Fluorinated graphene oxide; a new multimodal material for biological applications

Chemistry of Graphene Derivatives: Synthesis, Applications, and Perspectives

The chemistry of graphene and its derivatives is one of the hottest topics of current material science research. The derivatisation of graphene is based on various approaches, and to date functionalization with halogens, hydrogen, various functional groups containing oxygen, sulfur, nitrogen, phosphorus, boron, and several other elements have been reported. Most of these functionalizations are based on sp³ hybridization of carbon atoms in the graphene skeleton, which means the formation of out-of-plane covalent bonds. Several elements were also reported for substitutional modification of graphene, where the carbon atoms are substituted with atoms like nitrogen, boron, and several others. From tens of functional groups, for only two of them were reported full functionalization of graphene skeleton and formation of its stoichiometric counterparts, fluorographene and hydrogenated graphene. The functionalization of graphene is crucial for most of its applications including energy storage and conversion devices, electronic and optic applications, composites, and many others.

Fluorescence turn-off Ag/fluorinated graphene composites with high NIR absorption for effective killing of cancer cells and bacteria

This study establishes FGO–Ag as a novel fluorescence “turn-off” nanocarrier with good targeting efficiency and high NIR absorption and drug loading; it also demonstrates its application in antibacterial and cancer chemo-photothermal treatments.

Fluorinated graphene as an anticancer nanocarrier: an experimental and DFT study

Both experimental and theoretical research was conducted to explore the performance of fluorinated graphene as a novel anticancer nanocarrier, and we also reported its first application in cancer chemo-photothermal therapy.

Nano-sized paramagnetic and fluorescent fluorinated carbon fiber with high NIR absorbance for cancer chemo-photothermal therapy

We report a novel strategy to synthesize nano-sized, water-soluble and functionalized fluorinated carbon fiber oxide with high fluorescence, paramagnetism and NIR absorption for cancer chemo-photothermal therapy.

Photoluminescent F-doped carbon dots prepared by ring-opening reaction for gene delivery and cell imaging

Carbon dots (CDs) are photoluminescent nanoparticles with distinctive properties, having great potential in nano-biomaterial systems such as gene/drug delivery vectors and cell imaging agents.

Coverage-dependent essential properties of halogenated graphene: A DFT study

The significant halogenation effects on the essential properties of graphene are investigated by the first-principles method. The geometric structures, electronic properties, and magnetic configurations are greatly diversified under the various halogen adsorptions. Fluorination, with the strong multi-orbital chemical bondings, can create the buckled graphene structure, while the other halogenations do not change the planar s bonding in the presence of single-orbital hybridization. Electronic structures consist of the carbon-, adatom- and (carbon, adatom)-dominated energy bands. All halogenated graphenes belong to holedoped metals except that fluorinated systems are middle-gap semiconductors at sufficiently high concentration. Moreover, the metallic ferromagnetism is revealed in certain adatom distributions. The unusual hybridization-induced features are clearly evidenced in many van Hove singularities of density of states. The structure- and adatom-enriched essential properties are compared with the measured results, and potential applications are also discussed.

Chemistry, properties, and applications of fluorographene

Fluorographene, formally a two-dimensional stoichiometric graphene derivative, attracted remarkable attention of the scientific community due to its extraordinary physical and chemical properties. We overview the strategies for the preparation of fluorinated graphene derivatives, based on top-down and bottom-up approaches. The physical and chemical properties of fluorographene, which is considered as one of the thinnest insulators with a wide electronic band gap, are presented. Special attention is paid to the rapidly developing chemistry of fluorographene, which was advanced in the last few years. The unusually high reactivity of fluorographene, which can be chemically considered perfluorinated hydrocarbon, enables facile and scalable access to a wide portfolio of graphene derivatives, such as graphene acid, cyanographene and allyl-graphene. Finally, we summarize the so far reported applications of fluorographene and fluorinated graphenes, spanning from sensing and bioimaging to separation, electronics and energy technologies.

