C(60) and water-soluble fullerene derivatives as antioxidants against radical-initiated lipid peroxidation

Reaction mechanism with indano[60]fullerene bromide for evaporable fullerene derivatives

Indano[60]fullerene bromide was isolated as a key intermediate in the synthesis of indano[60]fullerene ketone, an evaporable fullerene derivative. Based on the identified reaction mechanism, aqueous hydrobromic acid was used to achieve reproducible and high-yielding reactions. A scalable one-pot reaction from aryl[60]fullerenyl dimers to indano[60]fullerene ketone was also demonstrated.

NHC-BH2-C60H: synthesis, characterization and electrochemical properties of the N-heterocyclic-carbene-stabilized fullerene-borane complex

NHC-[60]fullereborane (NHC-BH2-C60H) has been synthesized, isolated in pure form, and characterized. The reaction of C60 with NHC-borane produced NHC-BH2-C60H as the first air-stable and separatable fullerene-borane compound. The formation of a N-heterocyclic carbene stabilized this borane complex of C60, and the structure of the complex was unambiguously determined throughsingle-crystal X-ray analysis. This fullerene-borane complex exhibited remarkable stability and promising electrochemical properties.

Buckyballs to fight pandemic: Water-soluble fullerene derivatives with pendant carboxylic groups emerge as a new family of promising SARS-CoV-2 inhibitors

Herein, we present the first experimental study of individual water-soluble fullerene derivatives proving their ability to inhibit SARS-CoV-2 in vitro. The initial screening allowed us to identify a few new compounds that have demonstrated pronounced antiviral activity with IC50 values as low as 390 nM and selectivity indexes reaching 214. Time-of-addition analysis and molecular docking results suggested that the viral protease and/or the spike protein are the most probable targets inhibited by the fullerene derivatives. Further rational design of fullerene derivatives might lead to the development of compounds with further enhanced antiviral activity and decreased toxicity.

Highly Water-Dispersed Natural Fullerenes Coated with Pluronic Polymers as Novel Nanoantioxidants for Enhanced Antioxidant Activity

Fullerene is a cosmic material with a buckyball-like structure comprising 60 carbon atoms. It has attracted significant interest because of its outstanding antioxidant, antiviral, and antibacterial properties. Natural fullerene (NC60) in shungite meets the demand of biomedical fields to scavenge reactive oxygen species in many diseases. However, its hydrophobicity and poor solubility in water hinder its use as an antioxidant. In this study, highly water-dispersed and stable Pluronic-coated natural fullerene nanoaggregates (NC60/Plu) were prepared from various Pluronic polymers. The water dispersity and stability of NC60 were compared and optimized based on the characteristics of Pluronic polymers including F68, F127, L35, P123, and L81. In particular, NC60 coated with Pluronic F127 at a weight ratio of 1 to 5 showed excellent antioxidant effects both in situ and in vitro. This suggests that the high solubilization of NC60 in Pluronic polymers increases its chance of interacting with reactive oxygen radicals and improves radical scavenging activity. Thus, the optimized NC60/PF127 may be a novel biocompatible antioxidant for treating various diseases associated with oxidative stress.

Reactive oxygen species-scavenging nanomaterials for the prevention and treatment of age-related diseases

With increasing proportion of the elderly in the population, age-related diseases (ARD) lead to a considerable healthcare burden to society. Prevention and treatment of ARD can decrease the negative impact of aging and the burden of disease. The aging rate is closely associated with the production of high levels of reactive oxygen species (ROS). ROS-mediated oxidative stress in aging triggers aging-related changes through lipid peroxidation, protein oxidation, and DNA oxidation. Antioxidants can control autoxidation by scavenging free radicals or inhibiting their formation, thereby reducing oxidative stress. Benefiting from significant advances in nanotechnology, a large number of nanomaterials with ROS-scavenging capabilities have been developed. ROS-scavenging nanomaterials can be divided into two categories: nanomaterials as carriers for delivering ROS-scavenging drugs, and nanomaterials themselves with ROS-scavenging activity. This study summarizes the current advances in ROS-scavenging nanomaterials for prevention and treatment of ARD, highlights the potential mechanisms of the nanomaterials used and discusses the challenges and prospects for their applications.

Research progress of fullerenes and their derivatives in the field of PDT

In contemporary studies, the predominant utilization of C60 derivatives pertains to their role as photosensitizers or agents that scavenge free radicals. The intriguing coexistence of these divergent functionalities has prompted extensive investigation into water-soluble fullerenes. The photodynamic properties of these compounds find practical applications in DNA cleavage, antitumor interventions, and antibacterial endeavors. Consequently, photodynamic therapy is progressively emerging as a pivotal therapeutic modality within the biomedical domain, owing to its notable levels of safety and efficacy. The essential components of photodynamic therapy encompass light of the suitable wavelength, oxygen, and a photosensitizer, wherein the reactive oxygen species generated by the photosensitizer play a pivotal role in the therapeutic mechanism. The remarkable ability of fullerenes to generate singlet oxygen has garnered significant attention from scholars worldwide. Nevertheless, the limited permeability of fullerenes across cell membranes owing to their low water solubility necessitates their modification to enhance their efficacy and utilization. This paper reviews the applications of fullerene derivatives as photosensitizers in antitumor and antibacterial fields for the recent years.

