Graphene Oxide Noncovalent Photosensitizer and Its Anticancer Activity In Vitro

Enhanced Electrochemical Performances of Heterostructures Based on the Colloidal Association of Graphene Oxide and Titanium Disulfide Nanosheets

Due to the large proliferation of electrical devices combined with the ecological transition for carbon neutrality in various modern countries, the demand for compact and efficient portable energy sources is continuously increasing. In this research work, we have developed electrochemical energy storage heterostructures based on graphene oxides (GOs) and titanium disulfide (TiS2) nanosheets of different lateral sizes through a facile colloidal association thanks to the opposite electric charges of the two types of nanosheets. Large GO (LGO) served as a template system to organize TiS2 nanosheets at different loadings, of which incorporation prevented any restacking of the layered graphitic structure. While large nanosheets led to the decoration of TiS2 aggregates including Li+ cations on LGO, the association of the nanosheets of different compositions but equivalent sizes drove the formation of an interstratified organization of the nanosheets. The singular organization within GO and TiS2 nanosheets remained after a hydrothermal reduction process, leading to heterostructure materials with a large specific surface area and capacitance of 113 F/g obtained in 6 M KOH aqueous solution. These outstanding electrochemical performances, drastically enhanced by about 41% from those of the individual reduced GO (capacitance of 80 F/g) used as a collector for the electric carriers, suggest that the developed heterostructures present a possible application as electrochemical energy storage technology materials for supercapacitor applications.

NI-BODIPY-GO Nanocomposites for Targeted PDT

Three multifunctional targeted NI-BODIPYs (10-12) and GO-(10-12) nanocarriers were fabricated. NI-BODIPYs are designed to facilitate non-covalent interaction with graphene oxide (GO) and target toward cancer cells for specific recognition with glucose moieties while efficiently producing singlet oxygen. We probed detailed characterization, fundamental photophysical/photochemical properties, and interactions with GO of such triplet photosensitizers and nanocarriers. The effect of the formation of nanohybrids with GO on singlet oxygen formation as well as on the efficacies of the molecules in terms of in vitro killing of cancer cells was evaluated with K562 human chronic myelogenous leukemia cells. Amazingly, it was observed that GO exhibited favorable interactions with the NI-BODIPY dyads and promoted the formation of singlet oxygen, while not showing any dark toxicity.

Graphene Incorporated Electrospun Nanofiber for Electrochemical Sensing and Biomedical Applications: A Critical Review

The extraordinary material graphene arrived in the fields of engineering and science to instigate a material revolution in 2004. Graphene has promptly risen as the super star due to its outstanding properties. Graphene is an allotrope of carbon and is made up of sp²-bonded carbon atoms placed in a two-dimensional honeycomb lattice. Graphite consists of stacked layers of graphene. Due to the distinctive structural features as well as excellent physico-chemical and electrical conductivity, graphene allows remarkable improvement in the performance of electrospun nanofibers (NFs), which results in the enhancement of promising applications in NF-based sensor and biomedical technologies. Electrospinning is an easy, economical, and versatile technology depending on electrostatic repulsion between the surface charges to generate fibers from the extensive list of polymeric and ceramic materials with diameters down to a few nanometers. NFs have emerged as important and attractive platform with outstanding properties for biosensing and biomedical applications, because of their excellent functional features, that include high porosity, high surface area to volume ratio, high catalytic and charge transfer, much better electrical conductivity, controllable nanofiber mat configuration, biocompatibility, and bioresorbability. The inclusion of graphene nanomaterials (GNMs) into NFs is highly desirable. Pre-processing techniques and post-processing techniques to incorporate GNMs into electrospun polymer NFs are precisely discussed. The accomplishment and the utilization of NFs containing GNMs in the electrochemical biosensing pathway for the detection of a broad range biological analytes are discussed. Graphene oxide (GO) has great importance and potential in the biomedical field and can imitate the composition of the extracellular matrix. The oxygen-rich GO is hydrophilic in nature and easily disperses in water, and assists in cell growth, drug delivery, and antimicrobial properties of electrospun nanofiber matrices. NFs containing GO for tissue engineering, drug and gene delivery, wound healing applications, and medical equipment are discussed. NFs containing GO have importance in biomedical applications, which include engineered cardiac patches, instrument coatings, and triboelectric nanogenerators (TENGs) for motion sensing applications. This review deals with graphene-based nanomaterials (GNMs) such as GO incorporated electrospun polymeric NFs for biosensing and biomedical applications, that can bridge the gap between the laboratory facility and industry.

