The pharmaceutical multi-activity of metallofullerenol invigorates cancer therapy

Effects of Endohedral Gd-Containing Fullerenols with a Different Number of Oxygen Substituents on Bacterial Bioluminescence

Gadolinium (Gd)-containing fullerenols are perspective agents for magnetic resonance imaging and cancer research. They combine the unique paramagnetic properties of Gd with solubility in water, low toxicity and antiradical activity of fullerenols. We compared the bioeffects of two Gd-containing fullerenols with a different number of oxygen groups-20 and 42: Gd@C82O20H14 and Gd@C82O42H32. The bioluminescent bacteria-based assay was applied to monitor the toxicity of fullerenols, bioluminescence was applied as a signal physiological parameter, and bacterial enzyme-based assay was used to evaluate the fullerenol effects on enzymatic intracellular processes. Chemiluminescence luminol assay was applied to monitor the content of reactive oxygen species (ROS) in bacterial and enzymatic media. It was shown that Gd@C82O42H32 and Gd@C82O20H14 inhibited bacterial bioluminescence at >10-1 and >10-2 gL-1, respectively, revealing a lower toxicity of Gd@C82O42H32. Low-concentration (10-3-10-1 gL-1) bacterial bioluminescence activation by Gd@C82O42H32 was observed, while this activation was not found under exposure to Gd@C82O20H14. Additional carboxyl groups in the structure of Gd@C82O42H32 were determined by infrared spectroscopy and confirmed by quantum chemical calculations. The groups were supposed to endow Gd@C82O42H32 with higher penetration ability through the cellular membrane, activation ability, lower toxicity, balancing of the ROS content in the bacterial suspensions, and lower aggregation in aqueous media.

Advances of nanotechnology applied to cancer stem cells

Cancer stem cells (CSCs) are a small proportion of the cells that exist in cancer tissues. They are considered to be the culprit of tumor genesis, development, drug resistance, metastasis and recurrence because of their self-renewal, proliferation, and differentiation potential. The elimination of CSCs is thus the key to cure cancer, and targeting CSCs provides a new method for tumor treatment. Due to the advantages of controlled sustained release, targeting and high biocompatibility, a variety of nanomaterials are used in the diagnosis and treatments targeting CSCs and promote the recognition and removal of tumor cells and CSCs. This article mainly reviews the research progress of nanotechnology in sorting CSCs and nanodrug delivery systems targeting CSCs. Furthermore, we identify the problems and future research directions of nanotechnology in CSC therapy. We hope that this review will provide guidance for the design of nanotechnology as a drug carrier so that it can be used in clinic for cancer therapy as soon as possible.

Metallofullerenols in biomedical applications

Metallofullerenols (MFs) are functionalized endohedral fullerenes connecting at least three levels of organization of matter: atomic, molecular, and supramolecular, resulting in their unique activity at the nanoscale. Biomedical applications of MFs started from gadolinium-containing contrasting agents, but today their potential medical applications go far beyond diagnostics and magnetic resonance imaging. In many cases, preclinical studies have shown a great therapeutic value of MFs, and here we provide an overview of interactions of MFs with high-energy radiation and with reactive oxygen species generated during radiation as a ground for potential applications in modern therapy of cancer patients. We also present the current knowledge on interactions of MFs with proteins and with other components of cells and tissues. Due to their antioxidant properties, as well as their ability to regulate the expression of genes involved in apoptosis, angiogenesis, and stimulation of the immune response, MFs can contribute to inhibition of tumor growth and protection of normal cells. MFs with enclosed gadolinium act as inhibitors of tumor growth in targeted therapy along with imaging techniques, but we hope that the data gathered in this review will help to accelerate further progress in the implementation of MFs, also the ones containing rare earth metals other than gadolinium, in a broad range of bioapplications covering not only diagnostics and bioimaging but also radiation therapy and cancer treatment by not-cytotoxic agents.