Application of carbon nanostructures in biomedicine: realities, difficulties, prospects

The review systematizes data on the wide possibilities of practical application of carbon nanostructures. Much attention is paid to the use of carbon nanomaterials in medicine for the visualization of tumors during surgical interventions, in the creation of cosmetics, as well as in agriculture in the creation of fertilizers. Additionally, we demonstrate trends in research in the field of carbon nanomaterials with a view to elaborating targeted drug delivery systems. We also show the creation of nanosized medicinal substances and diagnostic systems, and the production of new biomaterials. A separate section is devoted to the difficulties in studying carbon nanomaterials. The review is intended for a wide range of readers, as well as for experts in the field of nanotechnology and nanomedicine.

Synthesis of spiro[indolenine]-methanofullerenes via Deoxofluor promoted deoxygenative cyclopropanation of 1,2-(3-indole)-fullerenols

Deoxofluor-promoted intramolecular cyclopropanation of 1,2-(3-indole)fullerenols has been developed as a straightforward and efficient protocol for the synthesis of various spiro[indolenine]-methanofullerenes. This approach exhibits low cost, operational simplicity, and convenient conditions, and thus has potential application value.

The effect of C60 fullerene on the mechanokinetics of muscle gastrocnemius contraction in chronically alcoholized rats

The C60 fullerene effect (oral administration at a dose of 1 mg kg-1) on the selected biomechanical parameters of muscle gastrocnemius contraction, biochemical indicators of blood and muscle tissue as well as histological changes in rat muscle tissue after chronic alcoholization for 3, 6 and 9 months was studied in detail. Water-soluble C60 fullerenes were shown to reduce the pathological processes development in the muscle apparatus by an average of (35-40)%. In particular, they reduced the time occurrence of fatigue processes in muscle during the long-term development of alcoholic myopathy and inhibited oxidative processes in muscle, thereby preventing its degradation. These findings open up the possibility of using C60 fullerenes as potent antioxidants for the correction of the pathological conditions of the muscle system arising from alcohol intoxication.

Nanomaterials and Their Impact on the Immune System

Nanomaterials have been the focus of intensive development and research in the medical and industrial sectors over the past several decades. Some studies have found that these compounds can have a detrimental impact on living organisms, including their cellular components. Despite the obvious advantages of using nanomaterials in a wide range of applications, there is sometimes skepticism caused by the lack of substantial proof that evaluates potential toxicities. The interactions of nanoparticles (NPs) with cells of the immune system and their biomolecule pathways are an area of interest for researchers. It is possible to modify NPs so that they are not recognized by the immune system or so that they suppress or stimulate the immune system in a targeted manner. In this review, we look at the literature on nanomaterials for immunostimulation and immunosuppression and their impact on how changing the physicochemical features of the particles could alter their interactions with immune cells for the better or for the worse (immunotoxicity). We also look into whether the NPs have a unique or unexpected (but desired) effect on the immune system, and whether the surface grafting of polymers or surface coatings makes stealth nanomaterials that the immune system cannot find and get rid of.

Recent Development of Nano-Carbon Material in Pharmaceutical Application: A Review

Carbon nanomaterials have attracted researchers in pharmaceutical applications due to their outstanding properties and flexible dimensional structures. Carbon nanomaterials (CNMs) have electrical properties, high thermal surface area, and high cellular internalization, making them suitable for drug and gene delivery, antioxidants, bioimaging, biosensing, and tissue engineering applications. There are various types of carbon nanomaterials including graphene, carbon nanotubes, fullerenes, nanodiamond, quantum dots and many more that have interesting applications in the future. The functionalization of the carbon nanomaterial surface could modify its chemical and physical properties, as well as improve drug loading capacity, biocompatibility, suppress immune response and have the ability to direct drug delivery to the targeted site. Carbon nanomaterials could also be fabricated into composites with proteins and drugs to reduce toxicity and increase effectiveness in the pharmaceutical field. Thus, carbon nanomaterials are very effective for applications in pharmaceutical or biomedical systems. This review will demonstrate the extraordinary properties of nanocarbon materials that can be used in pharmaceutical applications.

