Selectivity-Enhanced Electroreduction of CO2 to CO at Novel Ru-Linked-GO Nanohybrids: the Role of Nanoarchitecture

Recently, global-scale efforts have been conducted for the electroreduction of CO2 as a potentially beneficial pathway for the conversion of greenhouse gases to useful chemicals and renewable fuels. This study focuses on the development of selective and sustainable electrocatalysts for the reduction of aqueous CO2 to CO. A RuIIcomplex [Ru(tptz)(ACN)Cl2] (RCMP) (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine, ACN = acetonitrile) was prepared as a molecular electrocatalyst for the CO2 reduction reaction in an aqueous solution. Density functional theory-calculated frontier molecular orbitals suggested that the tptz ligand plays a key role in dictating the electrocatalytic reactions. The RCMP electrocatalyst was grafted onto the graphene oxide (GO) surface both noncovalently (GO/RCMP) and covalently (GO-RCMP). The field emission scanning electron microscopy and elemental distribution analyses revealed the homogeneous distribution of the complex onto the GO sheet. The photoluminescence spectra confirmed accelerated charge-transfer in both nanohybrids. Compared to the bare complex, the GO-RCMP and GO/RCMP nanohybrids showed enhanced electrocatalytic activity, achieving >95% and 90% Faradaic efficiencies for CO production at more positive onset potentials, respectively. The GO-RCMP nanohybrid demonstrated outstanding electrocatalytic activity with a current of ∼84 μA. The study offers a perspective on outer- and inner-sphere electron-transfer mechanisms for electrochemical energy conversion systems.

Pristine/folate-functionalized graphene oxide as two intrinsically radioiodinated nano-theranostics: self/dual in vivo targeting comparative study

Background

Nanomedicine offers great potentials for theranostic studies via providing higher efficacy and safety levels. This work aimed to develop and evaluate a new nanoplatform as a tumor theranostic probe.

Results

Carboxyl-functionalized graphene oxide nanosheets (FGO) was well synthesized from graphite powder and then conjugated with folic acid to act as a targeted nano-probe. Full characterization and in vitro cytotoxicity evaluation were conducted; besides, in vivo bio-evaluation was attained via intrinsic radioiodination approach in both normal and tumor-bearing Albino mice. The results indicated that FGO as well as conjugated graphene oxide nanosheets (CGO) are comparatively non-toxic to normal cells even at higher concentrations. Pharmacokinetics of FGO and CGO showed intensive and selective uptake in the tumor sites where CGO showed high T/NT of 7.27 that was 4 folds of FGO at 1 h post injection. Additionally, radioiodinated-CGO (ICGO) had declared a superior prominence over the previously published tumor targeted GO radiotracers regarding the physicochemical properties pertaining ability and tumor accumulation behavior.

Conclusions

In conclusion, ICGO can be used as a selective tumor targeting agent for cancer theranosis with aid of I-131 that has a maximum beta and gamma energies of 606.3 and 364.5 keV, respectively.

Fabrication of glucose bioelectrochemical sensor based on Au@Pd core-shell supported by carboxylated graphene oxide

The study presents a novel electrochemical glucose biosensor based on glucose oxidase (GOx) immobilized on Au@Pd core-shell nanoparticles supported on carboxylated graphene oxide (cGO). The immobilization of GOx was achieved by cross-linking the chitosan biopolymer (CS) including Au@Pd/cGO and glutaraldehyde (GA) on a glassy carbon electrode. The analytical performance of GCE/Au@Pd/cGO-CS/GA/GOx was investigated using amperometry. The biosensor had fast response time (5.2 ± 0.9 s), a satisfactory linear determination range between 2.0 × 10^-5 and 4.2 × 10^-3 M, and limit of detection of 10.4 μM. The apparent Michaelis-Menten constant (K_app) was calculated as 3.04 mM. The fabricated biosensor also exhibited good repeatability, reproducibility, and storage stability. No interfering signals from dopamine, uric acid, ascorbic acid, paracetamol, folic acid, mannose, sucrose, and fructose were observed. The large electroactive surface area of carboxylated graphene oxide is a promising candidate for sensor preparation.

