Recent progress of functionalised graphene oxide in cancer therapy

Radiofrequency driving antitumor effect of graphene oxide-based nanocomposites: a Hill model analysis

Aim: This report proposes using the Hill model to assess the benchmark dose, the 50% lethal dose, the cooperativity and the dissociation constant while analyzing cell viability data using nanomaterials to evaluate the antitumor potential while combined with radiofrequency therapy. Materials & methods: A nanocomposite was synthesized (graphene oxide-polyethyleneimine-gold) and the viability was evaluated using two tumor cell lines, namely LLC-WRC-256 and B16-F10. Results: Our findings demonstrated that while the nanocomposite is biocompatible against the LLC-WRC-256 and B16-F10 cancer cell lines in the absence of radiofrequency, the application of radiofrequency enhances the cell toxicity by orders of magnitude. Conclusion: This result points to prospective studies with the tested cell lines using tumor animal models.

Advent in proteins, nucleic acids, and biological cell membranes functionalized nanocarriers to accomplish active or homologous tumor targeting for smart amalgamated chemotherapy/photo-therapy: A review

Conventional cancer mono-therapeutic approaches including radiotherapy, surgery, and chemotherapy don't always achieve satisfactory outcomes and are frequently associated with significant limitations. Although chemotherapy is a vital intervention, its effectiveness is frequently inadequate and is associated with metastasis, multidrug resistance, off-target effect, and normal cells toxicity. Phototherapies are employed in cancer therapy, encompassing photo-dynamic and photo-thermal therapies which under favorable NIR laser light irradiation initiate the included photosensitizers and photo-thermal agents to generate ROS or thermal heat respectively for cancer cells destruction. Photo-therapy is considered noninvasive, posing no resistance, but it still suffers from several pitfalls like low penetration depth and excessive heat generation affecting neighboring tissues. Improved selectivity and tumor-homing capacity could be attained through surface modulation of nanoparticles with targeting ligands that bind to receptors, which are exclusively overexpressed on cancerous cells. Developing novel modified targeted nanoparticulate platforms integrating different therapeutic modalities like photo-therapy and chemotherapy is a topic of active research. This review aimed to highlight recent advances in proteins, nucleic acids, and biological cell membranes functionalized nanocarriers for smart combinatorial chemotherapy/photo-therapy. Nanocarriers decorated with precise targeting ligands, like aptamers, antibody, and lactoferrin, to achieve active tumor-targeting or camouflaging using various biological cell membrane coating are designed to achieve homologous tumor-targeting.

Intratumor delivery of amino-modified graphene oxide as a multifunctional photothermal agent for efficient antitumor phototherapy

Due to the high selectivity and non-invasive property, phototherapy has attracted increasing attention in the treatment of cancer. Targeted delivery and retention of photoactive agents in tumor tissue is of great significance and importance for safe and efficient phototherapy. Herein, we report a multifunctional nanomaterial photothermal agent, namely amino-modified graphene oxide (AGO) for anti-oral cancer photothermal therapy (PTT). Compared to the parental graphene oxide (GO) which has a negative charge and weak photothermal effect, AGO possesses a positive charge (∼+50 mV) and the significantly enhanced photothermal effect. Positive charge allows AGO to efficiently interact with tumor cells and retain in tumor tissue after intratumor injection. The enhanced photothermal effect allows AGO to achieve the tunable and efficient PTT. In vitro results show that AGO (15 μg/mL) reduces the viability of HSC-3 cells (oral squamous cell carcinoma cell line) to 5% under near infrared (NIR) irradiation (temperature increased to 58.4 °C). In vivo antitumor study shows that intratumor delivery of AGO (200 μg/mouse) has no inhibition effects on tumor growth (454% of initial tumor size) without NIR. With a single dose of NIR irradiation, however, AGO significantly reduces the tumor size to 25% of initial size in 1 of 4 mice, and even induces the complete tumor ablation in 3 of 4 mice. Furthermore, the injected AGO falls off along with the scab after PTT. Our findings indicate that AGO is a potential nano-photothermal agent for tunable, convenient and efficient anticancer PTT.