Preparation and Evaluation of the Cytoprotective Activity of Micelles with DSPE-PEG-C60 as a Carrier Against Doxorubicin-Induced Cytotoxicity

To deliver doxorubicin (DOX) with enhanced efficacy and safety in vivo, fullerenol-modified micelles were prepared with the amphiphilic polymer DSPE-PEG-C60 as a carrier, which was synthesized by linking C60(OH)22 with DSPE-PEG-NH2. Studies of its particle size, PDI, zeta potential, and encapsulation efficiency were performed. DOX was successfully loaded into the micelles, exhibiting a suitable particle size [97 nm, 211 nm, 260 nm, vector: DOX = 5:1, 10:1; 15:1 (W/W)], a negative zeta potential of around -30 mv, and an acceptable encapsulation efficiency [86.1, 95.4, 97.5%, vector: DOX = 5:1, 10:1; 15:1 (W/W)]. The release behaviors of DOX from DSPE-PEG-C60 micelles were consistent with the DSPE-PEG micelles, and it showed sustained release. There was lower cytotoxicity of DSPE-PEG-C60 micelles on normal cell lines (L02, H9c2, GES-1) than free DOX and DSPE-PEG micelles. We explored the protective role of DSPE-PEG-C60 on doxorubicin-induced cardiomyocyte damage in H9c2 cells, which were evaluated with a reactive oxygen species (ROS) assay kit, JC-1, and an FITC annexin V apoptosis detection kit for cellular oxidative stress, mitochondrial membrane potential, and apoptosis. The results showed that H9c2 cells exposed to DSPE-PEG-C60 micelles displayed decreased intracellular ROS, an increased ratio of red fluorescence (JC-1 aggregates) to green fluorescence (JC-1 monomers), and a lower apoptotic ratio than the control and DSPE-PEG micelle cells. In conclusion, the prepared DOX-loaded DSPE-PEG-C60 micelles have great promise for safe, effective tumor therapy.

How fullerene derivatives (FDs) act on therapeutically important targets associated with diabetic diseases

•

Five proteins related to diabetic disease were selected from Protein Data Bank.

•

Binding scores were calculated for five proteins with 169 fullerene derivatives.

•

Correlation between drug-like descriptors and binding scores activity was examined.

•

The contribution of descriptors to protein-ligand binding was demonstrated.

•

The QSARs models for prediction of binding scores activity were built.

Fullerene derivatives (FDs) belong to a relatively new family of nano-sized organic compounds. They are widely applied in materials science, pharmaceutical industry, and (bio) medicine. This research focused on the study of FDs in terms of their potential inhibitory effect on therapeutic targets associated with diabetic disease, as well as analysis of protein–ligand binding in order to identify the key binding characteristics of FDs.

Therapeutic drug compounds when entering the biological system usually inevitably encounter and interact with a vast variety of biomolecules that are responsible for many different functions in organisms. Protein biomolecules are the most important functional components and used in this study as target structures. The structures of proteins [(PDB ID: 1BMQ, 1FM6, 1GPB, 1H5U, 1US0)] belonging to the class of anti-diabetes targets were obtained from the Protein Data Bank (PDB). Protein binding activity data (binding scores) were calculated for the dataset of 169 FDs related to these five proteins. Subsequently, the resulting data were analyzed using various machine learning and cheminformatics methods, including artificial neural network algorithms for variable selection and property prediction.

The Quantitative Structure-Activity Relationship (QSAR) models for prediction of binding scores activity were built up according to five Organization for Economic Co-operation and Development (OECD) principles.

All the data obtained can provide important information for further potential use of FDs with different functional groups as promising medical antidiabetic agents. Binding scores activity can be used for ranking of FDs in terms of their inhibitory activity (pharmacological properties) and potential toxicity.

Adducts of Lower Fullerenes and Amino Acids: Synthesis, Identification, and Quantum-Mechanical Modeling of Their Physicochemical Properties

Abstract

Different ways of synthesizing bis-, tris-, and octakis-adducts of C60 and C70 lower fullerenes are considered, and their yield and purity are described. The adducts are identified by physicochemical means: elemental analysis, IR, electron spectroscopy, Raman spectroscopy, HPLC, mass spectrometry, and complex thermal analysis. Their physicochemical properties are modeled using computers, density functional theory, and molecular dynamics at the atomic-molecular level.

The effect of water-soluble pristine C60 fullerene on 6-OHDA-induced Parkinson’s disease in rats