Multimodal Imaging and Phototherapy of Cancer and Bacterial Infection by Graphene and Related Nanocomposites

The advancements in nanotechnology and nanomedicine are projected to solve many glitches in medicine, especially in the fields of cancer and infectious diseases, which are ranked in the top five most dangerous deadly diseases worldwide by the WHO. There is great concern to eradicate these problems with accurate diagnosis and therapies. Among many developed therapeutic models, near infra-red mediated phototherapy is a non-invasive technique used to invade many persistent tumors and bacterial infections with less inflammation compared with traditional therapeutic models such as radiation therapy, chemotherapy, and surgeries. Herein, we firstly summarize the up-to-date research on graphene phototheranostics for a better understanding of this field of research. We discuss the preparation and functionalization of graphene nanomaterials with various biocompatible components, such as metals, metal oxides, polymers, photosensitizers, and drugs, through covalent and noncovalent approaches. The multifunctional nanographene is used to diagnose the disease with confocal laser scanning microscopy, magnetic resonance imaging computed tomography, positron emission tomography, photoacoustic imaging, Raman, and ToF-SMIS to visualize inside the biological system for imaging-guided therapy are discussed. Further, treatment of disease by photothermal and photodynamic therapies against different cancers and bacterial infections are carefully conferred herein along with challenges and future perspectives.

Multifunctional graphene oxide nanoparticles for drug delivery in cancer

Recent advancements in nanotechnology have enabled us to develop sophisticated multifunctional nanoparticles or nanosystems for targeted diagnosis and treatment of several illnesses, including cancers. To effectively treat any solid tumor, the therapy should preferably target just the malignant cells/tissue with minor damage to normal cells/tissues. Graphene oxide (GO) nanoparticles have gained considerable interest owing to their two-dimensional planar structure, chemical/mechanical stability, excellent photosensitivity, superb conductivity, high surface area, and good biocompatibility in cancer therapy. Many compounds have been functionalized on the surface of GO to increase their biological applications and minimize cytotoxicity. The review presents an overview of the physicochemical characteristics, strategies for various modifications, toxicity and biocompatibility of graphene and graphene oxide, current trends in developing GO-based nano constructs as a drug delivery cargo and other biological applications, including chemo-photothermal therapy, chemo-photodynamic therapy, bioimaging, and theragnosis in cancer. Further, the review discusses the challenges and opportunities of GO, GO-based nanomaterials for the said applications. Overall, the review focuses on the therapeutic potential of strategically developed GO nanomedicines and comprehensively discusses their opportunities and challenges in cancer therapy.

Smart nanocomposite assemblies for multimodal cancer theranostics

Despite great strides in anticancer research, performance statistics of current treatment modalities remain dismal, highlighting the need for safe, efficacious strategies for tumour mitigation. Non-invasive fusion technology platforms combining photodynamic, photothermal and hyperthermia therapies have emerged as alternate strategies with potential to meet many of the unmet clinical demands in the domain of cancer. These therapies make use of metallic and magnetic nanoparticles with light absorbing properties, which are manipulated to generate either reactive cytotoxic oxygen species or heat for tumour ablation. Combination therapies integrating light, heat and magnetism-mediated nanoplatforms with the conventional approaches of chemotherapy, radiotherapy and surgery are emerging as precision medicine for targeted interventions against cancer. This article aims to compile recent developments of advanced nanocomposite assemblies that integrate multimodal therapeutics for cancer treatment. Amalgamation of various effective, non-invasive technological platforms such as photodynamic therapy (PDT), photothermal therapy (PTT), magnetic hyperthermia (MHT), and chemodynamic therapy (CDT) have tremendous potential in presenting safe and efficacious solutions to the formidable challenges in cancer therapeutics.

The Role of Graphene Oxide Nanocarriers in Treating Gliomas

Gliomas are the most common primary malignant tumors of the central nervous system, and their conventional treatment involves maximal safe surgical resection combined with radiotherapy and temozolomide chemotherapy; however, this treatment does not meet the requirements of patients in terms of survival and quality of life. Graphene oxide (GO) has excellent physical and chemical properties and plays an important role in the treatment of gliomas mainly through four applications, viz. direct killing, drug delivery, immunotherapy, and phototherapy. This article reviews research on GO nanocarriers in the treatment of gliomas in recent years and also highlights new ideas for the treatment of these tumors.

