Developing [60]Fullerene Nanomaterials for Better Photodynamic Treatment of Non-Melanoma Skin Cancers

One-pot hydrothermal synthesis of silicon, nitrogen co-doped carbon dots for enhancing enzyme activity of acid phosphatase (ACP) to dopamine and for cell imaging

Developing water-soluble nanomaterials with high photoluminescence emission and high yield for biological analysis and imaging is urgently needed. Herein, water-soluble blue emitting silicon and nitrogen co-doped carbon dots (abbreviated as Si-CDs) of a high photoluminescence quantum yield of 80 % were effectively prepared with high yield rate (59.1 %) via one-step hydrothermal treatment of N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO) and trans-aconitic acid. Furthermore, the Si-CDs demonstrate environmental robustness, photo-stability and biocompatibility. Given the importance of the potentially abnormal levels of acid phosphatase (ACP) in cancer diagnosis, developing a reliable and sensitive ACP measurement method is of significance for clinical research. The Si-CDs unexpectedly promote the catalytic oxidation of ACP on dopamine (DA) to polydopamine under acidic conditions through the produced reactive oxygen species (ROS). Correspondingly, a fluorescence response strategy using Si-CDs as the dual functions of probes and promoting enzyme activity of ACP on catalyzing DA was constructed to sensitively determine ACP. The quantitative analysis of ACP displayed a linear range of 0.1-60 U/L with a detection limit of 0.056 U/L. The accurate detection of ACP was successfully achieved in human serum through recovery tests. As a satisfactory fluorescent probe, Si-CDs were successfully applied to fluorescent imaging of A549 cells in cytoplasmic with long-term and safe staining. The Si-CDs have the dual properties of outstanding fluorescent probes and auxiliary oxidase activity, indicating their great potential in multifunctional applications.

Advances in Nanomaterials for Immunotherapeutic Improvement of Cancer Chemotherapy

Immuno-stimulative effect of chemotherapy (ISECT) is recognized as a potential alternative to conventional immunotherapies, however, the clinical application is constrained by its inefficiency. Metronomic chemotherapy, though designed to overcome these limitations, offers inconsistent results, with effectiveness varying based on cancer types, stages, and patient-specific factors. In parallel, a wealth of preclinical nanomaterials holds considerable promise for ISECT improvement by modulating the cancer-immunity cycle. In the area of biomedical nanomaterials, current literature reviews mainly concentrate on a specific category of nanomaterials and nanotechnological perspectives, while two essential issues are still lacking, i.e., a comprehensive analysis addressing the causes for ISECT inefficiency and a thorough summary elaborating the nanomaterials for ISECT improvement. This review thus aims to fill these gaps and catalyze further development in this field. For the first time, this review comprehensively discusses the causes of ISECT inefficiency. It then meticulously categorizes six types of nanomaterials for improving ISECT. Subsequently, practical strategies are further proposed for addressing inefficient ISECT, along with a detailed discussion on exemplary nanomedicines. Finally, this review provides insights into the challenges and perspectives for improving chemo-immunotherapy by innovations in nanomaterials.

Comparative Studies of the Structural and Physicochemical Properties of the First Fullerene Derivative FD-C60 (Fullerenol) and Second Fullerene Derivate SD-C60 (3HFWC)

In order to maximally reduce the toxicity of fullerenol (the first derivative of C60, FD-C60), and increase its biomedical efficiency, the second derivative SD-C60 (3HFWC, Hyper-Harmonized Hydroxylated Fullerene Water Complex) was created. Several different methods were applied in the comparative characterization of FD-C60 and SD-C60 with the same OH groups in their core. FD-C60 as an individual structure was about 1.3 nm in size, while SD-C60 as an individual structure was 10-30 nm in size. Based on ten physicochemical methods and techniques, FD-C60 and SD-C60 were found to be two different substances in terms of size, structure, and physicochemical properties; FD-C60, at 100 °C, had endothermic characteristics, while SD-C60, at 133 °C, had exothermic characteristics; FD-C60 did not have water layers, while SD-C60 had water layers; the zeta potential of FD-C60 was -25.85 mV, while it was -43.29 mV for SD-C60. SD-C60 is a promising substance for use in cosmetics and pharmaceuticals.