Graphene-Based Materials in Dental Applications: Antibacterial, Biocompatible, and Bone Regenerative Properties

Graphene-based materials have been shown to have advantageous properties in biomedical and dental applications due to their high mechanical, physiochemical, antibacterial, and stem cell differentiating properties. Although graphene-based materials have displayed appropriate biocompatible properties when used in implant materials for orthopedic applications, little research has been performed to specifically test the biocompatibility of graphene for dental applications. The oral environment, compared to the body, varies greatly and must be considered when evaluating biocompatibility requirements for dental applications. This review will discuss in vitro and in vivo studies that assess graphene's cytotoxicity, antibacterial properties, and cell differentiation ability to evaluate the overall biocompatibility of graphene-based materials for dental applications. Particle shape, size, and concentration were found to be major factors that affected overall biocompatibility of graphene.

Synthesis and characterization of a novel, pH-responsive sustained release nanocarrier using polyethylene glycol, graphene oxide, and natural silk fibroin protein by a green nano emulsification method to enhance cancer treatment

In this study, for the first time, by employing a simple and efficient double nano-emulsification method and using sweet almond oil as the organic phase, polyethylene glycol (PEG)/graphene oxide (GO)/silk fibroin (SF) hydrogel-nanocomposite was synthesized. The aim of the research was to fabricate a biocompatible targeted pH-sensitive sustained release carrier, improve the drug loading capacity and enhance the anticancer effect of doxorubicin (DOX) drug. The obtained values for the entrapment (%EE) and loading efficacy (%LE) were 87.75 ± 0.7 % and 46 ± 1 %, respectively, and these high values were due to the use of GO with a large specific surface area and the electrostatic interaction between the drug and SF. The Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses confirmed the presence of all the components in the nanocomposite and the suitable interaction between them. Based on the results of dynamic light scattering analysis (DLS) and zeta potential analysis, the mean size of the carrier particles and its surface charge were 293.7 nm and -102.9 mV, respectively. The high negative charge was caused by the presence of hydroxyl groups in GO and SF and it caused proper stability of the nanocomposite. The spherical core-shell structure with its homogeneous surface was also observed in the field emission scanning electron microscopy (FE-SEM) image. The cumulative release percentage of the nanocarrier reached 95.75 after 96 h and it is higher in the acidic environment at all times. The results of fitting the release data to the kinetic models suggested that the mechanism of release was dissolution-controlled anomalous at pH 7.4 and diffusion-controlled anomalous at pH 5.4. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry showed an increase in toxicity on MCF-7 cells and improved apoptotic cell death compared to the free drug. Consequently, the findings of this research introduced and confirmed PEG/GO/SF nanocomposite as an attractive novel drug delivery system for pH-sensitive and sustained delivery of chemotherapeutic agents in biomedicine.

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.

Nanomedicine in Clinical Photodynamic Therapy for the Treatment of Brain Tumors

The current treatment for malignant brain tumors includes surgical resection, radiotherapy, and chemotherapy. Nevertheless, the survival rate for patients with glioblastoma multiforme (GBM) with a high grade of malignancy is less than one year. From a clinical point of view, effective treatment of GBM is limited by several challenges. First, the anatomical complexity of the brain influences the extent of resection because a fine balance must be struck between maximal removal of malignant tissue and minimal surgical risk. Second, the central nervous system has a distinct microenvironment that is protected by the blood–brain barrier, restricting systemically delivered drugs from accessing the brain. Additionally, GBM is characterized by high intra-tumor and inter-tumor heterogeneity at cellular and histological levels. This peculiarity of GBM-constituent tissues induces different responses to therapeutic agents, leading to failure of targeted therapies. Unlike surgical resection and radiotherapy, photodynamic therapy (PDT) can treat micro-invasive areas while protecting sensitive brain regions. PDT involves photoactivation of photosensitizers (PSs) that are selectively incorporated into tumor cells. Photo-irradiation activates the PS by transfer of energy, resulting in production of reactive oxygen species to induce cell death. Clinical outcomes of PDT-treated GBM can be advanced in terms of nanomedicine. This review discusses clinical PDT applications of nanomedicine for the treatment of GBM.