Biomedical Applications of Electrospun Graphene Oxide

Graphene oxide (GO) has broad potential in the biomedical sector. The oxygen-abundant nature of GO means the material is hydrophilic and readily dispersible in water. GO has also been known to improve cell proliferation, drug loading, and antimicrobial properties of composites. Electrospun composites likewise have great potential for biomedical applications because they are generally biocompatible and bioresorbable, possess low immune rejection risk, and can mimic the structure of the extracellular matrix. In the current review, GO-containing electrospun composites for tissue engineering applications are described in detail. In addition, electrospun GO-containing materials for their use in drug and gene delivery, wound healing, and biomaterials/medical devices have been examined. Good biocompatibility and anionic-exchange properties of GO make it an ideal candidate for drug and gene delivery systems. Drug/gene delivery applications for electrospun GO composites are described with a number of examples. Various systems using electrospun GO-containing therapeutics have been compared for their potential uses in cancer therapy. Micro- to nanosized electrospun fibers for wound healing applications and antimicrobial applications are explained in detail. Applications of various GO-containing electrospun composite materials for medical device applications are listed. It is concluded that the electrospun GO materials will find a broad range of biomedical applications such as cardiac patches, medical device coatings, sensors, and triboelectric nanogenerators for motion sensing and biosensing.

Recent advances in graphene-family nanomaterials for effective drug delivery and phototherapy

INTRODUCTION

Owing to the unique properties of graphene, including large specific surface area, excellent thermal conductivity, and optical absorption, graphene-family nanomaterials (GFNs) have attracted extensive attention in biomedical applications, particularly in drug delivery and phototherapy.

AREAS COVERED

In this review, we point out several challenges involved in the clinical application of GFNs. Then, we provide an overview of the most recent publications about GFNs in biomedical applications, including diverse strategies for improving the biocompatibility, specific targeting and stimuli-responsiveness of GFNs for drug delivery, codelivery of drug and gene, photothermal therapy, photodynamic therapy, and multimodal combination therapy.

EXPERT OPINION

Although the application of GFNs is still in the preclinical stage, rational modification of GFNs with functional elements or making full use of GFNs-based multimodal combination therapy might show great potential in biomedicine for clinical application.

Fabrication of pH-sensitive graphene oxide-Benazepril carrier as biosafety controlled release systems

A novel graphene oxide (GO)-based carrier was fabricated for the controlled release of Benazepril (BENA). Freeze dried samples of GO-BENA carrier were prepared for controlled drug release at different pHs (pH = 2, 7, and 10) and release kinetics indicate BENA desorption from GO is by Fickian diffusion. The BENA yield from the carrier amounted to ~55% of the adsorbed material in a strongly acidic medium after 50 h. Binding fractions of BENA to 10 mg/L GO was determined for different solution concentrations of the drug. In vitro assays of cell proliferation (WST-1 kit), cell structural integrity (LDH kit) and flow cytometric indicators of necrosis in three different cell lines (CACO-2, SGC-7901, and primary mouse hepatic fibroblast) all demonstrated that the GO carrier had a good biocompatibility. The pH-dependent release sensitivity of the GO-based carrier suggests that it is a potential candidate for use in the controlled release of drugs in the acidic environment of the stomach.

Red-Emissive Carbon Quantum Dots for Nuclear Drug Delivery in Cancer Stem Cells

Large doses of anticancer drugs entering cancer cell nuclei are found to be effective at killing cancer cells and increasing chemotherapeutic effectiveness. Here we report red-emissive carbon quantum dots, which can enter into the nuclei of not only cancer cells but also cancer stem cells. After doxorubicin was loaded at the concentration of 30 μg/mL on the surfaces of carbon quantum dots, the average cell viability of HeLa cells was decreased to only 21%, while it was decreased to 50% for free doxorubicin. The doxorubicin-loaded carbon quantum dots also exhibited a good therapeutic effect by eliminating cancer stem cells. This work provides a potential strategy for developing carbon quantum-dot-based anticancer drug carriers for effective eradication of cancers.

Sonochemically N-functionalized graphene oxide towards optically active photoluminescent bioscaffold