An In Vitro Study of the Photodynamic Effectiveness of GO-Ag Nanocomposites against Human Breast Cancer Cells

Graphene-based materials have garnered significant attention because of their versatile bioapplications and extraordinary properties. Graphene oxide (GO) is an extremely oxidized form of graphene accompanied by the functional groups of oxygen on its surface. GO is an outstanding platform on which to pacify silver nanoparticles (Ag NPs), which gives rise to the graphene oxide-silver nanoparticle (GO-Ag) nanocomposite. In this experimental study, the toxicity of graphene oxide-silver (GO-Ag) nanocomposites was assessed in an in vitro human breast cancer model to optimize the parameters of photodynamic therapy. GO-Ag was prepared using the hydrothermal method, and characterization was done by X-ray diffraction, field-emission scanning electron microscope (FE-SEM), transmission Electron Microscopy (TEM), energy dispersive X-rays Analysis (EDAX), atomic force microscopy and ultraviolet-visible spectroscopy. The experiments were done both with laser exposure, as well as in darkness, to examine the phototoxicity and cytotoxicity of the nanocomposites. The cytotoxicity of the GO-Ag was confirmed via a methyl-thiazole-tetrazolium (MTT) assay and intracellular reactive oxygen species production analysis. The phototoxic effect explored the dose-dependent decrease in the cell viability, as well as provoked cell death via apoptosis. An enormously significant escalation of ¹O₂ in the samples when exposed to daylight was perceived. Statistical analysis was performed on the experimental results to confirm the worth and clarity of the results, with p-values < 0.05 selected as significant. These outcomes suggest that GO-Ag nanocomposites could serve as potential candidates for targeted breast cancer therapy.

Evaluation of the Photothermal Properties of a Reduced Graphene Oxide/Arginine Nanostructure for Near-Infrared Absorption

Strong near-infrared (NIR) absorption of reduced graphene oxide (rGO) make this material a candidate for photothermal therapy. The use of rGO has been limited by low stability in aqueous media due to the lack of surface hydrophilic groups. We report synthesis of a novel form of reduced graphene-arginine (rGO-Arg) as a nanoprobe. Introduction of Arg to the surface of rGO not only increases the stability in aqueous solutions but also increases cancer cell uptake. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) images are recorded to characterize the morphology of rGO-Arg. Fourier transform infrared (FTIR), X-ray photoelectron spectra (XPS), Raman, and UV-vis spectroscopy are utilized to analyze the physiochemical properties of rGO-Arg. Interaction of rGO-Arg with 808 nm laser light has been evaluated by measuring the absorption cross section in response to periodically modulated intensity to minimize artifacts arising from lateral thermal diffusion with a material scattering matched to a low scattering optical standard. Cell toxicity and cellular uptake by MD-MB-231 cell lines provide supporting data for the potential application of rGO-Arg for photothermal therapy. Absorption cross-section results suggest rGO-Arg is an excellent NIR absorber that is 3.2 times stronger in comparison to GO.

Fluorine Functionalized Graphene Quantum Dots as Inhibitor against hIAPP Amyloid Aggregation

Fibrillar deposits of the human islet amyloid polypeptide (hIAPP) are considered as a root of Type II diabetes mellitus. Fluorinated graphene quantum dots (FGQDs) are new carbon nanomaterials with unique physicochemical properties containing highly electronegative F atoms. Herein we report a single step synthesis method of FGQDs with an inhibitory effect on aggregation and cytotoxicity of hIAPP in vitro. Highly fluorescent and water dispersible FGQDs, less than 3 nm in size, were synthesized by the microwave-assisted hydrothermal method. Efficient inhibition capability of FGQDs to amyloid aggregation was demonstrated. The morphologies of hIAPP aggregates were observed to change from the entangled long fibrils to short thin fibrils and amorphous aggregates in the presence of FGQDs. In thioflavin T fluorescence analysis, inhibited aggregation with prolonged lag time and reduced fluorescence intensity at equilibrium were observed when hIAPP was incubated together with FGQDs. Circular dichroism spectrum results reveal that FGQDs could inhibit conformational transition of the peptide from native structure to β-sheets. FGQDs could also rescue the cytotoxicity of INS-1 cells induced by hIAPP in a dose dependent manner. This study could be beneficial for design and preparation of inhibitors for amyloids, which is important for prevention and treatment of amyloidosis.

