Graphene quantum dot formulation for cancer imaging and redox-based drug delivery

Recent advances in biomedical applications of carbon and graphene quantum dots: A review

The carbon-based nanostructures have led to the development of theranostic nanoplatforms for simultaneous diagnosis and therapy due to their effective cell membrane-penetration ability, low degree of cytotoxicity, excellent pore volume, substantial chemical stability, and reactive surface. In the last few years, extensive efforts were made to design multifunctional nanoplatform strategies based on carbon nanostructures, involving multimodal imaging, controlled drug release capabilities, sensing in vitro, efficient drug loading capacity, and therapy. Carbon and graphene quantum dots (CQDs and GQDs) were the recent entrants, contingently being assessed for drug delivery and bioimaging. With the advancements, these quantum dots have ignited remarkable research interest and are now widely evaluated for diagnosis, bioimaging, sensing, and drug delivery applications. The last decade has witnessed their remarkable electrical, optical, and biocompatible properties since their inception. It is presumed that both of them have high potential as drug carriers and would serve as the next generation of approaches to address numerous unresolved therapeutic challenges. This review examined the recent advances of CQD and GQD based drug delivery applications, challenges, and future perspectives to pave the way for further studies in the future.

Photocleavable DNA Nanotube-Based Dual-Amplified Resonance Rayleigh Scattering System for MicroRNA Detection Incorporating Molecular Computing-Cascaded Keypad Lock Functionality

Cascade molecular events in complex systems are of vital importance for enhancing molecular diagnosis and information processing. However, the conversion of a cascaded biosensing system into a multilayer encrypted molecular keypad lock remains a significant challenge in the development of molecular logic devices. In this study, we present a photocleavable DNA nanotube-based dual-amplified resonance Rayleigh scattering (RRS) system for detecting microRNA-126 (miR-126). The cascading dual-amplification biosensing system provides a multilayer-encrypted prototype with the functionality of a molecular computing cascade keypad lock. RRS signals were greatly amplified by using photocleavable DNA nanotubes and enzyme-assisted strand displacement amplification (SDA). In the presence of miR-126, enzyme-assisted SDA produced numerous identical nucleotide fragments as the target, which were then specifically attached to magnetic beads through the DNA nanotube by using a Y-shaped DNA scaffold. Upon ultraviolet irradiation, the DNA nanotube was released into the solution, resulting in an increase in the intensity of the RRS signal. This strategy demonstrated a low limit of detection (0.16 fM) and a wide dynamic range (1 fM to 1 nM) for miR-126. Impressively, the enzyme-assisted SDA offers a molecular computing model for generating the target pool, which serves as the input element for unlocking the system. By cascading the molecular computing process, we successfully constructed a molecular keypad lock with a multilevel authentication technique. The proposed system holds great potential for applications in molecular diagnosis and information security, indicating significant value in integrating molecular circuits for intelligent sensing.

Recent Advances in NIR or X-ray Excited Persistent Luminescent Materials for Deep Bioimaging

Due to their persistent luminescence, persistent luminescent (PersL) materials have attracted great interest. In the biomedical field, the use of persistent luminescent nanoparticles (PLNPs) eliminates the need for continuous in situ excitation, thereby avoiding interference from tissue autofluorescence and significantly improving the signal-to-noise ratio (SNR). Although persistent luminescence materials can emit light continuously, the luminescence intensity of small-sized nanoparticles in vivo decays quickly. Early persistent luminescent nanoparticles were mostly excited by ultraviolet (UV) or visible light and were administered for imaging purposes through ex vivo charging followed by injection into the body. Limited by the low in vivo penetration depth, UV light cannot secondary charge PLNPs that have decayed in vivo, and visible light does not penetrate deep enough to reach deep tissues, which greatly limits the imaging time of persistent luminescent materials. In order to address this issue, the development of PLNPs that can be activated by light sources with superior tissue penetration capabilities is essential. Near-infrared (NIR) light and X-rays are widely recognized as ideal excitation sources, making persistent luminescent materials stimulated by these two sources a prominent area of research in recent years. This review describes NIR and X-ray excitable persistent luminescence materials and their recent advances in bioimaging.

