain at this time, and further investigations are required to decipher such effects before an effective risk assessment can be conducted.

Peculiarities of the antioxidant and radioprotective effects of hydrated C60 fullerene nanostuctures in vitro and in vivo

Aqueous solutions of highly stable supramolecular donor-acceptor complexes of chemically nonmodified pristine C(60) fullerene molecules with H(2)O molecules (hydrated C(60) fullerene-C(60)HyFn) and their labile nano-sized clusters were examined for their antioxidant effects on removal of hydroxyl radicals (.OH) and protecting DNA against oxidative damage induced by ionizing radiation in vitro. The suppressing influence of C(60)HyFn on the formation of OH-radicals in water exposed to X-rays at doses of 1-7 Gy was assessed by determination of oxidation levels of coumarin-3-carboxylic acid. C(60)HyFn demonstrates apparent antiradical activity in vitro in the range of concentrations of 10(-11)-10(-6) M. Paradoxically, the .OH-removing efficacy of C(60)HyFn was in reverse correlation with fullerene concentration. It was hypothesized that the antiradical action of C(60)HyFn in water medium generally is due to a "nonstoichiometric" mechanism, supposedly to a hydrated free radical recombination (self-neutralization), which is catalyzed by specific water structures ordered by C(60)HyFn. With the use of 8-oxoguanine as a marker of oxidative damage to DNA, it has been demonstrated that C(60)HyFn in concentrations of 10(-7)-10(-6) M protects nucleic acids against radical-induced damage. The second part of the present study was aimed to evaluate the overall radioprotective efficacy of C(60)HyFn in doses of 0.1 or 1 mg/kg b.w. injected intraperitoneally to mice either 1 h before or 15 min after lethal dose exposure of the X-ray (7 Gy) irradiation. Survival rate of the mice was observed at 30 day intervals after irradiation, while the weight gains of experimental animals were monitored as well. The most significant protective effect was demonstrated when 1 mg/kg dosage of C(60)HyFn was administered before irradiation. The outcome of the substance testing is 15% survival rate of irradiated animals at 30 days of observation, and prevention of noticeable weight loss characteristic for radiation impact, versus unprotected control animals. In conclusion, results of the study obviate that the apparent protective action of C(60)HyFn in vivo is determined by its considerable ability to decrease X-ray-generated reactive oxygen species. Based on the results and that neat C(60) is nontoxic, actually in the hydrated form, without side effects and with sufficient radioprotective effects in low doses, C(60)HyFn may be considered as a novel antioxidant agent, which substantially diminishes the harmful effects of ionizing radiation.