Fabrication of octenyl succinic anhydride starch grafted with folic acid and its loading potential for doxorubicin hydrochloride

In this study, octenyl succinic anhydride (OSA) starch with different folic acid (FA) grafting time was prepared and the degree of FA substitution at different grafting time was determined. The results of XPS quantitatively reflected the surface elemental composition of OSA starch grafted with FA. FTIR spectra further confirmed the successful introduction of FA on OSA starch granules. SEM images showed that the surface roughness of OSA starch granules was more obvious with higher FA grafting time. The particle size, zeta potential, and swelling properties were determined to study the effect of FA on the structure of OSA starch. TGA indicated that FA effectively enhanced the thermal stability of OSA starch at high temperature. The crystalline form of the OSA starch gradually transformed from A type to a hybrid A and V-type with the progress of FA grafting reaction. In addition, the anti-digestive properties of OSA starch were enhanced after grafting FA. Using doxorubicin hydrochloride (DOX) as the model drug, the loading efficiency of OSA starch grafted with FA for DOX reached 87.71 %. These results provide novel insights into OSA starch grafted with FA as potential strategy for loading DOX.

Advances in analysis of pharmaceuticals by using graphene-based sensors

Safe and effective use of drugs relies on proper pharmaceutical analysis. Graphene has been extensively used to construct sensors for this purpose. Over the years, a large variety of pharmaceutical sensors have been developed from graphene or its derivatives. This articles reviews the current status of sensor development from graphene and its derivatives, and discusses the use of graphene-based sensors in pharmaceutical analysis. It is hoped that this article cannot only offer a snapshot of recent advances in the fabrication and use of graphene-based sensors, but can also provide insights into future engineering and optimization of the sensors for effective pharmaceutical analysis.

Poly (vinyl alcohol)/chitosan/polyethylene glycol-assembled graphene oxide bio-nanocomposites as a prosperous candidate for biomedical applications and drug/food packaging industry

The graphene oxide (GO) nanoplates and polyethylene glycol-decorated GO (GO-PEG nano-hybrid) were synthesized and characterized by FTIR, Raman, XRD, AFM, FE-SEM-EDAX and MTT assay. Obtained results confirmed the graphite oxidation and also assembly of PEG upon GO plates. The MTT assay indicated that GO-PEG nanohybrid enhanced biocompatibility to cells compared to the GO. The GO-PEG nanohybrid was introduced to the polyvinyl alcohol/chitosan carbohydrate (PVA/CS) blends. The bio-nanocomposite were prepared by simple casting method. The GO-PEG nanohybrids demonstrated a significant role in improving thermal, mechanical and antibacterial properties. Accordingly, bio-nanocomposites containing modified GO (PVA/CS/GO-PEG) exhibited higher glass transition temperature (Tg), Young's modulus, tensile strength, elongation at break and antibacterial properties than nanocomposites containing pure GO (PVA/CS/GO). The biodegradation outcomes indicated that the highest weight loss and degradability is related to the bio-nanocomposite containing modified GO (PVA/CS/GO-PEG), which was also confirmed by FE-SEM micrographs. Therefore, PVA/CS/GO-PEG bio-nanocomposites can be a suitable candidate for biomedical applications (tissue engineering, wound dressing) and food-drug packaging industry.

Silencing of Pyruvate Kinase M2 via a Metal-Organic Framework Based Theranostic Gene Nanomedicine for Triple-Negative Breast Cancer Therapy

Triple-negative breast cancer (TNBC) is typically associated with poor prognosis due to its only partial response to chemotherapy and lack of clinically established targeted therapies coupled with an aggressive disease course. Aerobic glycolysis is a hallmark of reprogrammed metabolic activity in cancer cells, which can be repressed by small-interfering RNA (siRNA). However, the lack of effective carriers to deliver vulnerable siRNA restricts the clinical potentials of glycolysis-based gene therapy for TNBC. Herein, we develop a tumor-targeted, biomimetic manganese dioxide (MnO₂)-shrouded metal-organic framework (MOF) based nanomedicine to deliver siRNA against pyruvate kinase muscle isozyme M2 (siPKM2), wherein PKM2 is a rate-limiting enzyme in glycolysis, to inhibit the reprogrammed glycolysis of TNBC. This MOF-based genetic nanomedicine shows excellent monodispersity and stability and protects siPKM2 against degradation by nucleases. The nanomedicine not only substantially blocks the glycolytic pathway but also improves intracellular hypoxia in TNBC cells, with a resultant O₂-enhanced anticancer effect. In the mice orthotopic TNBC model, the nanomedicine shows a remarkable therapeutic effect. Meanwhile, the Mn²⁺ ions released from acid microenvironment-responsive MnO₂ enable in vivo monitoring of the therapeutic process with magnetic resonance imaging (MRI). Our study shows great promise with this MRI-visible MOF-based nanomedicine for treating TNBC by inhibition of glycolysis via the RNA interference.