Paramagnetic Properties of Metal-Free Boron-Doped Graphene Quantum Dots and Their Application for Safe Magnetic Resonance Imaging

A boron-doped graphene quantum dot (B-GQD) as a metal-free multimodal contrast agent (CA) for safe magnetic resonance imaging and fluorescence imaging is reported. In vivo T1 -weighted magnetic resonance images show that B-GQDs induce significant contrast enhancement on the heart, liver, spleen, and kidney, and sustain for more than 1 h, about 10 times longer than Gd-based CAs currently used in clinic.

Towards stoichiometric analogues of graphene: graphane, fluorographene, graphol, graphene acid and others

Stoichiometric derivatives of graphene, having well-defined chemical structure and well-defined chemical bonds, are of a great interest to the 2D materials research.

Probing plasma fluorinated graphene via spectromicroscopy

The graphene fluorination using CF₄ and SF₆ plasma is investigated by combining spectroscopy and microscopy techniques.

Preparation and properties of a novel graphene fluoroxide/polyimide nanocomposite film with a low dielectric constant

A novel graphene fluoroxide/polyimide nanocomposite film with a low dielectric constant is prepared with excellent mechanical and thermal properties.

Fluorinated carbon fiber as a novel nanocarrier for cancer chemo-photothermal therapy

We report a novel strategy to synthesize nanosized water-soluble fluorinated carbon fiber oxide (FCO) that doubles as an effective photothermal agent and a high cargo payload platform for an anticancer drug.

Hierarchically porous fluorine-doped graphene nanosheets as efficient metal-free electrocatalyst for oxygen reduction in gas diffusion electrode

Here a simple yet cost-effective strategy is developed to fabricate fluorine-doped graphene nanosheets, we successfully, prepared fluorine doped graphene via thermal treatment of graphene oxide and NaF (sodium fluoride) in H₂SO₄ solution phase. Importantly, the electrocatalytic activity for oxygen reduction reaction (ORR) is carefully evaluated for fluorographene (FG). None-metal graphene electro catalysts for the ORR are attractive for their high activity and economic advantages. A significant research effort is also directed to the so-called "metal-free" ORR on heteroatom-doped graphene surfaces. The electrochemical activity of F-RGO in the ORR is investigated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) using rotating disk electrode (RDE) measurements on glassy carbon and on gas diffusion electrode (GDE) based carbon paper in oxygen saturated alkaline aqueous solutions.

Toxicity of graphene-family nanoparticles: a general review of the origins and mechanisms

Due to their unique physicochemical properties, graphene-family nanomaterials (GFNs) are widely used in many fields, especially in biomedical applications. Currently, many studies have investigated the biocompatibility and toxicity of GFNs in vivo and in intro. Generally, GFNs may exert different degrees of toxicity in animals or cell models by following with different administration routes and penetrating through physiological barriers, subsequently being distributed in tissues or located in cells, eventually being excreted out of the bodies. This review collects studies on the toxic effects of GFNs in several organs and cell models. We also point out that various factors determine the toxicity of GFNs including the lateral size, surface structure, functionalization, charge, impurities, aggregations, and corona effect ect. In addition, several typical mechanisms underlying GFN toxicity have been revealed, for instance, physical destruction, oxidative stress, DNA damage, inflammatory response, apoptosis, autophagy, and necrosis. In these mechanisms, (toll-like receptors-) TLR-, transforming growth factor β- (TGF-β-) and tumor necrosis factor-alpha (TNF-α) dependent-pathways are involved in the signalling pathway network, and oxidative stress plays a crucial role in these pathways. In this review, we summarize the available information on regulating factors and the mechanisms of GFNs toxicity, and propose some challenges and suggestions for further investigations of GFNs, with the aim of completing the toxicology mechanisms, and providing suggestions to improve the biological safety of GFNs and facilitate their wide application.