In Vitro Prostate Cancer Treatment via CRISPR-Cas9 Gene Editing Facilitated by Polyethyleneimine-Derived Graphene Quantum Dots

CRISPR-Cas9 is a programmable gene editing tool with a promising potential for cancer gene therapy. This therapeutic function is enabled in the present work via the non-covalent delivery of CRISPR ribonucleic protein (RNP) by cationic glucosamine/PEI-derived graphene quantum dots (PEI-GQD) that aid in overcoming physiological barriers and tracking genes of interest. PEI-GQD/RNP complex targeting the TP53 mutation overexpressed in ~50% of cancers successfully produces its double-stranded breaks in solution and in PC3 prostate cancer cells. Restoring this cancer "suicide" gene can promote cellular repair pathways and lead to cancer cell apoptosis. Its repair to the healthy form performed by simultaneous PEI-GQD delivery of CRISPR RNP and a gene repair template leads to a successful therapeutic outcome: 40% apoptotic cancer cell death, while having no effect on non-cancerous HeK293 cells. The translocation of PEI-GQD/RNP complex into PC3 cell cytoplasm is tracked via GQD intrinsic fluorescence, while EGFP-tagged RNP is detected in the cell nucleus, showing the successful detachment of the gene editing tool upon internalization. Using GQDs as non-viral delivery and imaging agents for CRISPR-Cas9 RNP sets the stage for image-guided cancer-specific gene therapy.

Doped Graphene Quantum Dots as Biocompatible Radical Scavenging Agents

Oxidative stress is proven to be a leading factor in a multitude of adverse conditions, from Alzheimer's disease to cancer. Thus, developing effective radical scavenging agents to eliminate reactive oxygen species (ROS) driving many oxidative processes has become critical. In addition to conventional antioxidants, nanoscale structures and metal-organic complexes have recently shown promising potential for radical scavenging. To design an optimal nanoscale ROS scavenging agent, we have synthesized ten types of biocompatible graphene quantum dots (GQDs) augmented with various metal dopants. The radical scavenging abilities of these novel metal-doped GQD structures were, for the first time, assessed via the DPPH, KMnO4, and RHB (Rhodamine B protectant) assays. While all metal-doped GQDs consistently demonstrate antioxidant properties higher than the undoped cores, aluminum-doped GQDs exhibit 60-95% radical scavenging ability of ascorbic acid positive control. Tm-doped GQDs match the radical scavenging properties of ascorbic acid in the KMnO4 assay. All doped GQD structures possess fluorescence imaging capabilities that enable their tracking in vitro, ensuring their successful cellular internalization. Given such multifunctionality, biocompatible doped GQD antioxidants can become prospective candidates for multimodal therapeutics, including the reduction of ROS with concomitant imaging and therapeutic delivery to cancer tumors.

Cancer Therapeutic siRNA Delivery and Imaging by Nitrogen- and Neodymium-Doped Graphene Quantum Dots