Functionalized graphene oxide as a vehicle for targeted drug delivery and bioimaging applications

Graphene oxide (GO) has attracted tremendous attention as a most promising nanomaterial among the carbon family since it emerged as a polynomial functional tool with rational applications in diverse fields such as biomedical engineering, electrocatalysis, biosensing, energy conversion, and storage devices. Despite having certain limitations due to its irreversible aggregation performance owing largely to the strong van der Waals interactions, efforts have been made to smartly engineer its surface chemistry for realistic multimodal applications. The use of such GO-based engineered devices has increased rapidly in the last few years, principally due to its excellent properties, such as huge surface area, honeycomb-like structure allowing vacant interstitial space to accommodate compounds, sp2 hybridized carbon, improved biocompatibility and cell surface penetration due to electronic interactions. Amongst multifaceted GO dynamics, in this review, attempts are made to discuss the advanced applications of GO or graphene-based materials (GBNs) in the biomedical field involving drug or therapeutic gene delivery, dual drug or drug-gene combination targeting, special delivery of drug cocktails to the brain, stimuli-responsive release of molecular payloads, and Janus-structured smart applications for polar-nonpolar combination drug loading followed by targeting together with smart bioimaging approaches. In addition, the advantages of duel-drug delivery systems are discussed in detail. We also discuss various electronic mechanisms, and detailed surface engineering to meet microcosmic criteria for its utilization, various novel implementations of engineered GO as mentioned above, together with discussions of its inevitable toxicity or disadvantages. We hope that the target audience, belonging to biomedical engineering, pharmaceutical or material science fields, may acquire relevant information from this review which may help them design future studies in this field.

CuS/rGO-PEG Nanocomposites for Photothermal Bonding of PMMA-Based Plastic Lab-on-a-Chip

We developed copper sulfide (CuS)/reduced graphene oxide (rGO)-poly (ethylene glycol) (PEG) nanocomposites for photothermal bonding of a polymethyl methacrylate (PMMA)-based plastic lab-on-a-chip. The noncontact photothermal bonding of PMMA-based plastic labs-on-chip plays an important role in improving the stability and adhesion at a high-temperature as well as minimizing the solution leakage from microchannels when connecting two microfluidic devices. The CuS/rGO-PEG nanocomposites were used to bond a PMMA-based plastic lab-on-a-chip in a short time with a high photothermal effect by a near-infrared (NIR) laser irradiation. After the thermal bonding process, a gap was not generated in the PMMA-based plastic lab-on-a-chip due to the low viscosity and density of the CuS/rGO-PEG nanocomposites. We also evaluated the physical and mechanical properties after the thermal bonding process, showing that there was no solution leakage in PMMA-based plastic lab-on-a-chip during polymerase chain reaction (PCR) thermal cycles. Therefore, the CuS/rGO-PEG nanocomposite could be a potentially useful nanomaterial for non-contact photothermal bonding between the interfaces of plastic module lab-on-a-chip.

Targeted antimicrobial peptide delivery in vivo to tumor with near infrared photoactivated mesoporous silica nanoparticles

Antimicrobial peptide PA-C1b (chensinin-1b conjugated with palmitic acid) showed potent anticancer activity with no obvious hemolytic activity, which made it a potential agent for treating cancers. However, after in vivo administration, peptides can be degraded by proteases because there is no effective protection. In this study, a tumor-targeting photoresponsive antimicrobial peptide delivery system was developed, and the peptide PA-C1b labeled with the dye sulfo-cyanine7 (Cy7) was loaded into mesoporous silica nanoparticles (MSNs). The final MSN@Cy7-PA-C1b nanoparticles were wrapped by graphene oxide (GO), and then folic acid was conjugated to the surface of the MSNs for targeting purposes. The final MSN@Cy7-PA-C1b@FA-GO nanoparticles were constructed to allow light-mediated peptide release and folate receptor-targeted cancer therapy. The Cy7 dye serves as a real-time indicator, and GO acts as a gatekeeper to prevent leakage of the loaded peptides in the absence of near-infrared light irradiation. Upon light irradiation, the GO wrapping detaches, and the photoresponsive peptide delivery system works well both in in vitro cell experiments and during in vivo administration in mouse tumor experiments. The construction of the MSN@Cy7-PA-C1b@FA-GO platform provides a novel approach to deliver antimicrobial peptides in vivo for the treatment of infections by pathogenic microorganisms and cancers.

