Fullerene (C60 & C70)-Meso-Tris-4-Carboxyphenyl Porphyrin Dyads Inhibit Entry of Wild-Type and Drug-Resistant HIV-1 Clades B and C

The biological applications of noncationic porphyrin-fullerene (P-F) dyads as anti-HIV agents have been limited despite the established use of several cationic P-F dyads as anti-cancer photodynamic therapy (PDT) agents. This article explores the potential of amphiphilic non-cationic porphyrin-fullerene dyads as HIV-1 inhibitors under both PDT (light-treated) and non-PDT (dark) conditions. The amphiphilic P-F dyads, PB3C60 and PB3C70, demonstrated enhanced efficacy in inhibiting the entry and production of HIV-1 (subtypes B and C). Under light-harvested conditions, the dyads exhibited potent inhibitory effects (EC50 for PB3C60 and PB3C70 < 10 nM) and also maintained significant inhibition under non-PDT conditions (EC50 for PB3C60 = 1.43 μM and PB3C70 = 1.50 μM), while displaying notably reduced toxicity compared to their water-soluble porphyrin precursor. The P-F dyads exhibited substantial efficacy in neutralizing the T20-resistant strain 9491, both at the entry and postentry phases, thereby addressing the challenge of drug resistance.

Pioneering the Photoactive Relevance of Quinazolinone-Fullereropyrrolidine Nanohybrids To Address Chemotherapeutic Resistance in Cancer

This study investigates the impact of C70 and C60 fullerenes on quinazolinone, specifically in quinazolinone-fulleropyrrolidine nanohybrids. The nanohybrids Q 3 C 70 M and Q 3 C 60 M exhibit distinct spectral shifts and have significant photobiological antineoplastic properties. Q 3 C 60 M enhances apoptosis, while Q 3 C 70 M reduces Cyclin A levels and counteracts oncogenic effects by promoting cell differentiation. Q 3 C 70 M demonstrates heightened cytotoxicity by overcoming chemotherapy resistance by modulating BAX and BCL-2 levels. This innovative approach, distinguishing between C70 and C60, represents a novel contribution to the existing scientific literature.

Developing Hypoxia-Sensitive System via Designing Tumor-Targeted Fullerene-Based Photosensitizer for Multimodal Therapy of Deep Tumor

Photodynamic therapy (PDT) has been approved for clinic. However, powerless efficiency for deep hypoxic tumor therapy remains an enormous challenge for PDT. Herein, a hypoxia-sensitive nanotherapeutic system (FTCD-SRGD) based on fullerene (C70 ) and anoxic activating chemical prodrug tirapazamine (TPZ) is rationally designed for multimodal therapy of deep hypoxic tumors. To enhance the accumulation and achieve specific drug release in tumor, the FTCD-SRGD is modified with cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGDfK) peptide and disulfide bonds. With the exacerbated hypoxic microenvironment created by C70 consuming O2 for generating reactive oxygen species (ROS), TPZ is activated to produce toxic radical species to ablate deep tumors, which achieves a synergistic treatment of C70 -mediated PDT and hypoxia-enhanced chemotherapy. Additionally, given this hypoxia-sensitive system-induced immunogenic cell death (ICD) activating anticancer cytotoxic T lymphocyte to result in more susceptible tumor to immunotherapy, FTCD-SRGD plus immune checkpoint inhibitor (anti-PD-L1) fully inhibit deep hypoxic tumors by promoting infiltration of effector T cells in tumors. Collectively, it is the first time to develop a multimodal therapy system with fullerene-based hypoxia-sensitive PS for deep tumors. The powerful multimodal nanotherapeutic system for combining hypoxia-enhanced PDT and immunotherapy to massacre deep hypoxic tumors can provide a paradigm to combat the present bottleneck of tumor therapy.

Water-Soluble Fullerene Monoderivatives for Biomedical Applications

Monoderivatives of fullerenes functionalized with hydrophilic groups make them water soluble, while preserving the hydrophobic fullerene cage. This class of molecules have intriguing biomedical applications, including drug delivery, photodynamic therapy (PDT), antiviral and antimicrobial activity and reactive oxygen species (ROS)-scavenging abilities. In this Concept we discuss the synthesis and biomedical applications of water-soluble fullerene monoderivatives and their biological behavior based on their structures.