While small interfering RNA (siRNA) technology has become a powerful tool that can enable cancer-specific gene therapy, its translation to the clinic is still hampered by the inability of the genes alone to cell transfection, poor siRNA stability in blood, and the lack of delivery tracking capabilities. Recently, graphene quantum dots (GQDs) have emerged as a novel platform allowing targeted drug delivery and fluorescence image tracking in visible and near-infrared regions. These capabilities can aid in overcoming primary obstacles to siRNA therapeutics. Here, for the first time, we utilize biocompatible nitrogen- and neodymium-doped graphene quantum dots (NGQDs and Nd-NGQDs, respectively) for the delivery of Kirsten rat sarcoma virus (KRAS) and epidermal growth factor receptor (EGFR) siRNA effective against a variety of cancer types. GQDs loaded with siRNA noncovalently facilitate successful siRNA transfection into HeLa cells, confirmed by confocal fluorescence microscopy at biocompatible GQD concentrations of 375 μg/mL. While the GQD platform provides visible fluorescence tracking, Nd doping enables deeper-tissue near-infrared fluorescence imaging suitable for both in vitro and in vivo applications. The therapeutic efficacy of the GQD/siRNA complex is verified by successful protein knockdown in HeLa cells at nanomolar siEGFR and siKRAS concentrations. A range of GQD/siRNA loading ratios and payloads are tested to ultimately provide substantial inhibition of protein expression down to 31-45%, comparable with conventional Lipofectamine-mediated delivery. This demonstrates the promising potential of GQDs for the nontoxic delivery of siRNA and genes in general, complemented by multiwavelength image tracking.

Automated Approach to In Vitro Image-Guided Photothermal Therapy with Top-Down and Bottom-Up-Synthesized Graphene Quantum Dots

Graphene-based materials have been the subject of interest for photothermal therapy due to their high light-to-heat conversion efficiency. Based on recent studies, graphene quantum dots (GQDs) are expected to possess advantageous photothermal properties and facilitate fluorescence image-tracking in the visible and near-infrared (NIR), while surpassing other graphene-based materials in their biocompatibility. Several GQD structures including reduced graphene quantum dots (RGQDs) derived from reduced graphene oxide via top-down oxidation and hyaluronic acid graphene quantum dots (HGQDs) hydrothermally bottom-up synthesized from molecular hyaluronic acid were employed to test these capabilities in the present work. These GQDs possess substantial NIR absorption and fluorescence throughout the visible and NIR beneficial for in vivo imaging while being biocompatible at up to 1.7 mg/mL concentrations. In aqueous suspensions, RGQDs and HGQDs irradiated with a low power (0.9 W/cm2) 808 nm NIR laser facilitate a temperature increase up to 47.0 °C, which is sufficient for cancer tumor ablation. In vitro photothermal experiments sampling multiple conditions directly in the 96-well plate were performed using an automated simultaneous irradiation/measurement system developed on the basis of a 3D printer. In this study, HGQDs and RGQDs facilitated the heating of HeLa cancer cells up to 54.5 °C, leading to the drastic inhibition of cell viability from over 80% down to 22.9%. GQD's fluorescence in the visible and NIR traces their successful internalization into HeLa cells maximized at 20 h suggesting both extracellular and intracellular photothermal treatment capabilities. The combination of the photothermal and imaging modalities tested in vitro makes the GQDs developed in this work prospective agents for cancer theragnostics.

Recent advances of polymer based nanosystems in cancer management

Cancer is still one of the leading causes of death worldwide. Nanotechnology, particularly nanoparticle-based platforms, is at the leading edge of current cancer management research. Polymer-based nanosystems have piqued the interest of researchers owing to their many benefits over other conventional drug delivery systems. Polymers derived from both natural and synthetic sources have various biomedical applications due to unique qualities like porosity, mechanical strength, biocompatibility, and biodegradability. Polymers such as poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), and polyethylene glycol (PEG) have been approved by the USFDA and are being researched for drug delivery applications. They have been reported to be potential carriers for drug loading and are used in theranostic applications. In this review, we have primarily focused on the aforementioned polymers and their conjugates. In addition, the therapeutic and diagnostic implications of polymer-based nanosystems have been briefly reviewed. Furthermore, the safety of the developed polymeric formulations is crucial, and we have discussed their biocompatibility in detail. This article also discusses recent developments in block co-polymer-based nanosystems for cancer treatment. The review ends with the challenges of clinical translation of polymer-based nanosystems in drug delivery for cancer therapy.