rGO nanomaterial-mediated cancer targeting and photothermal therapy in a microfluidic co-culture platform

We developed the microfluidic co-culture platform to study photothermal therapy applications. We conjugated folic acid (FA) to target breast cancer cells using reduced graphene oxide (rGO)-based functional nanomaterials. To characterize the structure of rGO-based nanomaterials, we analyzed the molecular spectrum using UV-visible and Fourier-transform infrared spectroscopy (FT-IR). We demonstrated the effect of rGO-FA-based nanomaterials on photothermal therapy of breast cancer cells in the microfluidic co-culture platform. From the microfluidic co-culture platform with breast cancer cells and human umbilical vein endothelial cells (HUVECs), we observed that the viability of breast cancer cells treated with rGO-FA-based functional nanomaterials was significantly decreased after near-infrared (NIR) laser irradiation. Therefore, this microfluidic co-culture platform could be a potentially powerful tool for studying cancer cell targeting and photothermal therapy.

A Review of Theranostics Applications and Toxicities of Carbon Nanomaterials

BACKGROUND

In the last few years, the use of modified Carbon Nanomaterials (CNMs) for theranostics (therapeutic and diagnosis) applications is a new and rapidly growing area in pharmacy and medical fields. Owing to this, their specific physicochemical behaviors like high stability, drug loading, surface area to volume ratio, with low toxicity and immunogenicity are mainly responsible to be considered those as smart nanomaterials.

OBJECTIVES

This review describes the different dimensions of carbon-based nanocarriers including 0-D fullerene, 1-D Carbon Nanotubes (CNTs), and 2-D graphene and Graphene Oxide (GO) and their surface modification with different biocompatible and biodegradable molecules via covalent or non-covalent functionalization. The major focus of this article is on the different theranostics applications of CNMs like targeted drugs and genes delivery, photodynamic therapy, photothermal therapy, bioimaging, and biosensing. The therapeutic efficacy of drugs could be enhanced by delivering them directly on a specific site using different targeted ligands such as vitamins, peptide, carbohydrates, proteins, etc. A section of the article also discusses the toxicity of the CNMs to the living systems.

CONCLUSIONS

In brief, this review article discusses the numerous theranostics applications and toxicities of CNMs.

Generation of tumor spheroids using a droplet-based microfluidic device for photothermal therapy

Despite their simplicity, monolayer cell cultures are not able to accurately predict drug behavior in vivo due to their inability to accurately mimic cell-cell and cell-matrix interactions. In contrast, cell spheroids are able to reproduce these interactions and thus would be a viable tool for testing drug behavior. However, the generation of homogenous and reproducible cell spheroids on a large scale is a labor intensive and slow process compared to monolayer cell cultures. Here, we present a droplet-based microfluidic device for the automated, large-scale generation of homogenous cell spheroids in a uniform manner. Using the microfluidic system, the size of the spheroids can be tuned to between 100 and 130 μm with generation frequencies of 70 Hz. We demonstrated the photothermal therapy (PTT) application of brain tumor spheroids generated by the microfluidic device using a reduced graphene oxide-branched polyethyleneimine-polyethylene glycol (rGO-BPEI-PEG) nanocomposite as the PTT agent. Furthermore, we generated uniformly sized neural stem cell (NSC)-derived neurospheres in the droplet-based microfluidic device. We also confirmed that the neurites were regulated by neurotoxins. Therefore, this droplet-based microfluidic device could be a powerful tool for photothermal therapy and drug screening applications.

Polymer-Graphene Nanoassemblies and their Applications in Cancer Theranostics

BACKGROUND AND OBJECTIVE

Graphene-based nanomaterials have received increasing attention due to their unique physical-chemical properties including two-dimensional planar structure, large surface area, chemical and mechanical stability, superconductivity and good biocompatibility. On the other hand, graphene-based nanomaterials have been explored as theranostics agents, the combination of therapeutics and diagnostics. In recent years, grafting hydrophilic polymer moieties have been introduced as an efficient approach to improve the properties of graphene-based nanomaterials and obtain new nanoassemblies for cancer therapy.

