Metallofullerenols in biomedical applications

Nanotechnology meets radiobiology: Fullerenols and Metallofullerenols as nano-shields in radiotherapy

Despite significant advances in the development of radioprotective measures, the clinical application of radioprotectors and radiomitigators remains limited due to insufficient efficacy and high toxicity of most agents. Additionally, in oncological radiotherapy, these compounds may interfere with the therapeutic effectiveness. Recent progress in nanotechnology highlights fullerenols (FulOHs) and metallofullerenols (Me@FulOHs) as promising candidates for next-generation radioprotectors. These nanostructures possess unique antioxidant properties, demonstrating greater efficacy in rediucing oxidative stress compared to conventional agents. Moreover, their potential to minimize pro-oxidative risks depends on the precise identification of cellular environments and irradiation conditions that optimize their radioprotective effects. In parallel, Me@FulOHs serve as powerful theranostic tools in oncology. Their strong imaging signals enable high-resolution PET and MRI, facilitating early detection and accurate localization of pathogenic alterations. This dual functionality positions Me@FulOHs as key components in advanced radiotherapy. By integrating these nanomaterials with modern theranostic approaches, it is possible to enhance the precision of treatment while minimizing side effects, addressing a critical need in contemporary oncology. This review emphasizes the importance of systematic evaluation of context-dependent effects of Me@FulOHs, particularly in pre- and post-irradiation scenarios, to optimize their clinical relevance. The dual role of Me@FulOHs as both radioprotectors and diagnostic agents distinguishes them from traditional compounds, paving the way for innovative practical applications. Their use in radiotherapy represents a significant step toward the development of safer and more effective strategies in radiation protection and cancer treatment. We also review ionizing radiation effects, classifications, cancer radiotherapy applications, and countermeasures.

Metallofullerenol Gd@C82(OH)22 preserves human erythrocyte plasma membrane integrity from AAPH-induced oxidative stress: Molecular mechanisms and antioxidant activity

Metallofullerenols and fullerenols have attracted attention due to their remarkable ability to interact with various biologically relevant molecules, paving the way for biomedical applications, ranging from medical imaging techniques to drug carriers, acting with increased efficiency and reduced side effects. In this work, we investigated the effects of two fullerene derivatives, Gd@C82(OH)22 and C70(OH)12, on erythrocyte membrane components under oxidative stress conditions induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a source of peroxyl radicals. The results demonstrated that gadolinium encapsulation within the fullerene cage enhanced the electron affinity of Gd@C82(OH)22, resulting in stronger antioxidant activity. Gd@C82(OH)22 formed a protective hydrophilic layer at the lipid-water interface, effectively preventing lipid peroxidation, oxidative protein damage, and potassium leakage, outperforming C70(OH)12. Both compounds improved membrane fluidity, but Gd@C82(OH)22 exhibited superior preservation of the erythrocyte lipid bilayer and protein function. Additionally, Gd@C82(OH)22 maintained the anion exchange function of band 3 protein, which is critical for ionic homeostasis, by preventing oxidation-induced aggregation and preserving thiol groups. Despite its limited membrane penetration, Gd@C82(OH)22 stabilized membrane components through hydrogen bonding, which indirectly enhanced membrane stiffness and fluidity under oxidative stress. This external protection of membrane integrity reduced the risk of lipid peroxidation and oxidative damage to erythrocyte proteins. In contrast, C70(OH)12, while effective in protecting membrane lipids, was less effective in preserving protein structure. These findings highlight the unique protective properties of Gd@C82(OH)22, attributed to polarization effects induced by the encapsulated Gd atom. This study indicates that metallofullerenols, such as Gd@C82(OH)22, may have therapeutic potential in mitigating oxidative damage.