Facile and scalable synthesis of un-doped, doped and co-doped graphene quantum dots: a comparative study on their impact for environmental applications

In recent years, graphene quantum dots (GQDs) received huge attention due to their unique properties and potential applicability in different area. Here, we report simple and facile method for the synthesis of GQDs and their functionalization by doping and co-doping using different heteroatom under the optimized conditions. The doping and co-doping of GQDs using boron and nitrogen have been confirmed by FTIR and TEM. The UV-visible and fluorescence techniques have been used to study the optical properties and stability of functionalized GQDs. Further, the screening for enhancement of quantum yields of all GQDs were performed with fluorescence and UV-visible spectra under the optimized conditions. The average QY was obtained as 16.0%, 83.6%, 18.2% and 29.6% for GQDs, B-GQDs, N-GQDs and B,N-GQDs, respectively. The sensor was used to determine paraoxon in water samples. The LOD was observed to be 1.0 × 10^-4 M with linearity range of 0.001 to 0.1 M. The RSD was calculated for the developed B,N-GQDs based sensor and observed to be 2.99% with the regression coefficient as 0.997. All the doped, co-doped and un-doped GQDs possess remarkable properties as a fluorescent probe.

High reactive oxygen species produced from fluorescence carbon dots for anticancer and photodynamic therapies: A review

High-photoluminescence carbon dots (CDs) were synthesized from various sources and various methods using two approaches, namely bottom up and top down, with emission-dependent excitation wavelength. Electronic transition from the higher-occupied molecular orbital (HOMO) state to the lowest-unoccupied molecular orbital(LUMO) state, surface defect states, wider excitation spectrum, higher quantum yield, efficient energy transfer, and element doping affected the fluorescence properties of CDs. Using 102 references listed in this review, the authors studied the relationship between fluorescence mechanism and reactive oxygen species (ROS) produced for photodynamic therapy (PDT) and materials anticancer applications. We described how the radical atom or ROS work as anticancer therapy and PDT and described the chemical reaction of high-resolution fluorescence CDs. We summarized experimental techniques that are used for producing CDs and discussed their characteristics. Finally, conclusions and future prospects in this field are also discussed. The important characteristics of CD-based design for high ROS may usher in new prospects and challenges for high efficiency and stability of PDT and anticancer therapy. In conclusion, we have provided perspectives and challenges of the future development of CD s.

Dual-Mode Fluorescence/Ultrasound Imaging with Biocompatible Metal-Doped Graphene Quantum Dots

Sonography offers many advantages over standard methods of diagnostic imaging due to its non-invasiveness, substantial tissue penetration depth, and low cost. The benefits of ultrasound imaging call for the development of ultrasound-trackable drug delivery vehicles that can address a variety of therapeutic targets. One disadvantage of the technique is the lack of high-precision imaging, which can be circumvented by complementing ultrasound contrast agents with visible and, especially, near-infrared (NIR) fluorophores. In this work, we, for the first time, develop a variety of lightly metal-doped (iron oxide, silver, thulium, neodymium, cerium oxide, cerium chloride, and molybdenum disulfide) nitrogen-containing graphene quantum dots (NGQDs) that demonstrate high-contrast properties in the ultrasound brightness mode and exhibit visible and/or near-infrared fluorescence imaging capabilities. NGQDs synthesized from glucosamine precursors with only a few percent metal doping do not introduce additional toxicity in vitro, yielding over 80% cell viability up to 2 mg/mL doses. Their small (<50 nm) sizes warrant effective cell internalization, while oxygen-containing surface functional groups decorating their surfaces render NGQDs water soluble and allow for the attachment of therapeutics and targeting agents. Utilizing visible and/or NIR fluorescence, we demonstrate that metal-doped NGQDs experience maximum accumulation within the HEK-293 cells 6-12 h after treatment. The successful 10-fold ultrasound signal enhancement is observed at 0.5-1.6 mg/mL for most metal-doped NGQDs in the vascular phantom, agarose gel, and animal tissue. A combination of non-invasive ultrasound imaging with capabilities of high-precision fluorescence tracking makes these metal-doped NGQDs a viable agent for a variety of theragnostic applications.