Putting a "C60 Ball" and Chain to Chlorin e6 Improves Its Cellular Uptake and Photodynamic Performances

Chlorin e6 (Ce6) and fullerene (C60) are among the most used photosensitizers (PSs) for photodynamic therapy (PDT). Through the combination of the chemical and photophysical properties of Ce6 and C60, in principle, we can obtain an "ideal" photosensitizer that is able to bypass the limitations of the two molecules alone, i.e., the low cellular uptake of Ce6 and the scarce solubility and absorption in the red region of the C60. Here, we synthesized and characterized a Ce6-C60 dyad. The UV-Vis spectrum of the dyad showed the typical absorption bands of both fullerene and Ce6, while a quenching of Ce6 fluorescence was observed. This behavior is typical in the formation of a fullerene-antenna system and is due to the intramolecular energy, or electron transfer from the antenna (Ce6) to the fullerene. Consequently, the Ce6-C60 dyad showed an enhancement in the generation of reactive oxygen species (ROS). Flow cytometry measurements demonstrated how the uptake of the Ce6 was strongly improved by the conjugation with C60. The Ce6-C60 dyad exhibited in A431 cancer cells low dark toxicity and a higher PDT efficacy than Ce6 alone, due to the enhancement of the uptake and the improvement of ROS generation.

Uncovering nanotoxicity of a water-soluble and red-fluorescent [70]fullerene nanomaterial

Engineered fullerene materials have attracted the attention of researchers in the biomedical sciences, especially when their synthetic methodology is developed to endow them with significant levels of water-solubility and bioavailability. In this study, we synthesized and characterized a water-soluble and red-fluorescent [70]fullerene nanomaterial, which fluoresced at 693 nm with a quantum yield of 0.065 and a large Stokes shift (around 300 nm). The fullerene nanomaterial generated mainly singlet oxygen after illumination with blue LED light, while superoxide anion radical production was minimal. The transmission electron microscopy as well as fluorescent studies of Drosophila melanogaster revealed that prepared [70]fullerene nanoparticles had better bioavailability than pristine [70]fullerene nanoparticles. The designed nanomaterials were observed in the apical, perinuclear, and basal regions of digestive cells, as well as the basal lamina of the digestive system's epithelium, with no damage to cell organelles and no activation of degenerative processes and cell death. Our findings provide a new perspective for understanding the in vivo behavior of fullerene nanomaterials and their future application in bioimaging and light-activated nanotherapeutics.

Enhancing Skin Cancer Immunotheranostics and Precision Medicine through Functionalized Nanomodulators and Nanosensors: Recent Development and Prospects

Skin cancers, especially melanomas, present a formidable diagnostic and therapeutic challenge to the scientific community. Currently, the incidence of melanomas shows a high increase worldwide. Traditional therapeutics are limited to stalling or reversing malignant proliferation, increased metastasis, or rapid recurrence. Nonetheless, the advent of immunotherapy has led to a paradigm shift in treating skin cancers. Many state-of-art immunotherapeutic techniques, namely, active vaccination, chimeric antigen receptors, adoptive T-cell transfer, and immune checkpoint blockers, have achieved a considerable increase in survival rates. Despite its promising outcomes, current immunotherapy is still limited in its efficacy. Newer modalities are now being explored, and significant progress is made by integrating cancer immunotherapy with modular nanotechnology platforms to enhance its therapeutic efficacy and diagnostics. Research on targeting skin cancers with nanomaterial-based techniques has been much more recent than other cancers. Current investigations using nanomaterial-mediated targeting of nonmelanoma and melanoma cancers are directed at augmenting drug delivery and immunomodulation of skin cancers to induce a robust anticancer response and minimize toxic effects. Many novel nanomaterial formulations are being discovered, and clinical trials are underway to explore their efficacy in targeting skin cancers through functionalization or drug encapsulation. The focus of this review rivets on theranostic nanomaterials that can modulate immune mechanisms toward protective, therapeutic, or diagnostic approaches for skin cancers. The recent breakthroughs in nanomaterial-based immunotherapeutic modulation of skin cancer types and diagnostic potentials in personalized immunotherapies are discussed.