METHODS AND RESULTS

This review would illustrate biodistribution, cellular uptake and toxicity of polymergraphene nanoassemblies and summarize part of successes achieved in cancer treatment using such nanoassemblies.

CONCLUSION

The observations showed successful targeting functionality of the polymer-GO conjugations and demonstrated a reduction of the side effects of anti-cancer drugs for normal tissues.

Applications of graphene oxide in case of nanomedicines and nanocarriers for biomolecules: review study

In this Review article, recent progress in matter of graphene oxide (GO) synthesis and its functionalization via a vast range of materials, including small molecules, polymers, and biomolecules, were reported and systematically summarized in order to overcome the inherent drawbacks of GO nanocarriers and thereby make these nanocarriers suitable for delivering chemotherapeutic agents, genes, and short interfering RNAs. Briefly, this work describes current strategies for the large scale production of GO and modification of graphene-based nanocarriers surfaces through practical chemical approaches, improving their biocompatibility and declining their toxicity. It also describes the most relevant cases of study suitable to demonstrate the role of graphene and graphene derivatives (GD) as nanocarrier for anti-cancer drugs and genes (e.g. miRNAs). Moreover, the controlled release mechanisms within the cell compartments and blood pH for targeted therapeutics release in the acidic environment of tumor cells or in intracellular compartments are mentioned and explored.

Au-aided reduced graphene oxide-based nanohybrids for photo-chemotherapy

Graphene-based nanomaterials show great potential in photo-chemotherapy, but their photo-thermal effect is not very satisfactory. Herein, we presented a facile and low-cost strategy to grow Au clusters on the reduced graphene oxide (rGO) sheets aiming to improve photothermal effect. Au clusters with low-concentration was directly conjugated on the surface of rGO by electrostatic forces. To improve its biocompatibility, 3‑(3‑phenylureido) propanoic acid (PPA)-PEG (PPEG) had been introduced as biodegradable backbone to form rGO/Au/PPEG nanohybrids via π-π accumulation. The obtained rGO-based nanohybrids showed excellent biocompatibility, stability, low cytotoxicity, and enhanced photo-thermal conversion efficiency. To verify the synergistic photo-chemotherapy, doxorubicin (DOX) as a drug model had been loaded in rGO/Au/PPEG nanohybrids. The results indicated that rGO/Au/PPEG/DOX exhibited synergistic therapeutic efficacy compared with single chemotherapy or photothermal therapy, endowing this designed rGO-based nanohybrids with great potential for cancer treatments.

Design and Development of Graphene Oxide Nanoparticle/Chitosan Hybrids Showing pH-Sensitive Surface Charge-Reversible Ability for Efficient Intracellular Doxorubicin Delivery

A novel graphene oxide nanoparticle (GON)-based drug delivery system containing GONs as carriers of anticancer drugs and chitosan/dimethylmaleic anhydride-modified chitosan (CS/CS-DMMA) as surface charge-reversible shells is fabricated via the classic self-assembly of the deprotonated carboxyl of GONs and the protonated amine of the CS backbone by electrostatic interaction, and CS-DMMA serves as the outmost layer. In this GON-based drug delivery system, the GON cores as desired carriers might adsorb doxorubicin hydrochloride (DOX) via the π-π stacking interaction between the large π conjugated structures of GO and the aromatic structure of DOX. Meanwhile, the chitosan-based polyelectrolyte shells served as a smart protection screen to evade the premature release of the as-loaded DOX in normal extracellular condition, and then, the release of DOX was accelerated because of the detachment of chitosan coating at low pH. Furthermore, the re-exposure of amino groups after hydrolysis of CS-DMMA endowed the drug delivery system with positive surface charge by taking advantage of the pH difference between physiological conditions and the tumor microenvironment to enhance the cellular uptake. Then, the pH-dependent site-specific drug release was realized. The in vitro investigations confirmed that these promising GON/CS/CS-DMMA hybrids with the charge-reversible character possessed various merits including excellent encapsulation efficiency, high stability under physiological conditions, enhanced cellular uptake by HepG2 cells, and tunable intracellular chemotherapeutic agent release profiles, proving its capability as an intelligent anticancer agent nanocarrier with enhanced therapeutic effects. This smart GON/CS/CS-DMMA vehicle with the surface charge-reversible character may be used as a significant drug delivery system for cancer treatment.