Two-Dimensional Fluorinated Graphene: Synthesis, Structures, Properties and Applications

Fluorinated graphene, an up-rising member of the graphene family, combines a two-dimensional layer-structure, a wide bandgap, and high stability and attracts significant attention because of its unique nanostructure and carbon-fluorine bonds. Here, we give an extensive review of recent progress on synthetic methods and C-F bonding; additionally, we present the optical, electrical and electronic properties of fluorinated graphene and its electrochemical/biological applications. Fluorinated graphene exhibits various types of C-F bonds (covalent, semi-ionic, and ionic bonds), tunable F/C ratios, and different configurations controlled by synthetic methods including direct fluorination and exfoliation methods. The relationship between the types/amounts of C-F bonds and specific properties, such as opened bandgap, high thermal and chemical stability, dispersibility, semiconducting/insulating nature, magnetic, self-lubricating and mechanical properties and thermal conductivity, is discussed comprehensively. By optimizing the C-F bonding character and F/C ratios, fluorinated graphene can be utilized for energy conversion and storage devices, bioapplications, electrochemical sensors and amphiphobicity. Based on current progress, we propose potential problems of fluorinated graphene as well as the future challenge on the synthetic methods and C-F bonding character. This review will provide guidance for controlling C-F bonds, developing fluorine-related effects and promoting the application of fluorinated graphene.

Superfluorinated PEI Derivative Coupled with (99m) Tc for ASGPR Targeted (19) F MRI/SPECT/PA Tri-Modality Imaging

Fluorinated polyethylenimine derivative labeled with radionuclide (99m) Tc is developed as a (19) F MRI/SPECT/PA multifunctional imaging agent with good asialoglycoprotein receptors (ASGPR)-targeting ability. This multifunctional agent is safe and suitable for (19) F MRI/SPECT/PA imaging and has the potential to detect hepatic diseases and to assess liver function, which provide powerful support for the development of personalized and precision medicine.

Graphene Meets Microbubbles: A Superior Contrast Agent for Photoacoustic Imaging

Coupling graphene with a soft polymer surface offers the possibility to build hybrid constructs with new electrical, optical, and mechanical properties. However, the low reactivity of graphene is a hurdle in the synthesis of such systems which is often bypassed by oxidizing its carbon planar structure. However, the defects introduced with this process jeopardize the properties of graphene. In this paper we present a different approach, applicable to many different polymer surfaces, which uses surfactant assisted ultrasonication to exfoliate, and simultaneously suspend, graphene in water in its intact form. Tethering pristine graphene sheets to the surfaces is accomplished by using suitable reactive functional groups of the surfactant scaffold. We focused on applying this approach to the fabrication of a hybrid system, made of pristine graphene tethered to poly(vinyl alcohol) based microbubbles (PVA MBs), designed for enhancing photoacoustic signals. Photoacoustic imaging (PAI) is a powerful preclinical diagnostic tool which provides real time images at a resolution of 40 μm. The leap toward clinical imaging has so far been hindered by the limited tissues penetration of near-infrared (NIR) pulsed laser radiation. Many academic and industrial research laboratories have met this challenge by designing devices, each with pros and cons, to enhance the photoacoustic (PA) signal. The major advantages of the hybrid graphene/PVA MBs construct, however, are (i) the preservation of graphene properties, (ii) biocompatibility, a consequence of the robust anchoring of pristine graphene to the bioinert surface of the PVA bubble, and (iii) a very good enhancement in a NIR spectral region of the PA signal, which does not overlap with the signals of PA active endogenous molecules such as hemoglobin.

Fluorographene based Ultrasensitive Ammonia Sensor

Single molecule detection using graphene can be brought by tuning the interactions via specific dopants. Electrostatic interaction between the most electronegative element fluorine (F) and hydrogen (H) is one of the strong interactions in hydrogen bonding, and here we report the selective binding of ammonia/ammonium with F in fluorographene (FG) resulting to a change in the impedance of the system. Very low limit of detection value of ~0.44 pM with linearity over wide range of concentrations (1 pM-0.1 μM) is achieved using the FG based impedance sensor, andthisscreen printed FG sensor works in both ionized (ammonium) and un-ionized ammonia sensing platforms. The interaction energies of FG and NH3/NH4(+) are evaluated using density functional theory calculations and the interactions are mapped. Here FGs with two different amounts of fluorinecontents -~5 atomic% (C39H16F2) and ~24 atomic% (C39H16F12) - are theoretically and experimentally studied for selective, high sensitive and ultra-low level detection of ammonia. Fast responding, high sensitive, large area patternable FG based sensor platform demonstrated here can open new avenues for the development of point-of-care devices and clinical sensors.