Herein, Nitrogen functionalized graphene oxide (N-f-GrO) has been synthesized using the sonochemical method. 2-Aminopyrimidine (APD) was used as a precursor for covalent functionalization with graphene oxide [f-(APD)GrO] as N-f-GrO which was ascertained with XPS. The involvement of arylamine group and formation of covalent bond over GrO surface was confirmed with high resolution C1s spectrum of f-(APD)GrO. Also, the signature of N1s peak in the survey spectrum of f-(APD)GrO has endorsed the surface modification of GrO through covalent functionalization. A bathochromic shift was observed for f-(APD)GrO in UV and enhanced weight loss of 91.39% at 191.80 °C, confirms a facile functionalization of GrO via formation of amide bond, where the terminal -OH portal of carboxylic group is substituted by 2-Aminopyrimidine. Moreover, the formation of f-(APD)GrO was investigated with various analytical techniques like Raman, XRD and FTIR. The surface morphology and topography have been understood by using HRTEM/SAED, AFM, and SEM analysis. The synthesized f-(APD)GrO shows potential optically active photoluminescence properties and higher potency towards biological insight. The identified photoluminescence (PL) peaks at 3.78, 3.21 2.01 and 1.64 eV indicate photon emission including an orange optical transition at 2.01 eV. The multiple peaks in a PL spectrum are due to radiative and non-radiative recombinations which are also associated with excess hole (h⁺)-electron (e^-) trapping on the surface to restrict the recombinations of e^- and h⁺. The biological activity of N-f-GrO has been explored with Sulforhodamine B (SRB) assay on HaCaT and Vero cell lines. The concentration-dependent cell viabilities have been observed a maximum at 20 µg/ml for HaCaT and at 10 µg/ml for Vero cell lines at testing concentration range of 10-80 μg mL^-1. The significant morphological impact on cell lines confirms the cytocompatibility behaviour. Therefore, the synergistic impact of various properties of f-(APD)GrO can be further explored to study its significance as nanocarrier for photosensitive biomedical response.

Enhancement of Photodynamic Cancer Therapy by Physical and Chemical Factors

The viable use of photodynamic therapy (PDT) in cancer therapy has never been fully realized because of its undesirable effects on healthy tissues. Herein we summarize some physicochemical factors that can make PDT a more viable and effective option to provide future oncological patients with better-quality treatment options. These physicochemical factors include light sources, photosensitizer (PS) carriers, microwaves, electric fields, magnetic fields, and ultrasound. This Review is meant to provide current information pertaining to PDT use, including a discussion of in vitro and in vivo studies. Emphasis is placed on the physicochemical factors and their potential benefits in overcoming the difficulty in transitioning PDT into the medical field. Many advanced techniques, such as employing X-rays as a light source, using nanoparticle-loaded stem cells and bacteriophage bio-nanowires as a photosensitizer carrier, as well as integration with immunotherapy, are among the future directions.

pH-Sensitive graphene oxide conjugate purpurin-18 methyl ester photosensitizer nanocomplex in photodynamic therapy

A GO–Pu18 composite showed excellent photodynamic bioactivity and pH-sensitive drug release behavior.

Developing the next generation of graphene-based platforms for cancer therapeutics: The potential role of reactive oxygen species

Graphene has a promising future in applications such as disease diagnosis, cancer therapy, drug/gene delivery, bio-imaging and antibacterial approaches owing to graphene's unique physical, chemical and mechanical properties alongside minimal toxicity to normal cells, and photo-stability. However, these unique features and bioavailability of graphene are fraught with uncertainties and concerns for environmental and occupational exposure. Changes in the physicochemical properties of graphene affect biological responses including reactive oxygen species (ROS) production. Lower production of ROS by currently available theranostic agents, e.g. magnetic nanoparticles, carbon nanotubes, gold nanostructures or polymeric nanoparticles, restricts their clinical application in cancer therapy. Oxidative stress induced by graphene accumulated in living organs is due to acellular factors which may affect physiological interactions between graphene and target tissues and cells. Acellular factors include particle size, shape, surface charge, surface containing functional groups, and light activation. Cellular responses such as mitochondrial respiration, graphene-cell interactions and pH of the medium are also determinants of ROS production. The mechanisms of ROS production by graphene and the role of ROS for cancer treatment, are poorly understood. The aim of this review is to set the theoretical basis for further research in developing graphene-based theranostic platforms.

Carbon nanomaterials in oncology: an expanding horizon

Carbon nanomaterials have been attracting attention in oncology for the development of safe and effective cancer nanomedicines in increasing improved patient compliance for generally recognized as safe (GRAS) prominence. Toxicity, safety and efficacy of carbon nanomaterials are the major concerns in cancer theranostics. Various parameters such as particle size and shape or surface morphology, surface charge, composition, oxidation and nonoxidative-stress-related mechanisms are prone to toxicity of the carbon nanomaterials. Currently, few cancer-related products have been available on the market, although some are underway in preclinical and clinical phases. Thus, our main aim is to provide comprehensive details on the carbon nanomaterials in oncology from the past two decades for patient compliance and safety.