Oxidative stress is thought to be one of the mechanisms that leads to the dysfunction and degeneration of dopaminergic neurons in Parkinson’s disease pathogenesis and presumed to be underway during the prodromal phase. Therefore, therapy, which is effective against pre-motor symptoms, might be effective in preventing or delaying the development and progression of Parkinson’s disease. The aim of our study was to investigate the therapeutic efficiency of pristine C60 fullerene aqueous solution (C60FAS) during Parkinson’s disease in rats. The unilateral dopamine deficiency was induced in male Wistar rats (220–250 g) by stereotaxic microinjection of neurotoxin 6-hydroxydopamine (6-OHDA, 12 μg). C60FAS was injected to rats intraperitoneally daily for 10 days (0.65 mg/kg per day). The percentage of destroyed dopaminergic neurons was determined by the apomorphine test and by IHC staining of tyrosine hydroxylase-positive neurons in substantia nigra. We evaluated the rat body weight, the water and food intake, Open Field behavioural test, the level of biochemical antioxidant system, the activity of peritoneal macrophages. Levels of spontaneous and carbachol-stimulated colon motility were estimated by ballonographic method in vivo. C60FAS showed a positive tendency to increase the number of tyrosine hydroxylase-positive cells in the midbrain, which was associated with more profound improvement in apomorphine-rotation behaviour and slight relief of the anxiety level in Open Field test. Furthermore, C60FAS treatment increased the index of stimulated distal colon motor activity while it did not have a significant effect on water content in feces and total gastrointestinal transit time. C60FAS treatment did not affect water intake behaviour or body weight changes while it induced an increase of glutathione level and decrease activity of glutathione peroxidase in the brain as well as an increase in activity of peritoneal macrophages in 6-OHDA-Parkinson’s disease rats. These findings confirmed the potential therapeutic effectiveness of water-soluble pristine C60 fullerene in Parkinson’s disease pathogenesis, though there is ground for caution because of its systemic mild toxic effect.

Antioxidant Potential of Aqueous Dispersions of Fullerenes C60, C70, and Gd@C82

The antioxidant potential (capacity and activity) of aqueous fullerene dispersions (AFD) of non-functionalized C60, C70, and Gd@C82 endofullerene (in micromolar concentration range) was estimated based on chemiluminescence measurements of the model of luminol and generation of organic radicals by 2,2'-azobis(2-amidinopropane) dihydrochloride (ABAP). The antioxidant capacity was estimated by the TRAP method, from the concentration of half-suppression, and from the suppression area in the initial period. All three approaches agree and show that the antioxidant capacity of AFDs increased in the order Gd@C82 < C70 < C60. Mathematical modeling of the long-term kinetics data was used for antioxidant activity estimation. The effect of C60 and C70 is found to be quenching of the excited product of luminol with ABAP-generated radical and not an actual antioxidant effect; quenching constants differ insignificantly. Apart from quenching with a similar constant, the AFD of Gd@C82 exhibits actual antioxidant action. The antioxidant activity in Gd@C82 is 300-fold higher than quenching constants.

High Temperature Accelerated Stone-Wales Transformation and the Threshold Temperature of IPR-C60 Formation

The Stone-Wales bond rotation isomerization of nonicosahedral C₆₀ (C_2v-C₆₀) into isolated-pentagon rule following icosahedral C₆₀ (I_h-C₆₀ or IPR-C₆₀) is a limiting step in the synthesis of I_h-C₆₀. However, extensive previous studies indicate that the potential energy barrier of the Stone-Wales bond rotation is between 6 and 8 eV, extremely high to allow for bond rotation at the temperatures used to produce fullerenes conventionally. This is also despite data indicating a possible fullerene road mechanism that necessitates low-temperature annealing. However, these previous investigations often have limiting factors, such as using the harmonic approximation to determine free energies at high temperatures or considering only the reverse I_h-C₆₀ to C_2v-C₆₀ transition as a basis. Indeed, when the difference in energy between I_h-C₆₀ and C_2v-C₆₀ is accounted for, this barrier is generally reduced by ∼1.5 eV. Thus, utilizing the recently developed density functional tight binding metadynamics (DFTB-MTD) interface, the effects of temperature on the bond rotation in the conversion of C_2v-C₆₀ to I_h-C₆₀ have been investigated. We found that Stone-Wales bond rotations are complex processes with both in-plane and out-of-plane transition states, and which transition path dominates depends on temperature. Our results clearly show that at temperatures of 2000 K, the free energy for a C_2v-C₆₀ to I_h-C₆₀ transition is only ∼4.21 eV and further reduces to ∼3.77 eV at 3000 K. This translates to transition times of ∼971 μs at 2000 K and ∼34 ns at 3000 K, indicating that defect healing is a fast process at temperatures typical of arc jet or laser ablation experiments. Conversely, below ∼2000 K, bond rotation becomes prohibitively slow, putting a lower threshold limit on the temperature of fullerene formation and subsequent annealing.

Effect of Long-Term Treatment with C60 Fullerenes on the Lifespan and Health Status of CBA/Ca Mice

Several studies claimed C₆₀ fullerenes as a prospective geroprotector drug due to their ability to capture free radicals effectively and caused a profound interest in C₆₀ in life extension communities. Multiple additives are already sold for human consumption despite a small body of evidence supporting the beneficial effects of fullerenes on the lifespan. To test the effect of C₆₀ fullerenes on lifespan and healthspan, we administered C₆₀ fullerenes dissolved in virgin olive oil orally to 10-12 months old CBA/Ca mice of both genders for 7 months and assessed their survival. To uncover C₆₀ and virgin olive effects, we established two control groups: mice treated with virgin olive oil (vehicle) and mice treated with drinking water. To measure healthspan, we conducted daily monitoring of health condition and lethality and monthly bodyweight measurements. We also assessed physical activity, glucose metabolism, and hematological parameters every 3 months. We did not observe health deterioration in the animals treated with C₆₀ compared with the control groups. Treatment of mice with C₆₀ fullerenes resulted in an increased lifespan of males and females compared with the olive oil-treated animals. The lifespan of C₆₀-treated mice was similar to the mice treated with water. These results suggest that the lifespan-extending effect in C₆₀-treated mice appears due to the protective effect of fullerenes in opposition to the negative effect of olive oil in CBA/Ca mice.