Formulation and In-Vitro Characterisation of Cross-Linked Amphiphilic Guar Gum Nanocarriers for Percutaneous Delivery of Arbutin

Nano-colloidal systems formulated from amphiphilically-modified polysaccharides (degree of modification 16.6%) are focus of prominent study due to their potential to augment active penetration across the skin. Here we report the synthesis of amphiphilically-modified guar gum (GBE-GG) prepared by grafting with glycidol butyl ether (GBE), which were subsequently formed into nanocarriers and loaded with α-arbutin (22.3% loading). The monodispersed and close-to-spherical nanocarriers (size range 239-297 nm) formed via cross-linking were adequately stable mainly at low temperature (4 °C) under physiological pH condition. α-arbutin was released from GBE-GG NPs in a more sustained manner and the release profiles can be accurately represented by the 1^st order kinetic model. In-vitro interactions on immortalised human keratinocytes (HaCaT) cells revealed an increase in biological membrane permeability as well as the absence of cellular toxicity at application pertinent concentrations. No substantial haemolytic activity appeared and flow cytometry analysis revealed effective cellular uptake, suggesting their potential as promising nanocarriers for percutaneous delivery that warrants further comprehensive research.

Carnosine-Modified Fullerene as a Highly Enhanced ROS Scavenger for Mitigating Acute Oxidative Stress

Fullerenes are known as highly efficient scavengers for reactive oxygen species (ROSs). In this study, a carnosine-modified fullerene derivative (C₆₀-Car) was synthesized via a one-step nucleophilic addition reaction. C₆₀-Car forms nanoparticles (NPs) readily in water at neutral pH and room temperature through self-assembly. The C₆₀-Car NPs were found to possess good water solubility, biocompatibility, and excellent ROSs scavenging capability. The scavenging efficiency of ROSs is as high as 92.49% and significantly better than that of hydroxyfullerene (C₆₀-OH NPs, 70.92%) and l-carnosine. Furthermore, C₆₀-Car NPs showed strong cytoprotective ability against H₂O₂-induced damage to the normal human fetal hepatocyte cells (L-02) and human epidermal keratinocytes-adult (HEK-a) cells at a lower concentration of 2.5 μM. In contrast, C₆₀-OH NPs showed a minor cytoprotective effect on cells at a high concentration of 10 μM. The excellent properties of such a fullerene derivative, C₆₀-Car, can be attributed largely to the involvement of l-carnosine with biological activity and antioxidant property, which make it better for biomedicine, and it may provide a new strategy for mitigating acute oxidative stress based on fullerene materials.

Fighting Hypoxia to Improve PDT

Photodynamic therapy (PDT) has drawn great interest in recent years mainly due to its low side effects and few drug resistances. Nevertheless, one of the issues of PDT is the need for oxygen to induce a photodynamic effect. Tumours often have low oxygen concentrations, related to the abnormal structure of the microvessels leading to an ineffective blood distribution. Moreover, PDT consumes O2. In order to improve the oxygenation of tumour or decrease hypoxia, different strategies are developed and are described in this review: 1) The use of O2 vehicle; 2) the modification of the tumour microenvironment (TME); 3) combining other therapies with PDT; 4) hypoxia-independent PDT; 5) hypoxia-dependent PDT and 6) fractional PDT.

Photo-triggered gadofullerene: enhanced cancer therapy by combining tumor vascular disruption and stimulation of anti-tumor immune responses

Efficient treatment of primary tumor and preventing cancer metastasis present intriguing alternatives to cancer therapy. Herein, for the first time, we reported the photo-triggered nano-gadofullerene (Gd@C₈₂-Ala, abbreviated Gd-Ala) induced malignant tumor vascular disruption by shortening the light interval between Gd-Ala administration and light illumination, where oxygen in blood vessels was employed efficiently to produce cytotoxic reactive oxygen species (ROS). The produced ROS could not only destroy the tumor cells but also devastate the vascular endothelial cells corresponding to the loss of intercellular junctions and vessels disruption. Notably, the irradiated Gd-Ala could enhance dendritic cells (DCs) maturation, which further secreted tumor necrosis factor-α (TNF-α) and interleukin-12 (IL)-12, and then activated T lymphocytes by up-regulation of cluster of differentiation CD4⁺ and CD8⁺ T lymphocytes. Furthermore, the down-regulation of matrix metalloprotein 2 (MMP2) and MMP9 also reduce the rate of tumor metastasis. This work explored a new biomedical application of gadofullerene, thereby providing a smart carbon nanomaterial candidate for tumor ablation and inhibition of cancer metastasis.