Nanostructures for NIR light-controlled therapies

In general, effective clinical treatment demands precision medicine, which requires specific perturbation to disease cells with no damage to normal tissue. Thus far, guaranteeing that selective therapeutic effects occur only at targeted disease areas remains a technical challenge. Among the various endeavors to achieve such an outcome, strategies based on light-controlled therapies have received special attention, mostly due to their unique advantages, including the low-invasive property and the capability to obtain spatial and temporal precision at the targeted sites via specific wavelength light irradiation. However, most conventional light-mediated therapies, especially those based on short-wavelength UV or visible light irradiation, have potential issues including limited penetration depth and harmful photo damage to healthy tissue. Therefore, the implemention of near-infrared (NIR) light illumination, which can travel into deeper tissues without causing obvious photo-induced cytotoxcity, has been suggested as a preferable option for precise phototherapeutic applications in vitro and in vivo. In this article, an overview is presented of existing therapeutic applications through NIR light-absorbed nanostructures, such as NIR light-controlled drug delivery, NIR light-mediated photothermal and photodynamic therapies. Potential challenges and relevant future prospects are also discussed.

Recent advances in carbon based nanosystems for cancer theranostics

This review deals with four different types of carbon allotrope based nanosystems and summarizes the results of recent studies that are likely to have applications in cancer theranostics. We discuss the applications of these nanosystems for cancer imaging, drug delivery, hyperthermia, and PDT/TA/PA.

Breaking the reduced glutathione-activated antioxidant defence for enhanced photodynamic therapy

Photodynamic therapy (PDT) has been applied in cancer treatment by utilizing reactive oxygen species (ROSs) to kill cancer cells.

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.

Graphene-based nanosheets for delivery of chemotherapeutics and biological drugs

Graphene-based nanosheets (GNS), including graphenes, graphene oxides and reduced graphene oxides, have properties suitable for delivery of various molecules. With their two-dimensional structures, GNS provide relatively high surface areas and capacity for non-covalent π-π stacking and hydrophobic interactions with various drug molecules. Currently, GNS-based delivery applications extend to chemotherapeutics as well as biological drugs, including nucleic acid drugs, proteins, and peptides. Surfaces of GNS have been modified with various polymers, such as polyethylene glycol and biopolymers, which enhance biocompatibility and increase drug loading. Anticancer drugs are prominent among chemotherapeutic agents tested, and have been loaded onto GNS with relatively high loading capacities compared with other nanocarriers. For enhanced distribution to specific tissues, GNS have been covalently or non-covalently modified with targeting ligands, including folic acid, transferrins, and others. In this review, we cover the current status of GNS for delivery of anticancer chemotherapeutics and biological drugs, with a focus on nucleic acid drugs. Remaining challenges for the application of GNS for drug-delivery systems and future perspectives are also addressed.

Hyaluronic Acid-Modified Multifunctional Q-Graphene for Targeted Killing of Drug-Resistant Lung Cancer Cells

Considering the urgent need to explore multifunctional drug delivery system for overcoming multidrug resistance, we prepared a new nanocarbon material Q-Graphene as a nanocarrier for killing drug-resistant lung cancer cells. Attributing to the introduction of hyaluronic acid and rhodamine B isothiocyanate (RBITC), the Q-Graphene-based drug delivery system was endowed with dual function of targeted drug delivery and fluorescence imaging. Additionally, doxorubicin (DOX) as a model drug was loaded on the surface of Q-Graphene via π-π stacking. Interestingly, the fluorescence of DOX was quenched by Q-Graphene due to its strong electron-accepting capability, and a significant recovery of fluorescence was observed, while DOX was released from Q-Graphene. Because of the RBITC labeling and the effect of fluorescence quenching/restoring of Q-Graphene, the uptake of nanoparticles and intracellular DOX release can be tracked. Overall, a highly promising multifunctional nanoplatform was developed for tracking and monitoring targeted drug delivery for efficiently killing drug-resistant cancer cells.

Carbon nanomaterials: multi-functional agents for biomedical fluorescence and Raman imaging

Carbon based nanomaterials have emerged over the last few years as important agents for biomedical fluorescence and Raman imaging applications. These spectroscopic techniques utilize either fluorescently labelled carbon nanomaterials or the intrinsic photophysical properties of the carbon nanomaterial. In this review article we present the utilization and performance of several classes of carbon nanomaterials, namely carbon nanotubes, carbon nanohorns, carbon nanoonions, nanodiamonds and different graphene derivatives, which are currently employed for in vitro as well as in vivo imaging in biology and medicine. A variety of different approaches, imaging agents and techniques are examined and the specific properties of the various carbon based imaging agents are discussed. Some theranostic carbon nanomaterials, which combine diagnostic features (i.e. imaging) with cell specific targeting and therapeutic approaches (i.e. drug delivery or photothermal therapy), are also included in this overview.