Recent progress of graphene oxide-based multifunctional nanomaterials for cancer treatment

Background

In the last decade, graphene oxide-based nanomaterials, such as graphene oxide (GO) and reduced graphene oxide (rGO), have attracted more and more attention in the field of biomedicine. Due to the versatile surface functionalization, ultra-high surface area, and excellent biocompatibility of graphene oxide-based nanomaterials, which hold better promise for potential applications than among other nanomaterials in biomedical fields including drug/gene delivery, biomolecules detection, tissue engineering, especially in cancer treatment.

Results

Here, we review the recent progress of graphene oxide-based multifunctional nanomaterials for cancer treatment. A comprehensive and in-depth depiction of unique property of graphene oxide-based multifunctional nanomaterials is first interpreted, with particular descriptions about the suitability for applying in cancer therapy. Afterward, recently emerging representative applications of graphene oxide-based multifunctional nanomaterials in antitumor therapy, including as an ideal carrier for drugs/genes, phototherapy, and bioimaging, are systematically summarized. Then, the biosafety of the graphene oxide-based multifunctional nanomaterials is reviewed.

Conclusions

Finally, the conclusions and perspectives on further advancing the graphene oxide-based multifunctional nanomaterials toward potential and versatile development for fundamental researches and nanomedicine are proposed.

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e-Graphene: A Computational Platform for the Prediction of Graphene-Based Drug Delivery System by Quantum Genetic Algorithm and Cascade Protocol

Graphene, as a novel category of carbon nanomaterials, has attracted a great attention in the field of drug delivery. Due to its large dual surface area, graphene can efficiently load drug molecules with high capacity via non-covalent interaction without chemical modification of the drugs. Hence, it ignites prevalent interests in developing a new graphene/graphene oxide (GO)-based drug delivery system (GDDS). However, current design of GDDS primarily depends on the prior experimental experience with the trial-and-error method. Thus, it is more appealing to theoretically predict possible GDDS candidates before experiments. Toward this end, we propose to fuse quantum genetic algorithm (QGA) and quantum mechanics (QM)/semi-empirical quantum mechanics (SQM)/force field (FF) to globally search the optimal binding interaction between the graphene/GO and drug in a given GDDS and develop a free computational platform “e-Graphene” to automatically predict/screen potential GDDS candidates. To make this platform more pragmatic for the rapid yet relatively accurate prediction, we further propose a cascade protocol via firstly conducting a fast QGA/FF calculation with fine QGA parameters and automatically passing the best chromosomes from QGA/FF to initialize a higher level QGA/SQM or QGA/QM calculation with coarse QGA parameters (e.g., small populations and short evolution generations). By harnessing this platform and protocol, systematic tests on a typical GDDS containing an anticancer drug SN38 illustrate that high fabrication rates of hydroxyl, epoxy, and carboxyl groups on a pristine graphene model will compromise the stability of GDDS, implying that an appropriate functionalization rate is crucial for the delicate balance between the stability and solubility/biocompatibility of GDDS. Moreover, automatic GDDS screen in the DrugBank database is performed and elicits four potential GDDS candidates with enhanced stability than the commonly tested GDDS containing SN38 from the computational point of view. We hope that this work can provide a useful program and protocol for experimental scientists to rationally design/screen promising GDDS candidates prior to experimental tests.

Multi-Component Hydrogel Beads Incorporated with Reduced Graphene Oxide for pH-Responsive and Controlled Co-Delivery of Multiple Agents

The development of combination therapy has received great attention in recent years because of its potential to achieve higher therapeutic efficacy than that achieved by mono-drug therapy. Carriers for effective and stimuli-responsive co-delivery of multiple agents, however, are highly deficient at the moment. To address this need, this study reports the generation of multi-component hydrogel beads incorporated with reduced graphene oxide (rGO). The beads are prepared by incorporating doxorubicin (DOX)-loaded gelatine (GL) microbeads into hydrogel beads containing rGO and 5-fluorouracil (5-FU). rGO-containing beads are shown to be more effective in inhibiting the growth of MCF-7 cells via the induction of reactive oxygen species (ROS) generation. In addition, the drug release sustainability of the beads is affected by the pH of the release medium, with the release rate increasing in neutral pH but decreasing in the acidic environment. Our beads warrant further development as carriers for pH-responsive and controlled co-delivery of multiple agents.