Leveraging the dual role of ROS in liver diseases with nanomaterials: clearing and amplifying for therapy

The dual role of reactive oxygen species (ROS) in various liver diseases leads to the potential of nanomaterials in addressing challenges related to liver conditions. Considering the pivotal role of ROS in liver disease progression, the design and application of nanomaterials need to align with distinct disease characteristics and the unique liver microenvironment. By reviewing the interaction between nanomaterials and ROS in liver diseases and their potential applications in liver disease treatment, this work discusses the multifaceted properties of nanomaterials and their high specificity and prospects in liver disease treatments.

Fullerene Derivatives for Tumor Treatment: Mechanisms and Application

Fullerenes hold tremendous potential as alternatives to conventional chemotherapy or radiotherapy for tumor treatment due to their abilities to photodynamically kill tumor cells, destroy the tumor vasculature, inhibit tumor metastasis and activate anti-tumor immune responses, while protecting normal tissue through antioxidative effects. The symmetrical hollow molecular structures of fullerenes with abundant C=C bonds allow versatile chemical modification with diverse functional groups, metal clusters and biomacromolecules to synthesize a wide range of fullerene derivatives with increased water solubility, improved biocompatibility, enhanced photodynamic properties and stronger targeting abilities. This review introduces the anti-tumor mechanisms of fullerenes and summarizes the most recent works on the functionalization of fullerenes and the application of fullerene derivatives in tumor treatment. This review aims to serve as a valuable reference for further development and clinical application of anti-tumor fullerene derivatives.

Metallofullerenol alleviates alcoholic liver damage via ROS clearance under static magnetic and electric fields

Alcoholic liver disease (ALD) is a common chronic redox disease caused by increased alcohol consumption. Abstinence is a major challenge for people with alcohol dependence, and approved drugs have limited efficacy. Therefore, this study aimed to explore a new treatment strategy for ALD using ferroferric oxide endohedral fullerenol (Fe3O4@C60(OH)n) in combination with static magnetic and electric fields (sBE). The primary hepatocytes of 8-9-week-old female BALB/c mice were used to evaluate the efficacy of the proposed combination treatment. A mouse chronic binge ethanol feeding model was established to determine the alleviatory effect of Fe3O4@C60(OH)n on liver injury under sBE exposure. Furthermore, the ability of Fe3O4@C60(OH)n to eliminate •OH was evaluated. Alcohol-induced hepatocyte and mitochondrial damage were reversed in vitro. Additionally, the combination therapy reduced liver damage, alleviated oxidative stress by improving antioxidant levels, and effectively inhibited liver lipid accumulation in animal experiments. Here, we used a combination of magnetic derivatives of fullerenol and sBE to further improve the ROS clearance rate, thereby alleviating ALD. The developed combination treatment may effectively improve alcohol-induced liver damage and maintain redox balance without apparent toxicity, thereby enhancing therapy aimed at ALD and other redox diseases.

Versatile applications of fullerenol nanoparticles

Nanomaterials have become increasingly important over time as research technology has enabled the progressively precise study of materials at the nanoscale. Developing an understanding of how nanomaterials are produced and tuned allows scientists to utilise their unique properties for a variety of applications, many of which are already incorporated into commercial products. Fullerenol nanoparticles C60(OH)n, 2 ≤ n ≤ 44 are fullerene derivatives and are produced synthetically. They have good biocompatibility, low toxicity and no immunological reactivity. In addition, their nanometre size, large surface area to volume ratio, ability to penetrate cell membranes, adaptable surface that can be easily modified with different functional groups, drug release, high physical stability in biological media, ability to remove free radicals, magnetic and optical properties make them desirable candidates for various applications. This review comprehensively summarises the various applications of fullerenol nanoparticles in different scientific fields such as nanobiomedicine, including antibacterial and antiviral agents, and provides an overview of their use in agriculture and biosensor technology. Recommendations are also made for future research that would further elucidate the mechanisms of fullerenols actions.