Evaluation of the C60 biodistribution in mice in a micellar ExtraOx form and in an oil solution

The article is devoted to the study of the pharmacokinetics of fullerene C₆₀ in oil and micellar forms, analysis of its content in blood, liver, lungs, kidneys, heart, brain, adrenal glands, thymus, testicles, and spleen. The highest accumulation of C₆₀ was found in the liver and adrenal glands. As a result of the studies carried out, it was shown that the bioavailability of C₆₀ in the micellar form is higher than that in an oil solution.

C60 in olive oil causes light-dependent toxicity and does not extend lifespan in mice

C60 is a potent antioxidant that has been reported to substantially extend the lifespan of rodents when formulated in olive oil (C60-OO) or extra virgin olive oil (C60-EVOO). Despite there being no regulated form of C60-OO, people have begun obtaining it from online sources and dosing it to themselves or their pets, presumably with the assumption of safety and efficacy. In this study, we obtain C60-OO from a sample of online vendors, and find marked discrepancies in appearance, impurity profile, concentration, and activity relative to pristine C60-OO formulated in-house. We additionally find that pristine C60-OO causes no acute toxicity in a rodent model but does form toxic species that can cause significant morbidity and mortality in mice in under 2 weeks when exposed to light levels consistent with ambient light. Intraperitoneal injections of C60-OO did not affect the lifespan of CB6F1 female mice. Finally, we conduct a lifespan and health span study in males and females C57BL/6 J mice comparing oral treatment with pristine C60-EVOO and EVOO alone versus untreated controls. We failed to observe significant lifespan and health span benefits of C60-EVOO or EVOO supplementation compared to untreated controls, both starting the treatment in adult or old age. Our results call into question the biological benefit of C60-OO in aging.

Reactions of [60]Fullerene with Acetone under Basic Condition: Nucleophilic Ring Opening of the [5,6]-Cyclopropane in C60 and Formation of the Substituted Methano[60]Fulleroids

The reactions of C₆₀ with acetone were carried out under basic condition in the presence of 1.0 M TBAOH (tetra-n-butylammonium hydroxide) methanol solution and ArCH₂Br (Ar = Ph or o-BrPh), where methano[60]fulleroids with a novel 1,1,4,9,9,25-configuration were obtained and structurally characterized by single crystal diffraction. The product was formed via the ring-opening reaction of the [5,6]-cyclopropane by the nucleophilic addition of MeO^-, which is different from the reactions of other ketones reported previously.

Biocompatibility of a nanocomposite based on Aerosil 380 and carboxylated fullerene C60[C(COOH)2]3

Silica is silicon dioxide, which, depending on the production method, can exist in various amorphous forms with varying specific surface area, particle size, pore volume and size, and, as a result, with different physicochemical and sorption characteristics. The presence of silanol groups on the surface of silicas provides the possibility of its further functionalisation. In addition, the developed specific surface of Aerosil allows to obtain composites with a high content of biologically active substances. In this work, we studied the biocompatibility of a composite based on Aerosil 380 and carboxylated fullerene C₆₀[C(COOH)₂]₃, namely: haemolysis (spontaneous and photoinduced), platelet aggregation, binding to HSA, cyto- and genotoxicity, antiradical activity. Interest in the creation of this nanomaterial is due to the fact that carboxylated fullerenes have potential applications in various fields of biomedicine, including the ability to bind reactive oxygen species, inhibition of tumour development, inactivation of viruses and bacteria. The obtained composite can be used for the immobilisation of various drugs and the further development of drugs for theranostics.

Fullerene translocation through peroxidized lipid membranes

Recent cytotoxicity research suggests that fullerenes can enter the cell and cross the blood-brain barrier. However, the underlying toxicity mechanism behind the penetration of fullerenes through biological membranes is still not well understood. Here we perform coarse-grained molecular dynamics simulations to investigate the interactions of fullerenes and their polar derivatives (Janus) with model regular and peroxidized bilayers. We show that the translocation of fullerenes and their residence time in bulk water vary depending on the bilayer's peroxidation degree and fullerene polarity. The distribution of fullerenes inside the bilayer is mainly determined by the peroxidation degree and the saturation level of lipid acyl chains. The transport of pristine fullerenes through bilayers occurs at nano timescale while the complete diffusion may not be achieved for Janus fullerenes in micro timescale. As for the toxic response of fullerenes in terms of membrane damage, no mechanical disruption of model bilayers is observed throughout the studied simulation times.