Detection of Pancreatic Cancer miRNA with Biocompatible Nitrogen-Doped Graphene Quantum Dots

Early-stage pancreatic cancer remains challenging to detect, leading to a poor five-year patient survival rate. This obstacle necessitates the development of early detection approaches based on novel technologies and materials. In this work, the presence of a specific pancreatic cancer-derived miRNA (pre-miR-132) is detected using the fluorescence properties of biocompatible nitrogen-doped graphene quantum dots (NGQDs) synthesized using a bottom-up approach from a single glucosamine precursor. The sensor platform is comprised of slightly positively charged (1.14 ± 0.36 mV) NGQDs bound via π-π stacking and/or electrostatic interactions to the negatively charged (-22.4 ± 6.00 mV) bait ssDNA; together, they form a complex with a 20 nm average size. The NGQDs' fluorescence distinguishes specific single-stranded DNA sequences due to bait-target complementarity, discriminating them from random control sequences with sensitivity in the micromolar range. Furthermore, this targetability can also detect the stem and loop portions of pre-miR-132, adding to the practicality of the biosensor. This non-invasive approach allows cancer-specific miRNA detection to facilitate early diagnosis of various forms of cancer.

Respiratory exposure to graphene quantum dots causes fibrotic effects on lung, liver and kidney of mice

Graphene quantum dots (GQDs), as a novel graphene-based nanoparticle, presented a bright prospect in fields of biomedicine due to their excellent optical property. However, the biosafety assessment of GQDs is far behind their rapid development, which could restrict their wilder applications. This study focused on the potential adverse effects of two kinds of promising GQDs, i.e. nitrogen-doping graphene quantum dots (N-GQDs) and amino-modified graphene quantum dot (A-GQDs) on primary target organs of GNMs, including lung, liver and kidney. The intranasal instillation used here was to imitate the respiratory exposure of GQDs that is a commonly exposure route of GQDs in the environment. Although no severe damages associated with general health occurred in mice treated with GQDs, the fibrosis evidenced by statistically significant increases in the area of collagen I and TGF-ß1 and p-Smad3 expressions were observed in the lung, liver and kidney tissues. Interestingly, the fibrotic effect induced by GQDs could be effectively alleviated by a ferroptosis-specific inhibitor, which demonstrated a close relationship of fibrosis and ferroptosis. This study not only provides new insights on the toxicity mechanisms of GQDs, but also offers some efficient ways to control toxicity of GQDs, like dosage threshold and small molecular drugs.

Nanocarrier cancer therapeutics with functional stimuli-responsive mechanisms

Presently, nanocarriers (NCs) have gained huge attention for their structural ability, good biocompatibility, and biodegradability. The development of effective NCs with stimuli-responsive properties has acquired a huge interest among scientists. When developing drug delivery NCs, the fundamental goal is to tackle the delivery-related problems associated with standard chemotherapy and to carry medicines to the intended sites of action while avoiding undesirable side effects. These nanocarriers were able of delivering drugs to tumors through regulating their pH, temperature, enzyme responsiveness. With the use of nanocarriers, chemotherapeutic drugs could be supplied to tumors more accurately that can equally encapsulate and deliver them. Material carriers for chemotherapeutic medicines are discussed in this review keeping in viewpoint of the structural properties and targeting methods that make these carriers more therapeutically effective, in addition to metabolic pathways triggered by drug-loaded NCs. Largely, the development of NCs countering to endogenous and exogenous stimuli in tumor regions and understanding of mechanisms would encourage the progress for tumor therapy and precision diagnosis in future.

Nitrogen-doped graphene quantum dots induce ferroptosis through disrupting calcium homeostasis in microglia

Background

Along with the wild applications of nitrogen-doped graphene quantum dots (N-GQDs) in the fields of biomedicine and neuroscience, their increasing exposure to the public and potential biosafety problem has gained more and more attention. Unfortunately, the understanding of adverse effects of N-GQDs in the central nervous system (CNS), considered as an important target of nanomaterials, is still limited.