Emerging Nanotherapeutic Approaches to Overcome Drug Resistance in Cancers with Update on Clinical Trials

A key issue with modern cancer treatments is the emergence of resistance to conventional chemotherapy and molecularly targeted medicines. Cancer nanotherapeutics were created in order to overcome the inherent limitations of traditional chemotherapeutics. Over the last few decades, cancer nanotherapeutics provided unparalleled opportunities to understand and overcome drug resistance through clinical assessment of rationally designed nanoparticulate delivery systems. In this context, various design strategies such as passive targeting, active targeting, nano-drug, and multimodal nano-drug combination therapy provided effective cancer treatment. Even though cancer nanotherapy has made great technological progress, tumor biology complexity and heterogeneity and a lack of comprehensive knowledge of nano-bio interactions remain important roadblocks to future clinical translation and commercialization. The current developments and advancements in cancer nanotherapeutics employing a wide variety of nanomaterial-based platforms to overcome cancer treatment resistance are discussed in this article. There is also a review of various nanotherapeutics-based approaches to cancer therapy, including targeting strategies for the tumor microenvironment and its components, advanced delivery systems for specific targeting of cancer stem cells (CSC), as well as exosomes for delivery strategies, and an update on clinical trials. Finally, challenges and the future perspective of the cancer nanotherapeutics to reverse cancer drug resistance are discussed.

Potential Resistance to Antineoplastic Aminated Fullerenes Mediated by M2-Like Monocyte-Derived Exosomes

Exosomes are small extracellular vesicles critical for intercellular signaling via their delivery of cargoes, including proteins, DNA, RNA, lipids, and metabolites. Exosomes play essential roles in remodeling the tumor microenvironment (TME) for tumor growth, metastasis, and drug resistance. Aminated fullerenes (e.g., C₇₀-ethylenediamine [EDA]) exhibit antineoplastic effects by targeting multiple functional proteins. Nanosized C₇₀-EDA with positive surface charges tends to be taken up by monocytes in the bloodstream and monocyte-derived macrophages in the TME. Herein, the alterations of monocytes and monocyte-derived exosomes by C₇₀-EDA have been investigated. C₇₀-EDA reprogramed THP-1 monocyte to an M2-like state and substantially increased the protein content in exosomes secreted by M2-like monocytes. Notably, C₇₀-EDA-induced M2-like monocytes released exosomes that triggered the proliferation of recipient tumor cells, which may alleviate the antineoplastic efficacy of C₇₀-EDA. As revealed by proteomic profiling of exosomes, this outcome is probably a result of Rho GTPase/p21-activated kinase (PAK) pathway activation in recipient tumor cells induced by upregulated exosomal proteins. This work indicates a promising strategy in which aminated fullerenes can be combined with PAK inhibitors for cancer therapy.

Successive Diels-Alder Cycloadditions of Cyclopentadiene to [10]CPP⊃C60: A Computational Study

Fullerenes have potential applications in many fields. To reach their full potential, fullerenes have to be functionalized. One of the most common reactions used to functionalize fullerenes is the Diels–Alder cycloaddition. In this case, it is important to control the regioselectivity of the cycloaddition during the formation of higher adducts. In C₆₀, successive Diels–Alder cycloadditions lead to the T_h-symmetric hexakisadduct. In this work, we explore computationally using density functional theory (DFT) how the presence of a [10]cycloparaphenylene ring encapsulating C₆₀ ([10]CPP⊃C₆₀) affects the regioselectivity of multiple additions to C₆₀. Our results show that the presence of the [10]CPP ring changes the preferred sites of cycloaddition compared to free C₆₀ and leads to the formation of the tetrakisadduct. Somewhat surprisingly, our calculations predict formation of this particular tetrakisadduct to be more favored in [10]CPP⊃C₆₀ than in free C₆₀.