Reactive Oxygen Species-Regulating Strategies Based on Nanomaterials for Disease Treatment

Reactive oxygen species (ROS) play an essential role in physiological and pathological processes. Studies on the regulation of ROS for disease treatments have caused wide concern, mainly involving the topics in ROS-regulating therapy such as antioxidant therapy triggered by ROS scavengers and ROS-induced toxic therapy mediated by ROS-elevation agents. Benefiting from the remarkable advances of nanotechnology, a large number of nanomaterials with the ROS-regulating ability are developed to seek new and effective ROS-related nanotherapeutic modalities or nanomedicines. Although considerable achievements have been made in ROS-based nanomedicines for disease treatments, some fundamental but key questions such as the rational design principle for ROS-related nanomaterials are held in low regard. Here, the design principle can serve as the initial framework for scientists and technicians to design and optimize the ROS-regulating nanomedicines, thereby minimizing the gap of nanomedicines for biomedical application during the design stage. Herein, an overview of the current progress of ROS-associated nanomedicines in disease treatments is summarized. And then, by particularly addressing these known strategies in ROS-associated therapy, several fundamental and key principles for the design of ROS-associated nanomedicines are presented. Finally, future perspectives are also discussed in depth for the development of ROS-associated nanomedicines.

Effects of fullerene C60 supplementation on gut microbiota and glucose and lipid homeostasis in rats

The effects of twelve weeks of supplementation with fullerene C₆₀ olive/coconut oil solution on a broad spectrum of parameters in rats were examined. The tissue bioaccumulation of C₆₀ was shown to be tissue-specific, with the liver, heart, and adrenal glands being the organs of the greatest, and the kidney, brain, and spleen being the organs of the smallest accumulation. C₆₀ did not change aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase serum activities level, nor the damage of liver cells DNA. There were no effects of fullerene on prooxidant-antioxidant balance in the liver, kidney, spleen, heart, and brain, nor any visible harmful effects on the liver, heart, aorta, spleen, kidney, and small intestine histology. Fullerene changed the gut microbiota structure towards the bacteria that ameliorate lipid homeostasis, causing a serum triglycerides concentration decrease. However, C₆₀ significantly increased the insulin resistance, serum ascorbate oxidation, and brain malondialdehyde and advanced oxidation protein products level. The deteriorative effects of C₆₀ on the brain and serum could be attributed to the specific physicochemical composition of these tissues, potentiating the C₆₀ aggregation or biotransformation as the key element of its pro-oxidative action.

C60 Fullerene as an Effective Nanoplatform of Alkaloid Berberine Delivery into Leukemic Cells

A herbal alkaloid Berberine (Ber), used for centuries in Ayurvedic, Chinese, Middle-Eastern, and native American folk medicines, is nowadays proved to function as a safe anticancer agent. Yet, its poor water solubility, stability, and bioavailability hinder clinical application. In this study, we have explored a nanosized carbon nanoparticle-C₆₀ fullerene (C₆₀)-for optimized Ber delivery into leukemic cells. Water dispersions of noncovalent C₆₀-Ber nanocomplexes in the 1:2, 1:1, and 2:1 molar ratios were prepared. UV-Vis spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM) evidenced a complexation of the Ber cation with the negatively charged C₆₀ molecule. The computer simulation showed that π-stacking dominates in Ber and C₆₀ binding in an aqueous solution. Complexation with C₆₀ was found to promote Ber intracellular uptake. By increasing C₆₀ concentration, the C₆₀-Ber nanocomplexes exhibited higher antiproliferative potential towards CCRF-CEM cells, in accordance with the following order: free Ber < 1:2 < 1:1 < 2:1 (the most toxic). The activation of caspase 3/7 and accumulation in the sub-G1 phase of CCRF-CEM cells treated with C₆₀-Ber nanocomplexes evidenced apoptosis induction. Thus, this study indicates that the fast and easy noncovalent complexation of alkaloid Ber with C₆₀ improved its in vitro efficiency against cancer cells.

In vitro and in vivo study of the toxicity of fullerenols С60, С70 and С120О obtained by an original two step method

The toxicity of C₆₀(OH)₃₀, C₇₀(OH)₃₀, and C₁₂₀O(OH)_n fullerenols, prepared by a new original method, has been studied. This method allowed us to obtain high-purity fullerenols and eliminate the risks of synthesis of preparations containing insoluble fractions contaminated with impurities such as fullerenes not completely reacted by hydroxylation. All fullerenols were detected inside cultured cells. The MTT assay as well as the analysis of apoptosis and cell cycle showed that С₆₀(ОН)₃₀ and С₇₀(OH)₃₀ are non-toxic for cultured V79 и HeLa cells at concentrations exceeding physiological levels by an order of magnitude. С₁₂₀O(OH)_n caused low toxicity. Studies in Drosophila melanogaster showed that any preparations used did not result in a decreased lifespan or in behavior abnormalities in flies.