Graphene-based platforms for cancer therapeutics

Graphene is a multifunctional carbon nanomaterial and could be utilized to develop platform technologies for cancer therapies. Its surface can be covalently and noncovalently functionalized with anticancer drugs and functional groups that target cancer cells and tissue to improve treatment efficacies. Furthermore, its physicochemical properties can be harnessed to facilitate stimulus responsive therapeutics and drug delivery. This review article summarizes the recent literature specifically focused on development of graphene technologies to treat cancer. We will focus on advances at the interface of graphene based drug/gene delivery, photothermal/photodynamic therapy and combinations of these techniques. We also discuss the current understanding in cytocompatibility and biocompatibility issues related to graphene formulations and their implications pertinent to clinical cancer management.

Reduced graphene oxide-silver nanoparticle nanocomposite: a potential anticancer nanotherapy

Background

Graphene and graphene-based nanocomposites are used in various research areas including sensing, energy storage, and catalysis. The mechanical, thermal, electrical, and biological properties render graphene-based nanocomposites of metallic nanoparticles useful for several biomedical applications. Epithelial ovarian carcinoma is the fifth most deadly cancer in women; most tumors initially respond to chemotherapy, but eventually acquire chemoresistance. Consequently, the development of novel molecules for cancer therapy is essential. This study was designed to develop a simple, non-toxic, environmentally friendly method for the synthesis of reduced graphene oxide–silver (rGO–Ag) nanoparticle nanocomposites using Tilia amurensis plant extracts as reducing and stabilizing agents. The anticancer properties of rGO–Ag were evaluated in ovarian cancer cells.

Methods

The synthesized rGO–Ag nanocomposite was characterized using various analytical techniques. The anticancer properties of the rGO–Ag nanocomposite were evaluated using a series of assays such as cell viability, lactate dehydrogenase leakage, reactive oxygen species generation, cellular levels of malonaldehyde and glutathione, caspase-3 activity, and DNA fragmentation in ovarian cancer cells (A2780).

Results

AgNPs with an average size of 20 nm were uniformly dispersed on graphene sheets. The data obtained from the biochemical assays indicate that the rGO–Ag nanocomposite significantly inhibited cell viability in A2780 ovarian cancer cells and increased lactate dehydrogenase leakage, reactive oxygen species generation, caspase-3 activity, and DNA fragmentation compared with other tested nanomaterials such as graphene oxide, rGO, and AgNPs.

Conclusion

T. amurensis plant extract-mediated rGO–Ag nanocomposites could facilitate the large-scale production of graphene-based nanocomposites; rGO–Ag showed a significant inhibiting effect on cell viability compared to graphene oxide, rGO, and silver nanoparticles. The nanocomposites could be effective non-toxic therapeutic agents for the treatment of both cancer and cancer stem cells.

Graphene-based nanomaterials: biological and medical applications and toxicity

Graphene and its derivatives, due to a wide range of unique properties that they possess, can be used as starting material for the synthesis of useful nanocomplexes for innovative therapeutic strategies and biodiagnostics. Here, we summarize the latest progress in graphene and its derivatives and their potential applications for drug delivery, gene delivery, biosensor and tissue engineering. A simple comparison with carbon nanotubes uses in biomedicine is also presented. We also discuss their in vitro and in vivo toxicity and biocompatibility in three different life kingdoms (bacterial, mammalian and plant cells). All aspects of how graphene is internalized after in vivo administration or in vitro cell exposure were brought about, and explain how blood-brain barrier can be overlapped by graphene nanomaterials.

Emerging advances in cancer nanotheranostics with graphene nanocomposites: opportunities and challenges

As an inorganic nanomaterial, graphene nanocomposites have gained much attention in cancer nanotechnology compared with the other inorganic nanomaterial in recent times. Although a relatively new drug carrier, it has been extensively explored as a potential chemotherapeutic carrier and theranostic because of its numerous physicochemical properties, including, capability of multiple pay load, functionalization for drug targeting and photothermal effect. Despite potential benefit, its translation from bench to bed-side in cancer therapy is challenged due to its toxicity concern. Here, we discussed the present progress and future possibilities of graphene nanocomposites as a cancer theranostic. Moreover, the paper also exemplifies the effects of graphene/graphene oxide on tissues and organ functions in order to understand the extent and mechanism of toxicity.