Nanomaterials-based advanced systems for photothermal / photodynamic therapy of oral cancer

The traditional clinical approaches for oral cancer consist of surgery, chemotherapy, radiotherapy, immunotherapy, and so on. However, these treatments often induce side effects and exhibit limited efficacy. Photothermal therapy (PTT) emerges as a promising adjuvant treatment, utilizing photothermal agents (PTAs) to convert light energy into heat for tumor ablation. Another innovative approach, photodynamic therapy (PDT), leverages photosensitizers (PSs) and specific wavelength laser irradiation to generate reactive oxygen species (ROS), offering an effective and non-toxic alternative. The relevant combination therapies have been reported in the field of oral cancer. Simultaneously, the advancement of nanomaterials has propelled the clinical application of PTT and PDT. Therefore, a comprehensive understanding of PTT and PDT is required for better application in oral cancer treatment. Here, we review the use of PTT and PDT in oral cancer, including noble metal materials (e.g., Au nanoparticles), carbon materials (e.g., graphene oxide), organic dye molecules (e.g., indocyanine green), organic molecule-based agents (e.g., porphyrin-analog phthalocyanine) and other inorganic materials (e.g., MXenes), exemplify the advantages and disadvantages of common PTAs and PSs, and summarize the combination therapies of PTT with PDT, PTT/PDT with chemotherapy, PTT with radiotherapy, PTT/PDT with immunotherapy, and PTT/PDT with gene therapy in the treatment of oral cancer. The challenges related to the PTT/PDT combination therapy and potential solutions are also discussed.

Systematic review of the osteogenic effect of rare earth nanomaterials and the underlying mechanisms

Rare earth nanomaterials (RE NMs), which are based on rare earth elements, have emerged as remarkable biomaterials for use in bone regeneration. The effects of RE NMs on osteogenesis, such as promoting the osteogenic differentiation of mesenchymal stem cells, have been investigated. However, the contributions of the properties of RE NMs to bone regeneration and their interactions with various cell types during osteogenesis have not been reviewed. Here, we review the crucial roles of the physicochemical and biological properties of RE NMs and focus on their osteogenic mechanisms. RE NMs directly promote the proliferation, adhesion, migration, and osteogenic differentiation of mesenchymal stem cells. They also increase collagen secretion and mineralization to accelerate osteogenesis. Furthermore, RE NMs inhibit osteoclast formation and regulate the immune environment by modulating macrophages and promote angiogenesis by inducing hypoxia in endothelial cells. These effects create a microenvironment that is conducive to bone formation. This review will help researchers overcome current limitations to take full advantage of the osteogenic benefits of RE NMs and will suggest a potential approach for further osteogenesis research.

A Review on the Design of Carbon-Based Nanomaterials as MRI Contrast Agents

The administration of magnetic resonance imaging (MRI) contrast agents (CAs) has been conducted since 1988 by clinicians to enhance the clarity and interpretability of MR images. CAs based on gadolinium chelates are the clinical standard used worldwide for the diagnosis of various pathologies, such as the detection of brain lesions, the visualization of blood vessels, and the assessment of soft tissue disorders. However, due to ongoing concerns associated with the safety of gadolinium-based contrast agents, considerable efforts have been directed towards developing contrast agents with better relaxivities, reduced toxicity, and eventually combined therapeutic modalities. In this context, grafting (or encapsulating) paramagnetic metals or chelates onto (within) carbon-based nanoparticles is a straightforward approach enabling the production of contrast agents with high relaxivities while providing extensive tuneability regarding the functionalization of the nanoparticles. Here, we provide an overview of the parameters defining the efficacy of lanthanide-based contrast agents and the subsequent developments in the field of nanoparticular-based contrast agents incorporating paramagnetic species.