C60 fullerenes selectively inhibit BKCa but not Kv channels in pulmonary artery smooth muscle cells

Possessing unique physical and chemical properties, C₆₀ fullerenes are arising as a potential nanotechnological tool that can strongly affect various biological processes. Recent molecular modeling studies have shown that C₆₀ fullerenes can interact with ion channels, but there is lack of data about possible effects of C₆₀ molecule on ion channels expressed in smooth muscle cells (SMC). Here we show both computationally and experimentally that water-soluble pristine C₆₀ fullerene strongly inhibits the large conductance Ca²⁺-dependent K⁺ (BK_Ca), but not voltage-gated K⁺ (K_v) channels in pulmonary artery SMC. Both molecular docking simulations and analysis of single channel activity indicate that C₆₀ fullerene blocks BK_Ca channel pore in its open state. In functional tests, C₆₀ fullerene enhanced phenylephrine-induced contraction of pulmonary artery rings by about 25% and reduced endothelium-dependent acetylcholine-induced relaxation by up to 40%. These findings suggest a novel strategy for biomedical application of water-soluble pristine C₆₀ fullerene in vascular dysfunction.

Striking Effect of Polymer End-Group on C60 Nanoparticle Formation by High Shear Vibrational Milling with Alkyne-Functionalized Poly(2-oxazoline)s

Buckminsterfullerene (C₆₀) has a large potential for biomedical applications. However, the main challenge for the realization of its biomedical application potential is to overcome its extremely low water solubility. One approach is the coformulation with biocompatible water-soluble polymers, such as poly(2-oxazoline)s (PAOx), to form water-soluble C₆₀ nanoparticles (NPs). However, uniform and defined NPs have only been obtained via a thin film hydration method or using cyclodextrin-functionalized PAOx. Here, we report the mechanochemical preparation of defined and stable C₆₀:PAOx NPs by the introduction of a simple alkyne group as a polymer end-group. The presence of this alkyne bond is proven to be crucial in the mechanochemical synthesis of stable, defined sub-100 nm C₆₀:PAOx NPs, with high C₆₀ content up to 8.9 wt %.

Effect of C60 fullerene nanoparticles on the diet-induced obesity in rats

BACKGROUND

Obesity is a growing global health problem. Since increased oxidative stress is one of the key pathological mechanisms underpinning overweight and strongly correlates with progression of obesity-related complications we hypothesized that C₆₀ fullerene nanoparticles, due to their strong antioxidant capacity, could be the promising therapeutic agent in the treatment of this disease. Here we investigated whether the C₆₀ fullerenes can alleviate diet-induced obesity (DIO) and metabolic impairments associated with it.

METHODS

To determine the effect of C₆₀ fullerenes on some nutritional and metabolic parameters, rats were fed either a normal diet (6.7% fat, 15.27 kJ·g^-1) or a high-fat diet (38.8% fat, 28.71 kJ·g^-1) for 70 days and were simultaneously treated per os with pristine C₆₀ fullerene aqueous solution (C₆₀FAS; 0.3 mg·kg^-1 every other day) since the 28^th day from the start of the experiment.

RESULTS

Rats fed with high fat diet had significantly increased body mass index (BMI), levels of insulin, glucose, glycosilated hemoglobin (HbA1c) and serum pro-inflammatory cytokines compared with control rats fed with low-fat chow. C₆₀ fullerenes normalized the metabolic parameters and partially reduced BMI in DIO animals. Pro-inflammatory cytokines (IL-1b, IL-12, INFγ) were also decreased in serum of DIO rats treated with C₆₀ fullerenes while anti-inflammatory cytokines (IL-4, IL-10) were at the control levels. High fat diet caused the increased level of oxidative stress products, and this was accompanied by decreased activity both the superoxide dismutase and catalase, whereas the administration of C₆₀ fullerenes markedly decreased level of oxidative stress and enhanced antioxidant enzyme activities.

CONCLUSION

These data indicate that water-soluble pristine C₆₀ fullerenes reduce chronic inflammation, restore glucose homeostasis as well as positively affects on prooxidant-antioxidant homeostasis. C₆₀ fullerenes could be represented as a promising therapeutic agent in the treatment of obesity and its related complications.

Biocompatible [60]/[70] Fullerenols: Potent Defense against Oxidative Injury Induced by Reduplicative Chemotherapy

Chemotherapy as a conventional cancer treatment suffers from critical systemic side effects, which is generally considered as the consequence of reactive oxygen species (ROS). Fullerenes have been widely studied for their excellent performance in radicals scavenging. In the present study, we report a solid-liquid reaction to synthesize fullerenols and their application as ROS scavengers in chemotherapy protection. The solid-liquid reaction is carried out without catalyst and suitable for mass production. The novel [60]/[70] fullerenols show a high stability in water, and the [70] fullerenols (C₇₀-OH) exhibit radical scavenging capability superior to that of [60] fullerenols (C₆₀-OH) in chemotherapy protection. The mouse model for single and reduplicative chemotherapy-induced liver injury demonstrates their protective effects in the chemotherapeutic process, which is confirmed by histopathological examinations and hematological index. The increase of the hepatic l-glutathione (GSH) level and downregulated expression of the cytochrome P-450 2E1 (CYP2E1) give the possible mechanism associated with the impact of fullerenols on the metabolism of doxorubicin. The novel fullerenols may be promising protective agents to satisfy the demand for future clinical chemotherapy.