PEGylated graphene oxide for tumor-targeted delivery of paclitaxel

Aim: The graphene oxide (GO) sheet has been considered one of the most promising carbon derivatives in the field of material science for the past few years and has shown excellent tumor-targeting ability, biocompatibility and low toxicity. We have endeavored to conjugate paclitaxel (PTX) to GO molecule and investigate its anticancer efficacy. Materials & Methods: We conjugated the anticancer drug PTX to aminated PEG chains on GO sheets through covalent bonds to get GO-PEG-PTX complexes. The tissue distribution and anticancer efficacy of GO-PEG-PTX were then investigated using a B16 melanoma cancer-bearing C57 mice model. Results: The GO-PEG-PTX complexes exhibited excellent water solubility and biocompatibility. Compared with the traditional formulation of PTX (Taxol®), GO-PEG-PTX has shown prolonged blood circulation time as well as high tumor-targeting and -suppressing efficacy. Conclusion: PEGylated graphene oxide is an excellent nanocarrier for paclitaxel for cancer targeting.

Graphene-based nanovehicles for photodynamic medical therapy

Graphene and its derivatives such as graphene oxide (GO) have been widely explored as promising drug delivery vehicles for improved cancer treatment. In this review, we focus on their applications in photodynamic therapy. The large specific surface area of GO facilitates efficient loading of the photosensitizers and biological molecules via various surface functional groups. By incorporation of targeting ligands or activatable agents responsive to specific biological stimulations, smart nanovehicles are established, enabling tumor-triggering release or tumor-selective accumulation of photosensitizer for effective therapy with minimum side effects. Graphene-based nanosystems have been shown to improve the stability, bioavailability, and photodynamic efficiency of organic photosensitizer molecules. They have also been shown to behave as electron sinks for enhanced visible-light photodynamic activities. Owing to its intrinsic near infrared absorption properties, GO can be designed to combine both photodynamic and photothermal hyperthermia for optimum therapeutic efficiency. Critical issues and future aspects of photodynamic therapy research are addressed in this review.

Enhanced fluorescence imaging guided photodynamic therapy of sinoporphyrin sodium loaded graphene oxide

Extensive research indicates that graphene oxide (GO) can effectively deliver photosensitives (PSs) by π-π stacking for photodynamic therapy (PDT). However, due to the tight complexes of GO and PSs, the fluorescence of PSs are often drastically quenched via an energy/charge transfer process, which limits GO-PS systems for photodiagnostics especially in fluorescence imaging. To solve this problem, we herein strategically designed and prepared a novel photo-theranostic agent based on sinoporphyrin sodium (DVDMS) loaded PEGylated GO (GO-PEG-DVDMS) with improved fluorescence property for enhanced optical imaging guided PDT. The fluorescence of loaded DVDMS is drastically enhanced via intramolecular charge transfer. Meanwhile, the GO-PEG vehicles can significantly increase the tumor accumulation efficiency of DVDMS and lead to an improved PDT efficacy as compared to DVDMS alone. The cancer theranostic capability of the as-prepared GO-PEG-DVDMS was carefully investigated both in vitro and in vivo. Most intriguingly, 100% in vivo tumor elimination was achieved by intravenous injection of GO-PEG-DVDMS (2 mg/kg of DVDMS, 50 J) without tumor recurrence, loss of body weight or other noticeable toxicity. This novel GO-PEG-DVDMS theranostics is well suited for enhanced fluorescence imaging guided PDT.

An efficient gold nanocarrier for combined chemo-photodynamic therapy on tumour cells

A multimodal Au@mSiO₂ nanocarrier in which AuNPs act as PDT-assistor cores and mesoporous silica shells as supporters to load two drugs.

Modulating the photo-exciting process of photosensitizer to improve in vitro phototoxicity by preparing its self-assembly nanostructures

Self-assembled photosensitizer nanostructures preparation by controlling the charge property of drug and ion strength of environment to improve photodynamic activity.

Biocompatibility of graphene oxide intravenously administrated in mice—effects of dose, size and exposure protocols

The toxicity of graphene oxide intravenously injected into mice was dramatically tuned by dose, size and exposure protocols of graphene oxide.

Synergistic anticancer activity of photo- and chemoresponsive nanoformulation based on polylysine-functionalized graphene

Multimodal therapeutic agents based on nanomaterials for cancer combination therapy have attracted increasing attention. In this report, a novel photo- and chemoactive nanohybrid was fabricated by assembling photosensitizer Zn(II)-phthalocyanine (ZnPc) and anticancer drug doxorubicin (DOX) on the biocompatible poly-l-lysine (PLL)-grafted graphene (G-PLL). This nanocomplex of G-PLL/DOX/ZnPc showed excellent physiochemical properties, including high solubility and stability in biological solutions, high drug loading efficiency, pH-triggered drug release, and ability to generalize (1)O2 under light excitation. Compared to free drug molecules, cells treated with G-PLL/DOX/ZnPc showed a higher cellular uptake. In particular, G-PLL/DOX/ZnPc elicited a remarkable synergistic anticancer activity owing to combined photodynamic and chemotherapeutic effects. The combination dose reduction indexes revealed that combining DOX with ZnPc provided strong synergistic effects (combination index < 0.1) against three cancer cell lines tested (HeLa, MCF-7, and B16). Thus, this study demonstrates programmable dual-modality therapy exemplified by G-PLL/DOX/ZnPc to synergistically treat cancers.