Recent research progress in the construction of active free radical nanoreactors and their applications in photodynamic therapy

Photodynamic therapy is the most important treatment strategy in free radical therapy. However, tumor microenvironment hypoxia is a key obstacle in PDT. In order to overcome this obstacle, the strategy of in situ production of O₂/radicals by catalytic reaction in solid tumors was proposed. In recent years, it has been found that there are many oxygen-independent carbon-based free radicals that can generate toxic active free radicals under laser irradiation and lead to tumor cell death. Based on the rational design of multifunctional nano-medicine, the active free radical nano-generator has opened up a new way for the highly developed nanotechnology and tumor cooperative therapy to improve the therapeutic effect. In this paper, the research status of active free radical nano-generators, especially reactive oxygen species, including the construction mechanism of active free radical nanomaterials, is reviewed and the application of free radical nano-generators in tumor therapy is emphasized.

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.

Fluorescent hollow mesoporous carbon spheres for drug loading and tumor treatment through 980-nm laser and microwave co-irradiation

Hollow mesoporous particles for drug delivery and cancer therapy have attracted significant attention over recent decades. Here, we develop a simple and highly efficient strategy for preparing fluorescent hollow mesoporous carbon spheres (HMCSs). Compared with typical carbon materials such as fullerene C60, carbon nanotubes, reduced graphene oxide, and carbon nanohorns; HMCSs showed fewer effects on cell cycle distribution and lower toxicity to cells. Ten different drugs were incorporated into the HMCSs, and the maximum loading efficiency reached 42.79 ± 2.7%. Importantly, microwaves were found to improve the photothermal effect generated by HMCSs when combined with 980-nm laser irradiation. The cell killing and tumor growth inhibition efficiencies of HMCSs and drug-loaded HMCSs under co-irradiation with laser and microwaves were significantly improved compared with those under laser irradiation alone. After local administration HMCSs were only distributed in tissue at the injection site. HMCSs showed almost no toxicity in mice after local injection and could be completely removed from the injection site.

Preparation and anti-cancer activity of transferrin/folic acid double-targeted graphene oxide drug delivery system

In this study, a transferrin/folic acid double-targeting graphene oxide drug delivery system loaded with doxorubicin was designed. Graphene oxide was prepared by ultrasound improved Hummers method and was modified with Pluronic F68, folic acid, and transferrin to decrease its toxicity and to allow dual-targeting. The results show that the double target drug delivery system (TFGP*DOX) has good and controllable drug delivery performance with no toxicity. Moreover, TFGP*DOX has a better inhibitory effect on SMMC-7721 cells than does a single target drug delivery system (FGP*DOX). The results of drug release analysis and cell inhibition studies showed that TFGP*DOX has a good sustained release function that can reduce the drug release rate in blood circulation over time and improve the local drug concentration in or near a targeted tumor. Therefore, the drug loading system (TFGP*DOX) has potential application value in the treatment of hepatocellular carcinoma.

Advances in nanomaterials for photodynamic therapy applications: Status and challenges

Photodynamic therapy (PDT), as a non-invasive therapeutic modality that is alternative to radiotherapy and chemotherapy, is extensively investigated for cancer treatments. Although conventional organic photosensitizers (PSs) are still widely used and have achieved great progresses in PDT, the disadvantages such as hydrophobicity, poor stability within PDT environment and low cell/tissue specificity largely limit their clinical applications. Consequently, nano-agents with promising physicochemical and optical properties have emerged as an attractive alternative to overcome these drawbacks of traditional PSs. Herein, the up-to-date advances in the fabrication and fascinating applications of various nanomaterials in PDT have been summarized, including various types of nanoparticles, carbon-based nanomaterials, and two-dimensional nanomaterials, etc. In addition, the current challenges for the clinical use of PDT, and the corresponding strategies to address these issues, as well as future perspectives on further improvement of PDT have also been discussed.