Enhanced Uptake and Phototoxicity of C60@albumin Hybrids by Folate Bioconjugation

Fullerenes are considered excellent photosensitizers, being highly suitable for photodynamic therapy (PDT). A lack of water solubility and low biocompatibility are, in many instances, still hampering the full exploitation of their potential in nanomedicine. Here, we used human serum albumin (HSA) to disperse fullerenes by binding up to five fullerene cages inside the hydrophobic cavities. Albumin was bioconjugated with folic acid to specifically address the folate receptors that are usually overexpressed in several solid tumors. Concurrently, tetramethylrhodamine isothiocyanate, TRITC, a tag for imaging, was conjugated to C₆₀@HSA in order to build an effective phototheranostic platform. The in vitro experiments demonstrated that: (i) HSA disperses C₆₀ molecules in a physiological environment, (ii) HSA, upon C₆₀ binding, maintains its biological identity and biocompatibility, (iii) the C₆₀@HSA complex shows a significant visible-light-induced production of reactive oxygen species, and (iv) folate bioconjugation improves both the internalization and the PDT-induced phototoxicity of the C₆₀@HSA complex in HeLa cells.

Controlled Decoration of [60]Fullerene with Polymannan Analogues and Amino Acid Derivatives through Malondiamide-Based Linkers

In the last few years, nanomaterials based on fullerene have begun to be considered promising tools in the development of efficient adjuvant/delivery systems for vaccination, thanks to their several advantages such as biocompatibility, size, and easy preparation and modification. In this work we reported the chemoenzymatic synthesis of natural polymannan analogues (di- and tri-mannan oligosaccharides characterized by α1,6man and/or α1,2man motifs) endowed with an anomeric propargyl group. These sugar derivatives were submitted to 1,3 Huisgen dipolar cycloaddition with a malondiamide-based chain equipped with two azido terminal groups. The obtained sugar-modified malondiamide derivatives were used to functionalize the surface of Buckminster fullerene (C₆₀) in a highly controlled fashion, and yields (11–41%) higher than those so far reported by employing analogue linkers. The same strategy has been exploited to obtain C₆₀ endowed with natural and unnatural amino acid derivatives. Finally, the first double functionalization of fullerene with both sugar- and amino acid-modified malondiamide chains was successfully performed, paving the way to the possible derivatization of fullerenes with immunogenic sugars and more complex antigenic peptides.

Combined Action of Hyper-Harmonized Hydroxylated Fullerene Water Complex and Hyperpolarized Light Leads to Melanoma Cell Reprogramming In Vitro

(1) Background: Their unique structure and electron deficiency have brought fullerenes into the focus of research in many fields, including medicine. The hyper-harmonized hydroxylated fullerene water complex (3HFWC) formulation has solved the limitations of the poor solubility and bioavailability of fullerenes. To achieve better antitumor activity, 3HFWC was combined with short-term irradiation of cells with hyperpolarized light (HPL) generated by the application of a nanophotonic fullerene filter in a Bioptron^® device. The benefits of HPL were confirmed in the microcirculation, wound healing and immunological function. (2) Methods: B16, B16-F10 and A375 melanoma cells were exposed to a wide spectrum of 3HFWC doses and to a single short-term HPL irradiation. (3) Results: Apart from the differences in the redox status and level of invasiveness, the effects of the treatments were quite similar. Decreased viability, morphological alteration, signs of melanocytic differentiation and cellular senescence were observed upon the successful internalization of the nanoquantum substance. (4) Conclusions: Overall, 3HFWC/HPL promoted melanoma cell reprogramming toward a normal phenotype.