Designing an Amino-Fullerene Derivative C70-(EDA)8 to Fight Superbacteria

Along with the rapid appearance of superbacteria with multidrug resistance, it is a challenge to develop new antibacterial materials to address this big issue. Herein, we report a novel amine group-modified fullerene derivative (C₇₀-(ethylenediamine)₈ abrr. C₇₀-(EDA)₈), which reveals a high performance in killing superbacteria, and most importantly, it shows negligible toxicity to the mammalian cells. The strong antibacterial ability of this material was attributed to its unique molecular structure. On one hand, amino groups on the EDA part make it easy to affix onto the outer membrane of multidrug resistance Escherichia coli by electrostatic interactions. On the other hand, the hydrophobic surface on the C₇₀ part makes it easy to form a strong hydrophobic interaction with the inner membrane of bacteria. Finally, C₇₀-(EDA)₈ leads to the cytoplast leakage of superbacteria. In contrast, the C₇₀-(EDA)₈ is nontoxic for mammalian cells due to different distributions of the negative charges in the cell membrane. In vivo studies indicated that C₇₀-(EDA)₈ mitigated bacterial infection and accelerated wound healing by regulating the immune response and secretion of growth factors. Our amine group-based fullerene derivatives are promising for clinical treatment of wound infection and offer a new way to fight against the superbacteria.

Hydrangea-structured tumor microenvironment responsive degradable nanoplatform for hypoxic tumor multimodal imaging and therapy

Developing new strategies to alleviate tumor hypoxia and enhance the therapeutic efficacy towards solid tumors is of great significance to tumor therapy. Herein, to overcome tumor hypoxia, specifically designed aza-BODIPY photosensitizer is co-loaded with anti-cancer drug (doxorubicin, DOX) onto the hydrangea-structured MnO₂ nanoparticles, and a tumor microenvironment (TME) responsive degradable nanoplatform (MDSP NP) is established. MDSP NPs (∼54 nm), with near infrared absorption (∼853 nm), can be rapidly dissociated to generate oxygen in response to TME, whereby improving tumor hypoxia, in favor of effective drugs release and enhanced chemo/photodynamic therapy. Revealed by in vivo fluorescence and photoaccoustic imaging, MDSP NPs are preferential accumulated at tumor site. Confirmed by photothermal imaging, MDSP NPs can induce hyperthermia to relieve hypoxia, promote the uptake of therapeutic nanoparticles, and further reduce the resistance and improve the therapeutic efficiency. As a result, a remarkable synergistic tumor chemo/photodynamic/photothermal therapy with hydrangea-structured TME responsive oxygen-self-generation nanoplatform is confirmed by both in vitro and in vivo studies, testifying its great potential for hypoxic tumor treatment in clinical application.

Oxygen Self-Production Red Blood Cell Carrier System for MRI Mediated Cancer Therapy: Ferryl-Hb, Sonodynamic, and Chemical Therapy

Hypoxia in tumors can lead to insufficient oxygen supply during sonodynamic therapy (SDT), which in turn strengthens tumor resistance to sonodynamic efficacy. To conquer hypoxia in tumors and improve the treatment effectiveness, we developed oxygen self-production red blood cell (RBC) carrier system to decompose tumor endogenic H₂O₂ into O₂ and combine triplex cancer therapy: ferryl-hemoglobin (ferryl-Hb), sonodynamic, and chemical therapy. Both hydrophilic sonosensitizer and doxorubicin (DOX) were encapsulated inside RBCs (DOX/Mn-TPPS@RBCs). The drug release can be improved by combining the effects of H₂O₂ and ultrasonic irradiation. Here, we introduced a contrast agent, meso-tetra (4-sulfonatephenyl) porphyrinate manganese(III) complex (Mn-TPPS), which could be used to enhance the signal intensity of magnetic resonance imaging (MRI) of the tumor site. The feasibility of Mn-TPPS as a sonosensitizer was investigated during SDT. Importantly, DOX/Mn-TPPS@RBCs overcame hypoxia in the tumor and improved the efficacy of SDT owing to the O₂ generation by the catalase-catalyzed decomposition of tumor endogenic H₂O₂. Hemoglobin was simultaneously oxidized into highly oxidative ferryl-Hb species by H₂O₂ and reactive oxygen species, resulting in cytotoxicity. Overall, this drug delivery system is a promising therapeutic agent involving in situ production of oxygen inside the tumor, triplex therapy, and MRI.