Sulfobetaine methacrylate-functionalized graphene oxide-IR780 nanohybrids aimed at improving breast cancer phototherapy

The application of Graphene Oxide (GO) in cancer photothermal therapy is hindered by its lack of colloidal stability in biologically relevant media and modest Near Infrared (NIR) absorption. In this regard, the colloidal stability of GO has been improved by functionalizing its surface with poly(ethylene glycol) (PEG), which may not be optimal due to the recent reports on PEG immunogenicity. On the other hand, the chemical reduction of GO using hydrazine hydrate has been applied to enhance its photothermal capacity, despite decreasing its cytocompatibility. In this work GO was functionalized with an amphiphilic polymer containing [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) brushes and was loaded with IR780, for the first time, aiming to improve its colloidal stability and phototherapeutic capacity. The attained results revealed that the SBMA-functionalized GO displays a suitable size distribution, neutral surface charge and adequate cytocompatibility. Furthermore, the SBMA-functionalized GO exhibited an improved colloidal stability in biologically relevant media, while its non-SBMA functionalized equivalent promptly precipitated under the same conditions. By loading IR780 into the SBMA-functionalized GO, its NIR absorption increased by 2.7-fold, leading to a 1.2 times higher photothermal heating. In in vitro cell studies, the combination of SBMA-functionalized GO with NIR light only reduced breast cancer cells' viability to 73%. In stark contrast, by combining IR780 loaded SBMA-functionalized GO and NIR radiation, the cancer cells' viability decreased to 20%, hence confirming the potential of this nanomaterial for cancer photothermal therapy.

IR780 loaded SBMA-coated GO displayed an improved colloidal stability in biologically relevant media and an enhanced photothermal capacity.

An electrochemical sensing platform amplified with a Au@Ag nanoparticle-decorated three-dimensional N-doped graphene aerogel for ultrasensitive determination of baicalein

A novel electrochemical method for highly sensitive determination of baicalein was developed with Au@Ag/3DNGA as signal amplifier.

Aminated Graphene Oxide as a Potential New Therapy for Colorectal Cancer

Nanotechnology-based drug delivery systems for cancer therapy are the topic of interest for many researchers and scientists. Graphene oxide (GO) and its derivates are among the most extensively studied delivery systems of this type. The increased surface area, elevated loading capacity, and aptitude for surface functionalization together with the ability to induce reactive oxygen species make GO a promising tool for the development of novel anticancer therapies. Moreover, GO nanoparticles not only function as effective drug carriers but also have the potential to exert their own inhibitory effects on tumour cells. Recent results show that the functionalization of GO with different functional groups, namely, with amine groups, leads to increased reactivity of the nanoparticles. The last steers different hypotheses for the mechanisms through which this functionalization of GO could potentially lead to improved anticancer capacity. In this research, we have evaluated the potential of amine-functionalized graphene oxide nanoparticles (GO-NH₂) as new molecules for colorectal cancer therapy. For the purpose, we have assessed the impact of aminated graphene oxide (GO) sheets on the viability of colon cancer cells, their potential to generate ROS, and their potential to influence cellular proliferation and survival. In order to elucidate their mechanism of action on the cellular systems, we have probed their genotoxic and cytostatic properties and compared them to pristine GO. Our results revealed that both GO samples (pristine and aminated) were composed of few-layer sheets with different particle sizes, zeta potential, and surface characteristics. Furthermore, we have detected increased cyto- and genotoxicity of the aminated GO nanoparticles following 24-hour exposure on Colon 26 cells. The last leads us to conclude that exposure of cancer cells to GO, namely, aminated GO, can significantly contribute to cancer cell killing by enhancing the cytotoxicity effect exerted through the induction of ROS, subsequent DNA damage, and apoptosis.

Stimuli-responsive graphene-incorporated multifunctional chitosan for drug delivery applications: a review

INTRODUCTION

Recently, the use of chitosan (CS) in the drug delivery has reached an acceptable maturity. Graphene-based drug delivery is also increasing rapidly due to its unique physical, mechanical, chemical, and electrical properties. Therefore, the combination of CS and graphene can provide a promising carrier for the loading and controlled release of therapeutic agents.

AREAS COVERED

In this review, we will outline the advantages of this new drug delivery system (DDS) in association with CS and graphene alone and will list the various forms of these carriers, which have been studied in recent years as DDSs. Finally, we will discuss the application of this hybrid composite in other fields.

EXPERT OPINION

The introducing the GO amends the mechanical characteristics of CS, which is a major problem in the use of CS-based carriers in drug delivery due to burst release in a CS-based controlled release system through the poor mechanical strength of CS. Many related research on this area are still not fully unstated and occasionally they seem inconsistent in spite of the intent to be complementary. Therefore, a sensitive review may be needed to understand the role of graphene in CS/graphene carriers for future drug delivery applications.