Application of nanotechnology in the diagnosis and treatment of acute pancreatitis

Acute pancreatitis (AP) is a common digestive system disease. The severity of AP ranges from mild edema in the pancreas to severe systemic inflammatory responses leading to peripancreatic/pancreatic necrosis, multi-organ failure and death. Improving the sensitivity of AP diagnosis and developing alternatives to traditional methods to treat AP have gained the attention of researchers. With the continuous rise of nanotechnology, it is being widely used in daily life, biomedicine, chemical energy and many other fields. Studies have demonstrated the effectiveness of nanotechnology in the diagnosis and treatment of AP. Nanotechnology has the advantages of simplicity, rapidity and sensitivity in detecting biomarkers of AP, as well as enhancing imaging, which helps in the early diagnosis of AP. On the other hand, nanoparticles (NPs) have oxidative stress inhibiting and anti-inflammatory effects, and can also be loaded with drugs as well as being used in anti-infection therapy, providing a new approach for the treatment of AP. In this article, we elaborate and summarize on the potential of nanoparticles for diagnostic and therapeutic applications in AP from the current reported literature and experimental results to provide useful guidelines for further research on the application of nanotechnology.

Alkali metal decorated C60 fullerenes as promising materials for delivery of the 5-fluorouracil anticancer drug: a DFT approach

The development of effective drug delivery vehicles is essential for the targeted administration and/or controlled release of drugs. Using first-principles calculations, the potential of alkali metal (AM = Li, Na, and K) decorated C₆₀ fullerenes for delivery of 5-fluorouracil (5FU) is explored. The adsorption energies of the 5FU on a single AM atom decorated C₆₀ are −19.33, −16.58, and −14.07 kcal mol⁻¹ for AM = Li, Na, and K, respectively. The results, on the other hand, show that up to 12 Li and 6 Na or K atoms can be anchored on the exterior surface of the C₆₀ fullerene simultaneously, each of which can interact with a 5FU molecule. Because of the moderate adsorption energies and charge-transfer values, the 5FU can be simply separated from the fullerene at ambient temperature. Furthermore, the results show that the 5FU may be easily protonated in the target cancerous tissues, which facilitates the release of the drug from the fullerene. The inclusion of solvent effects tends to decrease the 5FU adsorption energies in all 5FU-fullerene complexes. This is the first report on the high capability of AM decorated fullerenes for delivery of multiple 5FU molecules utilizing a C₆₀ host molecule.

DFT calculations show the capability of alkali metal (AM = Li, Na, and K) decorated C60 fullerenes to deliver multiple 5-fluorouracil 5FU molecules. The results show 5FU may be protonated to target cancerous tissues, this causes the drug to be realised from the fullerene.

Dissecting the Supramolecular Dispersion of Fullerenes by Proteins/Peptides: Amino Acid Ranking and Driving Forces for Binding to C60

Molecular dynamics simulations were used to quantitatively investigate the interactions between the twenty proteinogenic amino acids and C₆₀. The conserved amino acid backbone gave a constant energetic interaction ~5.4 kcal mol⁻¹, while the contribution to the binding due to the amino acid side chains was found to be up to ~5 kcal mol⁻¹ for tryptophan but lower, to a point where it was slightly destabilizing, for glutamic acid. The effects of the interplay between van der Waals, hydrophobic, and polar solvation interactions on the various aspects of the binding of the amino acids, which were grouped as aromatic, charged, polar and hydrophobic, are discussed. Although π–π interactions were dominant, surfactant-like and hydrophobic effects were also observed. In the molecular dynamics simulations, the interacting residues displayed a tendency to visit configurations (i.e., regions of the Ramachandran plot) that were absent when C₆₀ was not present. The amino acid backbone assumed a “tepee-like” geometrical structure to maximize interactions with the fullerene cage. Well-defined conformations of the most interactive amino acids (Trp, Arg, Met) side chains were identified upon C₆₀ binding.

Towards water-soluble [60]fullerenes for the delivery of siRNA in a prostate cancer model

This paper presents two water-soluble fullerene nanomaterials (HexakisaminoC₆₀ and monoglucosamineC₆₀, which is called here JK39) that were developed and synthesized as non-viral siRNA transfection nanosystems. The developed two-step Bingel-Hirsch reaction enables the chemical modification of the fullerene scaffold with the desired bioactive fragments such as D-glucosamine while keeping the crucial positive charged ethylenediamine based malonate. The ESI-MS and ¹³C-NMR analyses of JK39 confirmed its high T_h symmetry, while X-ray photoelectron spectroscopy revealed the presence of nitrogen and oxygen-containing C-O or C-N bonds. The efficiency of both fullerenes as siRNA vehicles was tested in vitro using the prostate cancer cell line DU145 expressing the GFP protein. The HexakisaminoC₆₀ fullerene was an efficient siRNA transfection agent, and decreased the GFP fluorescence signal significantly in the DU145 cells. Surprisingly, the glycofullerene JK39 was inactive in the transfection experiments, probably due to its high zeta potential and the formation of an extremely stable complex with siRNA.