Results

After we found that N-GQDs caused cell death, neuroinflammation and microglial activation in the hippocampus of mice through the ferroptosis pathway, microglia was used to assess the molecular mechanisms of N-GQDs inducing ferroptosis because it could be the primary target damaged by N-GQDs in the CNS. The microarray data suggested the participation of calcium signaling pathway in the ferroptosis induced by N-GQDs. In microglial BV2 cells, when the calcium content above the homeostatic level caused by N-GQDs was reversed, the number of cell death, ferroptosis alternations and excessive inflammatory cytokines release were all alleviated. Two calcium channels of L-type voltage-gated calcium channels (L-VGCCs) in plasma membrane and ryanodine receptor (RyR) in endoplasmic reticulum (ER) took part in N-GQDs inducing cytosolic calcium overload. L-VGCCs and RyR calcium channels were also involved in promoting the excess iron influx and triggering ER stress response, respectively, which both exert excessive ROS generation and result in the ferroptosis and inflammation in BV2 cells.

Conclusion

N-GQDs exposure caused ferroptosis and inflammatory responses in hippocampus of mice and cultured microglia through activating two calcium channels to disrupt intracellular calcium homeostasis. The findings not only posted an alert for biomedical applications of N-GQDs, but also highlighted an insight into mechanism researches of GQDs inducing multiple types of cell death in brain tumor therapy in the future.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00464-z.

Hyaluronic Acid-Conjugated Carbon Nanomaterials for Enhanced Tumour Targeting Ability

Hyaluronic acid (HA) has been implemented for chemo and photothermal therapy to target tumour cells overexpressing the CD44+ receptor. HA-targeting hybrid systems allows carbon nanomaterial (CNM) carriers to efficiently deliver anticancer drugs, such as doxorubicin and gemcitabine, to the tumour sites. Carbon nanotubes (CNTs), graphene, graphene oxide (GO), and graphene quantum dots (GQDs) are grouped for a detailed review of the novel nanocomposites for cancer therapy. Some CNMs proved to be more successful than others in terms of stability and effectiveness at removing relative tumour volume. While the literature has been focused primarily on the CNTs and GO, other CNMs such as carbon nano-onions (CNOs) proved quite promising for targeted drug delivery using HA. Near-infrared laser photoablation is also reviewed as a primary method of cancer therapy-it can be used alone or in conjunction with chemotherapy to achieve promising chemo-photothermal therapy protocols. This review aims to give a background into HA and why it is a successful cancer-targeting component of current CNM-based drug delivery systems.

Carbon-Based Materials in Photodynamic and Photothermal Therapies Applied to Tumor Destruction

Within phototherapy, a grand challenge in clinical cancer treatments is to develop a simple, cost-effective, and biocompatible approach to treat this disease using ultra-low doses of light. Carbon-based materials (CBM), such as graphene oxide (GO), reduced GO (r-GO), graphene quantum dots (GQDs), and carbon dots (C-DOTs), are rapidly emerging as a new class of therapeutic materials against cancer. This review summarizes the progress made in recent years regarding the applications of CBM in photodynamic (PDT) and photothermal (PTT) therapies for tumor destruction. The current understanding of the performance of modified CBM, hybrids and composites, is also addressed. This approach seeks to achieve an enhanced antitumor action by improving and modulating the properties of CBM to treat various types of cancer. Metal oxides, organic molecules, biopolymers, therapeutic drugs, among others, have been combined with CBM to treat cancer by PDT, PTT, or synergistic therapies.