Nano-graphene oxide-manganese dioxide nanocomposites for overcoming tumor hypoxia and enhancing cancer radioisotope therapy

While radiotherapy (RT) is commonly used in clinics for cancer treatment, the therapeutic efficiency is not satisfactory owing to the existence of the hypoxic tumor microenvironment which seriously affects the efficiency of RT. Herein, we design polyethylene glycol (PEG)-modified reduced nano-graphene oxide-manganese dioxide (rGO-MnO₂-PEG) nanocomposites to trigger oxygen generation from H₂O₂ to reduce the tumor hypoxic microenvironments. We use the radioisotope, ¹³¹I labeled rGO-MnO₂-PEG nanocomposites as therapeutic agents for in vivo tumor radioisotope therapy (RIT), achieving excellent tumor killing and further enhancing the therapeutic efficiency of RIT. More importantly, the dissolution of MnO₂ under acidic conditions and the redox process during the catalytic pathway of H₂O₂ decomposition in the cellular microenvironment direct to the production of an enormous amount of Mn²⁺ which has been used as a contrast agent for magnetic resonance imaging (MRI). Our proposed work provides a strategy to trigger oxygen formation via an internal stimulus to enhance imaging-guided RIT efficiency.

The application of titanium dioxide, zinc oxide, fullerene, and graphene nanoparticles in photodynamic therapy

Nanoparticles (NPs) have been shown to have good ability to improve the targeting and delivery of therapeutics. In the field of photodynamic therapy (PDT), this targeting advantage of NPs could help ensure drug delivery at specific sites. Among the commonly reported NPs for PDT applications, NPs from zinc oxide, titanium dioxide, and fullerene are commonly reported. In addition, graphene has also been reported to be used as NPs albeit being relatively new to this field. In this context, the present review is organized by these different NPs and contains numerous research works related to PDT applications. The effectiveness of these NPs for PDT is discussed in detail by collecting all essential information described in the literature. The information thus assembled could be useful in designing new NPs specific for PDT and/or PTT applications in the future.

C60@lysozyme: a new photosensitizing agent for photodynamic therapy

C₆₀@lysozyme showed significant visible light-induced singlet oxygen generation in a physiological environment, indicating the potential of this hybrid as an agent for photodynamic therapy.

Carbon-Based Materials for Photo-Triggered Theranostic Applications

Carbon-based nanomaterials serve as a type of smart material for photo-triggered disease theranostics. The inherent physicochemical properties of these nanomaterials facilitate their use for less invasive treatments. This review summarizes the properties and applications of materials including fullerene, nanotubes, nanohorns, nanodots and nanographenes for photodynamic nanomedicine in cancer and antimicrobial therapies. Carbon nanomaterials themselves do not usually act as photodynamic therapy (PDT) agents owing to the high hydrophobicity, however, when the surface is passivated or functionalized, these materials become great vehicles for PDT. Moreover, conjugation of carbonaceous nanomaterials with the photosensitizer (PS) and relevant targeting ligands enhances properties such as selectivity, stability, and high quantum yield, making them readily available for versatile biomedical applications.