New insights into nanosystems for non-small-cell lung cancer: diagnosis and treatment

Lung cancer is caused by a malignant tumor that shows the fastest growth in both incidence and mortality and is also the greatest threat to human health and life. At present, both in terms of incidence and mortality, lung cancer is the first in male malignant tumors, and the second in female malignant tumors. In the past two decades, research and development of antitumor drugs worldwide have been booming, and a large number of innovative drugs have entered clinical trials and practice. In the era of precision medicine, the concept and strategy of cancer from diagnosis to treatment are experiencing unprecedented changes. The ability of tumor diagnosis and treatment has rapidly improved, the discovery rate and cure rate of early tumors have greatly improved, and the overall survival of patients has benefited significantly, with a tendency to transform to a chronic disease with tumor. The emergence of nanotechnology brings new horizons for tumor diagnosis and treatment. Nanomaterials with good biocompatibility have played an important role in tumor imaging, diagnosis, drug delivery, controlled drug release, etc. This article mainly reviews the advancements in lipid-based nanosystems, polymer-based nanosystems, and inorganic nanosystems in the diagnosis and treatment of non-small-cell lung cancer (NSCLC).

Quenching of Protein Fluorescence by Fullerenol C60(OH)36 Nanoparticles

The effect of the interaction between fullerenol C60(OH)36 (FUL) and alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae and human serum albumin (HSA) was studied by absorption spectroscopy, fluorescence spectroscopy, and time-resolved fluorescence spectroscopy. As shown in the study, the fluorescence intensities of ADH and HSA at excitation wavelengths λex = 280 nm (Trp, Tyr) and λex = 295 nm (Trp) are decreased with the increase in the FUL concentration. The results of time-resolved measurements indicate that both quenching mechanisms, dynamic and static, are present. The binding constant Kb and the number of binding sites were obtained for HSA and ADH. Thus, the results indicated the formation of FUL complexes and proteins. However, the binding of FUL to HSA is much stronger than that of ADH. The transfer of energy from the protein to FUL was also proved.

Fullerenol C60(OH)36 Protects the Antioxidant Enzymes in Human Erythrocytes against Oxidative Damage Induced by High-Energy Electrons

Ionizing radiation (IR) can pass through the human body easily, potentially causing severe damage to all biocomponents, which is associated with increasing oxidative stress. IR is employed in radiotherapy; however, in order to increase safety, it is necessary to minimize side effects through the use of radioprotectors. Water-soluble derivatives of fullerene exhibit antiradical and antioxidant properties, and these compounds are regarded as potential candidates for radioprotectors. We examined the ability of fullerenol C60(OH)36 to protect human erythrocytes, including the protection of the erythrocytal antioxidant system against high-energy electrons. Human erythrocytes irradiated with high-energy [6 MeV] electrons were treated with C60(OH)36 (150 µg/mL), incubated and haemolyzed. The radioprotective properties of fullerenol were determined by examining the antioxidant enzymes activity in the hemolysate, the concentration of -SH groups, as well as by determining erythrocyte microviscosity. The irradiation of erythrocytes (650 and 1300 Gy) reduces the number of thiol groups; however, an attenuation of this harmful effect is observed (p < 0.05) in the presence of C60(OH)36. Although no significant effect of fullerenol was recorded on catalase activity, which was preserved in both control and test samples, a more active protection of other enzymes was evident. An irradiation-induced decrease in the activity of glutathione peroxidase and glutathione reductase became an increase in the activity of those two enzymes in samples irradiated in the presence of C60(OH)36 (p < 0.05 and p < 0.05, respectively). The fourth studied enzyme, glutathione transferase, decreased (p < 0.05) its activity in the irradiated hemolysate treated with C60(OH)36, thus, indicating a lower level of ROS in the system. However, the interaction of fullerenol with the active centre of the enzyme cannot be excluded. We also noticed that radiation caused a dose-dependent decrease in the erythrocyte microviscosity, and the presence of C60(OH)36 reduced this effect (p < 0.05). Overall, we point to the radioprotective effect of C60(OH)36 manifested as the protection of the antioxidant enzymes of human erythrocytes against IR-induced damage, which has not been the subject of intense research so far.