Photodynamic Therapy—An Up-to-Date Review

The healing power of light has attracted interest for thousands of years. Scientific discoveries and technological advancements in the field have eventually led to the emergence of photodynamic therapy, which soon became a promising approach in treating a broad range of diseases. Based on the interaction between light, molecular oxygen, and various photosensitizers, photodynamic therapy represents a non-invasive, non-toxic, repeatable procedure for tumor treatment, wound healing, and pathogens inactivation. However, classic photosensitizing compounds impose limitations on their clinical applications. Aiming to overcome these drawbacks, nanotechnology came as a solution for improving targeting efficiency, release control, and solubility of traditional photosensitizers. This paper proposes a comprehensive path, starting with the photodynamic therapy mechanism, evolution over the years, integration of nanotechnology, and ending with a detailed review of the most important applications of this therapeutic approach.

Efficacy, biocompatibility and degradability of carbon nanoparticles for photothermal therapy of lung cancer

Aim: To investigate near infrared-induced phototoxicity toward lung cancer cells, and the biodegradability and effect on immune cells of glucose-derived carbon nanoparticles (CNPs). Methods: The human A549 lung adenocarcinoma cell line was used as a model to study the phototoxicity of CNPs. The biodegradability and the effect on immune cells was demonstrated in primary human neutrophils and macrophages. Results: Near infrared-activated CNPs elicited rapid cell death, characterized by the elevation of heat shock proteins and the induction of DNA damage. CNPs were found to be noncytotoxic toward primary human macrophages and were susceptible to biodegradation when cocultured with human neutrophils. Conclusions: Our results identify CNPs as promising platforms for photothermal therapy of lung cancer.

Green Approaches to Carbon Nanostructure-Based Biomaterials

The family of carbon nanostructures comprises several members, such as fullerenes, nano-onions, nanodots, nanodiamonds, nanohorns, nanotubes, and graphene-based materials. Their unique electronic properties have attracted great interest for their highly innovative potential in nanomedicine. However, their hydrophobic nature often requires organic solvents for their dispersibility and processing. In this review, we describe the green approaches that have been developed to produce and functionalize carbon nanomaterials for biomedical applications, with a special focus on the very latest reports.

Interactions of a Water-Soluble Glycofullerene with Glucose Transporter 1. Analysis of the Cellular Effects on a Pancreatic Tumor Model

In recent years, carbon nanomaterials have been intensively investigated for their possible applications in biomedical studies, especially as drug delivery vehicles. Several surface modifications can modulate the unique molecular structure of [60]fullerene derivatives, as well as their physicochemical properties. For this reason, covalent modifications that would enable a greater water solubilization of the fullerene buckyball have been rapidly investigated. The most exciting applications of fullerene nanomaterials are as drug delivery vectors, photosensitizers in photodynamic therapy (PDT), astransfection or MRI contrast agents, antimicrobials and antioxidants. From these perspectives, the glucose derivatives of [60]fullerene seem to be an interesting carbon nanomaterial for biological studies. It is well-known that cancer cells are characterized by an increased glucose uptake and it has also been previously reported that the glucose transporters (GLUTs) are overexpressed in several types of cancers, which make them attractive molecular targets for many drugs. This study explored the use of a highly water-soluble glycofullerene (called Sweet-C₆₀) in pancreatic cancer studies. Here, we describe the PANC-1 cell proliferation, migration, metabolic activity and glycolysis rate after incubations with different concentrations of Sweet-C₆₀. The final results did not show any influence of the Sweet-C₆₀ on various cancer cellular events and glycolysis, suggesting that synthesized glycofullerene is a promising drug delivery vehicle for treating pancreatic cancer.