Modality switching between therapy and imaging based on the excitation wavelength dependence of dual-function agents in folic acid-conjugated graphene oxides

Owing to its near infrared (NIR) absorption, graphene oxide (GO) is promising for both photothermal (PT) therapy and multiphoton (MP) imaging. Novel therapy/imaging modality switching is proposed here based on the selected excitation wavelength of femtosecond (FS) laser. GO-based destruction of cancer cells is demonstrated when the laser power of 800-nm-wavelength FS laser is increased above 7 mW. However, GO-based imaging is mainly monitored without damaging the sample when using 1200-nm wavelength FS laser in the same laser power range. Folic acid (FA) conjugated graphene oxide (FA-GO) was synthesized for selective cancer cell targeting. Dual-function FA-GO-based cancer cell targeting agents were experimentally optimized to enable therapy/imaging modality switching.

Synthesis of novel cyclodextrin-modified reduced graphene oxide composites by a simple hydrothermal method

Cyclodextrin (β-CD)-functionalized reduced graphene oxide was successfully synthesized by a simple hydrothermal method, followed by conjugating with polyethylene glycol (PEG) and folic acid (FA). Microscopic and spectroscopic techniques were used to characterize the nanocomposites. Photothermal experiments showed that β-CD-functionalized reduced graphene oxide exhibited higher photothermal conversion efficiency in the near infrared region than reduced graphene oxide functionalized with other molecules under the same conditions. Cytotoxicity experiments indicated that rGO@CD@PEG@FA possessed good biocompatibility even at high concentration. When doxorubicin (DOX) was loaded on the rGO@CD@PEG@FA nanocomposite, it showed the stimulative effect of heat, pH response, and sustained drug release. Cytotoxicity experiments also confirmed the targeted effect and high efficiency of the combined therapy. The findings of the present study provide an ideal drug delivery system for malignant cancer therapy due to the advanced synergistic chemo-photothermal targeted therapy and good drug release properties.

The rGO@CD@PEG@FA nanocomposite showed the stimulative effect of heat, pH response, and sustained drug release for cancer therapy

Biomolecular engineering for nanobio/bionanotechnology

Biomolecular engineering can be used to purposefully manipulate biomolecules, such as peptides, proteins, nucleic acids and lipids, within the framework of the relations among their structures, functions and properties, as well as their applicability to such areas as developing novel biomaterials, biosensing, bioimaging, and clinical diagnostics and therapeutics. Nanotechnology can also be used to design and tune the sizes, shapes, properties and functionality of nanomaterials. As such, there are considerable overlaps between nanotechnology and biomolecular engineering, in that both are concerned with the structure and behavior of materials on the nanometer scale or smaller. Therefore, in combination with nanotechnology, biomolecular engineering is expected to open up new fields of nanobio/bionanotechnology and to contribute to the development of novel nanobiomaterials, nanobiodevices and nanobiosystems. This review highlights recent studies using engineered biological molecules (e.g., oligonucleotides, peptides, proteins, enzymes, polysaccharides, lipids, biological cofactors and ligands) combined with functional nanomaterials in nanobio/bionanotechnology applications, including therapeutics, diagnostics, biosensing, bioanalysis and biocatalysts. Furthermore, this review focuses on five areas of recent advances in biomolecular engineering: (a) nucleic acid engineering, (b) gene engineering, (c) protein engineering, (d) chemical and enzymatic conjugation technologies, and (e) linker engineering. Precisely engineered nanobiomaterials, nanobiodevices and nanobiosystems are anticipated to emerge as next-generation platforms for bioelectronics, biosensors, biocatalysts, molecular imaging modalities, biological actuators, and biomedical applications.

Pegylated folate and peptide-decorated graphene oxide nanovehicle for in vivo targeted delivery of anticancer drugs and therapeutic self-monitoring

This work reports a graphene oxide-based nanovehicle with conjugation of pegylated folate for targeted delivery of anticancer drugs and fluorescein-labeled peptide for therapeutic self-monitoring in vitro and in vivo. The nanovehicle could absorb hydrophobic and aromatic drug molecules with high loading capacity and efficiency of more than 1.7 mg mg(-1) and 90%, respectively. MTT and flow cytometric assays demonstrated that the drug-loaded nanovehicle could specifically transport and release the drugs into the folate receptor high-expressed cancer cells, which ensured a high therapeutic efficiency to cancer cells and prevented the injury to normal cells. Moreover, confocal fluorescence imaging confirmed that the drug-induced cancer cell death could be visualized with the light-up fluorescence of fluorescein activated by caspase-3. The targeted delivery of drug and self-evaluation of therapeutic efficacy were further successfully realized by living imaging in tumor-bearing mice, which broaden the applications of this theranostic system in vivo and may offer new opportunities for precise cancer treatment.