Effects of fullerene on lipid bilayers displaying different liquid ordering: a coarse-grained molecular dynamics study

BACKGROUND

The toxic effects and environmental impact of nanomaterials, and in particular of Fullerene particles, are matters of serious concern. It has been reported that fullerene molecules enter the cell membrane and occupy its hydrophobic region. Understanding the effects of carbon-based nanoparticles on biological membranes is therefore of critical importance to determine their exposure risks.

METHODS

We report on a systematic coarse-grained molecular dynamics study of the interaction of fullerene molecules with simple model cell membranes. We have analyzed bilayers consisting of lipid species with different degrees of unsaturation and a variety of cholesterol fractions. Addition of fullerene particles to phase-segregated ternary membranes is also investigated in the context of the lipid raft model for the organization of the cell membrane.

RESULTS

Fullerene addition to lipid membranes modifies their structural properties like thickness, area and internal ordering of the lipid species, as well as dynamical aspects such as molecular diffusion and cholesterol flip-flop. Interestingly, we show that phase-segregating ternary lipid membranes accumulate fullerene molecules preferentially in the liquid-disordered domains promoting phase-segregation and domain alignment across the membrane.

CONCLUSIONS

Lipid membrane internal ordering determines the behavior and distribution of fullerene particle, and this, in turn, determines the influence of fullerene on the membrane. Lipid membranes are good solvents of fullerene molecules, and in particular those with low internal ordering.

GENERAL SIGNIFICANCE

Preference of fullerene molecules to be dissolved in the more disordered hydrophobic regions of a lipid bilayer and the consequent alteration of its phase behavior may have important consequences on the activity of biological cell membranes and on the bioconcentration of fullerene in living organisms.

Structure and Dynamics of a N-Methylfulleropyrrolidine-Mediated Gold Nanocomposite: A Spectroscopic Ruler

A mechanistic understanding of the structure and dynamics of a chemically tunable N-methylfulleropyrrolidine (8-NMFP)-assisted gold nanocomposite and its aggregation via a controllable interparticle interaction is reported as a function of the molar ratio and pH of the medium. Electronic structure calculations adopting density functional theory methods implied electrostatic interactions to play a dominant role between 8-NMFP and citrate-capped gold nanoparticles. MM⁺ molecular mechanics force field computations revealed intermolecular gold-gold interactions, contributing toward the formation of spherical composite aggregates. Corroborating these, optical absorption spectra showed the usual surface plasmon band along with a higher-wavelength feature at ∼600-650 nm, indicative of the aggregated nanocomposite. pH-controlled reversible tuning of the plasmonic features in the composite was evident in a pH interval ∼5-6.8, revealing prevalent interparticle electrostatic interactions. In addition, photoluminescence (PL) and time-correlated single-photon counting studies revealed a strong nanocomposite interaction with a pure fluorescent dye, Rhodamine B, indicating excitation energy transfer from the dye to the composite. The dye upon interaction with the nanocomposite showed a significant quenching of its PL intensity and shortening of lifetime. Energy coupling between the metal nanoparticle composite and the emitting molecular dipole resulted in a long-range surface energy transfer (SET) from the donor dye to the surface plasmon modes of the nanoparticle following a donor-acceptor distance dependence of 1/r⁴. This molecular beacon with correlation between the nanoscale structure and the nonradiative nanometal SET can be used as a spectroscopic/molecular ruler in probing advanced functional materials.

Progress in Understanding Degradation Mechanisms and Improving Stability in Organic Photovoltaics

Understanding the degradation mechanisms of organic photovoltaics is particularly important, as they tend to degrade faster than their inorganic counterparts, such as silicon and cadmium telluride. An overview is provided here of the main degradation mechanisms that researchers have identified so far that cause extrinsic degradation from oxygen and water, intrinsic degradation in the dark, and photo-induced burn-in. In addition, it provides methods for researchers to identify these mechanisms in new materials and device structures to screen them more quickly for promising long-term performance. These general strategies will likely be helpful in other photovoltaic technologies that suffer from insufficient stability, such as perovskite solar cells. Finally, the most promising lifetime results are highlighted and recommendations to improve long-term performance are made. To prevent degradation from oxygen and water for sufficiently long time periods, OPVs will likely need to be encapsulated by barrier materials with lower permeation rates of oxygen and water than typical flexible substrate materials. To improve stability at operating temperatures, materials will likely require glass transition temperatures above 100 °C. Methods to prevent photo-induced burn-in are least understood, but recent research indicates that using pure materials with dense and ordered film morphologies can reduce the burn-in effect.