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

Carbon nanomaterials (CNMs) and enzymes differ significantly in terms of their physico-chemical properties—their handling and characterization require very different specialized skills. Therefore, their combination is not trivial. Numerous studies exist at the interface between these two components—especially in the area of sensing—but also involving biofuel cells, biocatalysis, and even biomedical applications including innovative therapeutic approaches and theranostics. Finally, enzymes that are capable of biodegrading CNMs have been identified, and they may play an important role in controlling the environmental fate of these structures after their use. CNMs’ widespread use has created more and more opportunities for their entry into the environment, and thus it becomes increasingly important to understand how to biodegrade them. In this concise review, we will cover the progress made in the last five years on this exciting topic, focusing on the applications, and concluding with future perspectives on research combining carbon nanomaterials and enzymes.

Nanotherapeutic approach to tackle chemotherapeutic resistance of cancer stem cells

Estimates indicate that cancer will become the leading cause of mortality worldwide in the future. Tumorigenesis is a complex process that involves self-sufficiency in signs of growth, insensitivity to anti-growth signals, prevention of apoptosis, unlimited replication, sustained angiogenesis, tissue invasion, and metastasis. Cancer stem cells (CSCs) have an important role in tumor development and resistance. Here we will approach phenotypic plasticity capacity, highly efficient DNA repair systems, anti-apoptotic machinery, sustained stemness features, interaction with the tumor microenvironment, and Notch, Wnt, and Hedgehog signaling pathways. The researches about CSCs as a target in cancer treatment has been growing. Many different options have pointed beneficial results, such as pathways and CSC-surface markers targeting. Besides its limitations, nanotherapeutics have emerged as a potential strategy in this context since they aim to improve pharmacokinetics, biodistribution, and reduce the side effects observed in traditional treatments. Nanoparticles have been studied in this field, mostly for drug delivery and a multitherapy approach. Another widely researched approaches in this area are related to heat therapy, such as photothermal therapy, photodynamic therapy and magnetic hyperthermia, besides molecular targeting. This review will contemplate the most relevant studies that have shown the effects of nanotherapeutics. In conclusion, although the studies analyzed are mostly preclinical, we believe that there is strong evidence that nanoparticles can increase the chances of a better prognosis to cancer in the future. It is also essential to transpose these findings to the clinic to confirm and better understand the role of nanotherapeutics in this context.

Cellular Uptake, Organelle Enrichment, and In Vitro Antioxidation of Fullerene Derivatives, Mediated by Surface Charge

Hydrophilic fullerene derivatives get notable performance in various biological applications, especially in cancer therapy and antioxidation. The biological behaviors of functional fullerenes are much dependent on their surface physicochemical properties. The excellent reactive oxygen species-scavenging capabilities of functional fullerenes promote their outstanding performances in inhibiting pathological symptoms associated with oxidative stress, including neurodegenerative diseases, cardiovascular diseases, acute and chronic kidney disease, and diabetes. Herein, fullerene derivatives with reversed surface charges in aqueous solutions are prepared: cationic C₆₀-EDA and anionic C₆₀-(EDA-EA). Under the driving force of membrane potential (negative inside) in the cell and mitochondria, C₆₀-EDA is much rapidly taken in by cells and transported into mitochondria compared with C₆₀-(EDA-EA) that is enriched in lysosomes. With high cellular uptake and mitochondrial enrichment, C₆₀-EDA exhibits stronger antioxidation capabilities in vitro than C₆₀-(EDA-EA), indicating its better performance in the therapy of oxidation-induced diseases. It is revealed that the cellular uptake rate, subcellular location, and intracellular antioxidation behavior of fullerene derivatives are primarily mediated by their surface charges, providing new strategies for the design of fullerene drugs and their biological applications.

Catalytic Nanomaterials toward Atomic Levels for Biomedical Applications: From Metal Clusters to Single-Atom Catalysts

Single-atom catalysts (SACs) featuring the complete atomic utilization of metal, high-efficient catalytic activity, superior selectivity, and excellent stability have been emerged as a frontier in the catalytic field. Recently, increasing interests have been drawn to apply SACs in biomedical fields for enzyme-mimic catalysis and disease therapy. To fulfill the demand of precision and personalized medicine, precisely engineering the structure and active site toward atomic levels is a trend for nanomedicines, promoting the evolution of metal-based biomedical nanomaterials, particularly biocatalytic nanomaterials, from nanoparticles to clusters and now to SACs. This review outlines the syntheses, characterizations, and catalytic mechanisms of metal clusters and SACs, with a focus on their biomedical applications including biosensing, antibacterial therapy, and cancer therapy, as well as an emphasis on their in vivo biological safeties. Challenges and future perspectives are ultimately prospected for SACs in diverse biomedical applications.