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.

A tumor-targeting drug delivery system based on cyclic NGR-modified, combretastatin A4-loaded, functionalized graphene oxide nanosheets

Graphene oxide has shown great potential in drug delivery.

Investigation of biological cell–small molecule interactions with a gold surface plasmon resonance sensor using a laser scanning confocal imaging-surface plasmon resonance system

In our work, we investigated the interactions between a small molecule, folic acid, and biological cells through the interaction of folic acid and folate receptors using a laser scanning confocal imaging-surface plasmon resonance (LSCI-SPR) system.

Non-covalent modification of graphene oxide nanocomposites with chitosan/dextran and its application in drug delivery

Graphene oxide nanosheets non-covalent functionalized with chitosan/dextran was successfully developed via LbL self-assembly technique for anti-cancer drug delivery application.

Fluorescent graphene oxide via polymer grafting: an efficient nanocarrier for both hydrophilic and hydrophobic drugs

Functionalized graphene-based drug delivery vehicles have conquered a significant position because functionalization improves its biocompatibility and stability in cell medium, leaving sufficient graphitic basal plane for drug loading through π-π stacking. In this study, poly(N-isopropylacrylamide) (PNIPAM) is covalently grafted from the surface of graphene oxide (GO) via a facile, eco-friendly and an easy procedure of free radical polymerization (FRP) using ammonium persulfate initiator. Various spectroscopic and microscopic studies confirm the successful grafting of PNIPAM from GO surface. PNIPAM-grafted GO (GPNM) exhibits enhanced thermal stability, improved dispersibility both in aqueous and cell medium, and better biocompatibility and cell viability compared to GO. Interestingly, GPNM displays an exciting fluorescence property in aqueous medium, which is a hike of intensity at 36 °C due to the lower critical solution temperature (LCST) of PNIPAM chains (32 °C). Moreover both hydrophilic (doxorubicin (DOX)) and hydrophobic (indomethacin (IMC)) drugs loaded on the surface of GPNM hybrid exhibits its efficacy as an efficient carrier for both types of drugs. Cellular uptakes of free DOX and DOX-loaded GPNM (GPNM-DOX) are evidenced both from optical and fluorescence imaging of live cells, and the efficiency of drug is significantly improved in the loaded system. The release of DOX from GPNM-DOX was achieved at pH 4, relevant to the environment of cancer cells. The pH-triggered release of hydrophobic drug was also studied using UV-vis spectroscopy via alginate encapsulation, showing a great enhancement at pH = 7.4. The IMC is also found to be released by human serum albumin using dialysis technique. The GPNM nanomaterial shows the property of simultaneous loading of DOX and IMC as well as pH-triggered simultaneous release of both of the drugs.

cRGDyK-modified camretastain A4-loaded graphene oxide nanosheets for targeted anticancer drug delivery

Functionalized graphene oxide (CGO–cRGDyK/POLO) nanosheets were designed and developed for targeted drug delivery to integrin expression.

Hydrophobic-polymer-grafted graphene oxide nanosheets as an easily separable adsorbent for the removal of tetrabromobisphenol A

Hydrophobic polymer brushes have been grafted from graphene oxide nanosheets (GO) via the facile surface-initiated redox radical polymerization of tert-butyl acrylate (tBA) from the GO with cerium ammonium nitrate (CAN) as an oxidant. After the hydrophobic surface modification, the poly(tert-butyl acrylate) (PtBA)-grafted graphene oxide nanosheets (GO-PtBA) could still be dispersed in water because of the remaining oxygen-containing groups but deposited within 40 min. The feature makes it an easily separable adsorbent for environmental pollutants. For example, tetrabromobisphenol A (TBBPA) could be removed from aqueous solution via hydrogen bonds (between hydroxyl groups of TBBPA and hydroxyl and carboxyl groups of GO) and π-π interactions (between the benzene ring of TBBPA and GO), with an adsorption capacity of 22.2 mg g(-1) at pH 7.0. The TBBPA-adsorbed GO-PtBA could be deposited completely within 30 min, and the adsorbed TBBPA could be easily desorbed with ethanol, demonstrating its good recyclability.