A Versatile and Clearable Nanocarbon Theranostic Based on Carbon Dots and Gadolinium Metallofullerene Nanocrystals

Nanocarbons such as carbon nanotubes, graphene derivatives, and carbon nanohorns have illustrated their potential uses as cancer theranostics owing to their intrinsic fluorescence or NIR absorbance as well as superior cargo loading capacity. However, some problems still need to be addressed, such as the fates and long-term toxicology of different nanocarbons in vivo and the improvement of their performance in various biomedical imaging-guided cancer therapy systems. Herein, a versatile and clearable nanocarbon theranostic based on carbon dots (CDs) and gadolinium metallofullerene nanocrystals (GFNCs) is first developed, in which GFNCs enhance the tumor accumulation of CDs, and CDs enhance the relaxivity of GFNCs, leading to an efficient multimodal imaging-guided photodynamic therapy in vivo without obvious long-term toxicity. Furthermore, biochemical analysis reveals that the novel nanotheranostic can harmlessly eliminate from the body in a reasonable period of time after exerting diagnostic and therapeutic function.

Fullerene/photosensitizer nanovesicles as highly efficient and clearable phototheranostics with enhanced tumor accumulation for cancer therapy

A novel phototheranostic platform based on tri-malonate derivative of fullerene C70 (TFC70)/photosensitizer (Chlorin e6, Ce6) nanovesicles (FCNVs) has been developed for effective tumor imaging and treatment. The FCNVs were prepared from amphiphilic TFC70-oligo ethylene glycol -Ce6 molecules. The developed FCNVs possessed the following advantages: (i) high loading efficiency of Ce6 (up to ∼57 wt%); (ii) efficient absorption in near-infrared light region; (iii) enhanced cellular uptake efficiency of Ce6 in vitro and in vivo; (iv) good biocompatibility and total clearance out from the body. These unique properties suggest that the as-prepared FCNVs could be applied as an ideal theranostic agent for simultaneous imaging and photodynamic therapy of tumor. This finding may provide a good solution to highly efficient phototheranostic applications based on fullerene derivatives fabricated nanostructures.

Covalently Assembled Dipeptide Nanospheres as Intrinsic Photosensitizers for Efficient Photodynamic Therapy in Vitro

Monodispersed diphenylalanine-based nanospheres with excellent biocompatibility are fabricated through a facile covalent reaction-induced assembly. Interestingly, the nanospheres exhibit red autofluorescence. Most importantly, such assembled dipeptide nanospheres can serve as intrinsic photosensitizer to convert O2 to singlet oxygen ((1) O2 ). Thus, photodynamic therapy in vitro can be achieved effectively. The versatile strategy could be extended to other biomolecules containing a primary amine group for the fabrication of potential intrinsic photosensitizers.

The positive influence of fullerene derivatives bonded to manganese(III) porphyrins on water proton relaxation

Manganese-porphyrin compounds as MRI contrast agents have drawn particular attention due to high relaxivities and unique biodistribution. It has been reported that the charge density of the metal center and steric decompression of the substituents, rather than rotational correlation time, were the key factors to determine the relaxivities of manganese(III) porphyrins. In this study, [6,6]-phenyl-C61-butyric acid (PC61BA) was introduced into 5-(4-aminophenyl)-10,15,20-tris (4-sulfonatophenyl) porphyrin (APTSPP) to investigate the influence on water proton relaxation. The obtained PC61BA-APTSPP-Mn possesses a relaxivity of 19.2 mM(-1) s(-1), which is greater than that of Mn-APTSPP (11.2 mM(-1) s(-1)) and clinically used Gd-DTPA (4.1 mM(-1) s(-1)) at 0.5 T, and even more effective compared with those binding manganese(III) porphyrins to certain macromolecules. It was reasonably speculated that the high relaxivity of PC61BA-APTSPP-Mn should ascribe to the charge density variation of Mn(III) and steric decompression induced by PC61BA. Both fluorescence emission spectra and cyclic voltammetry results verified the presence of electronic communication between PC61BA and APTSPP-Mn. In addition, the hydrodynamic diameter of PC61BA-APTSPP-Mn aggregates was much smaller than that of APTSPP-Mn aggregates, which may contribute to the higher relaxivity by inhibiting the formation of dimers of APTSPP-Mn. Therefore, the introduction of fullerene derivatives is suggested to be a good strategy for the improvement of the relaxivities of manganese(III) porphyrins.

Efficient singlet oxygen generation from sugar pendant C60 derivatives for photodynamic therapy

Glc-pendant C₆₀ compounds exhibited high photocytotoxicity against HeLa cells due to the more efficient singlet oxygen generation as compared with that of Glc-pendant azafulleroids.