Functional gadolinium-based nanoscale systems for cancer theranostics

Cancer theranostics is a new strategy for combating cancer that integrates cancer imaging and treatment through theranostic agents to provide an efficient and safe way to improve cancer prognosis. Design and synthesis of these cancer theranostic agents are crucial since these agents are required to be biocompatible, tumor-specific, imaging distinguishable and therapeutically efficacious. In this regard, several types of gadolinium (Gd)-based nanomaterials have been introduced to combine different therapeutic agents with Gd to enhance the efficacy of therapeutic agents. At the same time, the entire treatment procedure could be monitored via imaging tools due to incorporation of Gd ions, Gd chelates and Gd/other imaging probes in the theranostic agents. This review aims to overview recent advances in the Gd-based nanomaterials for cancer theranostics and perspectives for Gd nanomaterial-based cancer theranostics are provided.

Fullerene nanoparticles: a promising candidate for the alleviation of silicosis-associated pulmonary inflammation

Chronic exposure to crystalline silica causes the development of silicosis, which is one of the most important occupational diseases worldwide. In the early stage of silicosis, inhaled silica crystals initiate oxidative stress, a cycle of persistent inflammation and lung injury. And it is crucial to prevent the deteriorative progression in the onset of the disease. Herein, we present a promising candidate for the treatment of crystalline silica-induced pulmonary inflammation, using a silicosis mouse model caused by intratracheal instillation based on local administration of β-alanine and hydroxyl functionalized C70 fullerene nanoparticles (FNs). The results demonstrate that FNs could significantly alleviate inflammatory cells infiltration, lower the secretion of pro-inflammatory cytokines, and reduce the destruction of lung architecture stimulated by crystalline silica. Further investigations reveal that FNs could effectively inhibit the activation of NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome, and thus prevent the secretion of mature IL-1β and neutrophil influx, deriving from the superior ROS scavenging capability. Importantly, FNs could not cause any obvious toxicity after pulmonary administration.

Preparation and characterisation of tetrandrine nanosuspensions and in vitro estimate antitumour activity on A549 lung cancer cell line

Aim: The aim of this study was to improve solubility and antitumour ability in vitro of tetrandrine (Tet) via preparing nanosuspensions (NSs).Methods: The Tet-NSs were prepared by wet media milling. The Tet-CCS-NS was prepared with croscarmellose sodium (CCS) as single stabiliser. The Tet-HACC-TPGS-NS was manufactured with D-α-tocopheryl polyethylene glycol 1,000 succinate (TPGS) and hydroponically trimethyl ammonium chloride chitosan (HACC) as combined stabilisers. Physicochemical properties of the NSs such as particle size, surface morphologies, crystallinity and molecular interactions were investigated. In addition, the in vitro dissolution and antitumour activities using A549 human lung cancer cells were evaluated.Results: The mean particle sizes and Zeta potential of freshly prepared Tet-CCS-NS, Tet-HACC-TPGS-NS were 469.1 ± 14nm and 157.3 ± 5nm, -29.4 ± 0.26 mV and 23.3 ± 0.36 mV, respectively. In comparison to pure Tet, the cumulative dissolution of Tet-NSs were increased by 4 ∼ 5 times in 2 h. In vitro antitumour studies on Tet- NSs in A549 cells, the cell survival rate of the Tet-NSs at high concentration (30-50µg/ml) were less than 10% within 48 h. Meanwhile, Tet-NSs were revealed to induce A549 cells apoptosis and promote cell uptake.Conclusion: The present study has proved that the Tet-NSs can increase Tet solubility as well as improve Tet antitumour activity in vitro.