A Deep Learning Analysis Reveals Nitrogen-Doped Graphene Quantum Dots Damage Neurons of Nematode Caenorhabditis elegans

Along with the rapidly increasing applications of nitrogen-doped graphene quantum dots (N-GQDs) in the field of biomedicine, the exposure of N-GQDs undoubtedly pose a risk to the health of human beings, especially in the nervous system. In view of the lack of data from in vivo studies, this study used the nematode Caenorhabditis elegans (C. elegans), which has become a valuable animal model in nanotoxicological studies due to its multiple advantages, to undertake a bio-safety assessment of N-GQDs in the nervous system with the assistance of a deep learning model. The findings suggested that accumulated N-GQDs in the nematodes' bodies damaged their normal behavior in a dose- and time-dependent manner, and the impairments of the nervous system were obviously severe when the exposure dosages were above 100 μg/mL. When assessing the morphological changes of neurons caused by N-GQDs, a quantitative image-based analysis based on a deep neural network algorithm (YOLACT) was used because traditional image-based analysis is labor-intensive and limited to qualitative evaluation. The quantitative results indicated that N-GQDs damaged dopaminergic and glutamatergic neurons, which are involved in the neurotoxic effects of N-GQDs in the nematode C. elegans. This study not only suggests a fast and economic C. elegans model to undertake the risk assessment of nanomaterials in the nervous system, but also provides a valuable deep learning approach to quantitatively track subtle morphological changes of neurons at an unbiased level in a nanotoxicological study using C. elegans.

A convergent synthetic platform for dual anticancer drugs functionalized by reduced graphene nanocomposite delivery for hepatocellular cancer

Hepatocellular carcinoma (HCC) is widespread cancer with a high degree of morbidity and mortality in individuals worldwide and a serious concern for its resistance to present chemotherapy drugs. In this investigation, the combination of cisplatin (CPT) and metformin (MET) to kill the HepG2 and caco-2 cells was developed into a new pH-responding magnetic nanocomposite based on reduced graphene oxide. Polyhydroxyethyl methacrylic (PHEA) was then linked employing grafting from approach to the reduced graphene oxide by ATRP polymerization (Fe₃O₄@rGO-G-PSEA). FT-IR, SEM, XRD, DLS, and TGA analyses evaluated physicochemical characteristics of the nanocomposite. In addition, the cellular uptake property of the nanocomposites was examined by the HepG2 cells. The outcomes of cell viability results indicate that the nanoparticles loaded with MET&CPT showed the lowest concentration rate of HepG2 and Caco-2 cells compared to the drug-loaded single nanocomposite groups and free drugs. The histological analysis has demonstrated relatively safe and does not produce different stress such as swelling and inflammation of the mice organs. Our results show the enhancement in cytotoxicity in HepG2 and Cocoa-2 cells by MET and CPT graphene oxide-based nanocomposite by promoting apoptotic response. Moreover, Fe₃O₄@rGO-G-PSEA showed potent in vivo antitumor efficacy but showed no adverse toxicity to normal tissues. Together, this study can provide insight into how surface embellishment may tune these nanocomposites' tumor specificity and provide the basis for developing anticancer efficacy.

Graphene and its derivatives: understanding the main chemical and medicinal chemistry roles for biomedical applications

Over the past few years, there has been a growing potential use of graphene and its derivatives in several biomedical areas, such as drug delivery systems, biosensors, and imaging systems, especially for having excellent optical, electronic, thermal, and mechanical properties. Therefore, nanomaterials in the graphene family have shown promising results in several areas of science. The different physicochemical properties of graphene and its derivatives guide its biocompatibility and toxicity. Hence, further studies to explain the interactions of these nanomaterials with biological systems are fundamental. This review has shown the applicability of the graphene family in several biomedical modalities, with particular attention for cancer therapy and diagnosis, as a potent theranostic. This ability is derivative from the considerable number of forms that the graphene family can assume. The graphene-based materials biodistribution profile, clearance, toxicity, and cytotoxicity, interacting with biological systems, are discussed here, focusing on its synthesis methodology, physicochemical properties, and production quality. Despite the growing increase in the bioavailability and toxicity studies of graphene and its derivatives, there is still much to be unveiled to develop safe and effective formulations.

Graphic abstract