VEGFR targeting leads to significantly enhanced tumor uptake of nanographene oxide in vivo

Although graphene oxide (GO) has recently been considered as a highly attractive nanomaterial for future cancer imaging and therapy, it is still a major challenge to improve its in vivo tumor active targeting efficiency. Here in this full article, we demonstrated the successful and significantly enhanced in vivo tumor vasculature targeting efficacy of well-functionalized GO nanoconjugates by using vascular endothelial growth factor 121 (VEGF121) as the targeting ligand. As-developed GO nanoconjugate exhibits excellent in vivo stability, specific in vitro and in vivo vascular endothelial growth factor receptor (VEGFR) targeting, significantly enhanced tumor accumulation (>8 %ID/g) as well as high tumor-to-muscle contrast, showing great potential for future tumor targeted imaging and therapy.

Graphene oxide enhances cellular delivery of hydrophilic small molecules by co-incubation

The delivery of bioactive molecules into cells has broad applications in biology and medicine. Polymer-modified graphene oxide (GO) has recently emerged as a de facto noncovalent vehicle for hydrophobic drugs. Here, we investigate a different approach using native GO to deliver hydrophilic molecules by co-incubation in culture. GO adsorption and delivery were systematically studied with a library of 15 molecules synthesized with Gd(III) labels to enable quantitation. Amines were revealed to be a key chemical group for adsorption, while delivery was shown to be quantitatively predictable by molecular adsorption, GO sedimentation, and GO size. GO co-incubation was shown to enhance delivery by up to 13-fold and allowed for a 100-fold increase in molecular incubation concentration compared to the alternative of nanoconjugation. When tested in the application of Gd(III) cellular MRI, these advantages led to a nearly 10-fold improvement in sensitivity over the state-of-the-art. GO co-incubation is an effective method of cellular delivery that is easily adoptable by researchers across all fields.

Surface engineering of graphene-based nanomaterials for biomedical applications

Graphene-based nanomaterials have attracted tremendous interest over the past decade due to their unique electronic, optical, mechanical, and chemical properties. However, the biomedical applications of these intriguing nanomaterials are still limited due to their suboptimal solubility/biocompatibility, potential toxicity, and difficulties in achieving active tumor targeting, just to name a few. In this Topical Review, we will discuss in detail the important role of surface engineering (i.e., bioconjugation) in improving the in vitro/in vivo stability and enriching the functionality of graphene-based nanomaterials, which can enable single/multimodality imaging (e.g., optical imaging, positron emission tomography, magnetic resonance imaging) and therapy (e.g., photothermal therapy, photodynamic therapy, and drug/gene delivery) of cancer. Current challenges and future research directions are also discussed and we believe that graphene-based nanomaterials are attractive nanoplatforms for a broad array of future biomedical applications.

Cyclic RGD-modified chitosan/graphene oxide polymers for drug delivery and cellular imaging

Polymers based on cyclic RGD-modified chitosan/graphene oxide are investigated in this paper as an innovative type of drug delivery system for hepatocellular carcinoma-targeted therapy and imaging. The system was prepared using a simple noncovalent method by coating drug-loaded graphene oxide (GO) with cyclic RGD-modified chitosan (RC). The results show that an efficient loading of doxorubicin (DOX) on GO (1.00mg/mg) was obtained. The system exhibits a pH-responsive behavior because of the hydrogen bonding interaction between GO and RC, and may be very stable under physiological conditions but with release at a lower pH (tumor environment). In addition, cellular uptake and proliferation studies using hepatoma cells (Bel-7402, SMMC-7721, HepG2) indicated that the cRGD-modified chitosan/graphene oxide polymer could recognize hepatoma cells and promote drug uptake by the cells, especially for cells overexpressing integrins. Together, these results demonstrate that the RC/GO polymers provide a multifunctional drug delivery system with the ability to target hepatocarcinoma cells, and are pH-responsive and can be efficiently loaded with a number of therapeutic agents for biomedical applications.

Near-infrared light-responsive nanomaterials in cancer therapeutics

Near-infrared light sensitive nanomaterials provide ideal nanoplatforms in site specific noninvasive cancer therapy.