A Multi-Functional Tumor Theranostic Nanoplatform for MRI Guided Photothermal-Chemotherapy

PURPOSE

To develop a multi-functional theranostic nanoplatform with increased tumor retention, improving antitumor efficacy and decreased side effects of chemotherapy drugs.

METHODS

GO@Gd nanocomposites was synthesized via decorating gadolinium (Gd) nanoparticles (GdNP) onto graphene oxide (GO), and then functionalized by polyethylene glycol (PEG2000), folic acid (FA), a widely used tumor targeting molecule, was linked to GO@Gd-PEG, finally, doxorubicin (DOX) was loaded onto GO@Gd-PEG-FA and obtained a tumor-targeting drug delivery system (GO@Gd-PEG-FA/DOX). GO@Gd-PEG-FA/DOX was characterized and explored its theranostic applications both in a cultured MCF-7 cells and tumor-bearing mice.

RESULTS

GO@Gd-PEG-FA/DOX could efficiently cross the cell membranes, lead to more apoptosis and afford higher antitumor efficacy without obvious toxic effects to normal organs owing to its prolonged blood circulation and 7.6-fold higher DOX uptake of tumor than DOX. Besides, GO@Gd-PEG-FA/DOX also served as a powerful photothermal therapy (PTT) agent for thermal ablation of tumor and a strong T1-weighted contrast agent for tumor MRI diagnosis. The multi-functional nanoplatform also could selectively kill cancer cells in highly localized regions via the excellent tumor-targeting and MRI guided PTT abilities.

CONCLUSIONS

GO@Gd-PEG-FA/DOX exhibited excellent photothermal-chemotherapeutic efficacy, tumor-targeting property and tumor diagnostic ability.

Ultrahigh (19)F Loaded Cu1.75S Nanoprobes for Simultaneous (19)F Magnetic Resonance Imaging and Photothermal Therapy

(19)F magnetic resonance imaging (MRI) is a powerful noninvasive, sensitive, and accurate molecular imaging technique for early diagnosis of diseases. The major challenge of (19)F MRI is signal attenuation caused by the reduced solubility of probes with increased number of fluorine atoms and the restriction of molecular mobility. Herein, we present a versatile one-pot strategy for the fabrication of a multifunctional nanoprobe with high (19)F loading (∼2.0 × 10(8 19)F atoms per Cu1.75S nanoparticle). Due to the high (19)F loading and good molecular mobility that results from the small particle size (20.8 ± 2.0 nm) and ultrathin polymer coating, this nanoprobe demonstrates ultrahigh (19)F MRI signal. In vivo tests show that this multifunctional nanoprobe is suitable for (19)F MRI and photothermal therapy. This versatile fabrication strategy has also been readily extended to other single-particle nanoprobes for ablation and sensitive multimodal imaging.

Ultrahigh (19)F Loaded Cu1.75S Nanoprobes for Simultaneous (19)F Magnetic Resonance Imaging and Photothermal Therapy

(19)F magnetic resonance imaging (MRI) is a powerful noninvasive, sensitive, and accurate molecular imaging technique for early diagnosis of diseases. The major challenge of (19)F MRI is signal attenuation caused by the reduced solubility of probes with increased number of fluorine atoms and the restriction of molecular mobility. Herein, we present a versatile one-pot strategy for the fabrication of a multifunctional nanoprobe with high (19)F loading (∼2.0 × 10(8 19)F atoms per Cu1.75S nanoparticle). Due to the high (19)F loading and good molecular mobility that results from the small particle size (20.8 ± 2.0 nm) and ultrathin polymer coating, this nanoprobe demonstrates ultrahigh (19)F MRI signal. In vivo tests show that this multifunctional nanoprobe is suitable for (19)F MRI and photothermal therapy. This versatile fabrication strategy has also been readily extended to other single-particle nanoprobes for ablation and sensitive multimodal imaging.

Magnetic and fluorescent carbon-based nanohybrids for multi-modal imaging and magnetic field/NIR light responsive drug carriers

This mini-review summarizes the latest developments and addresses the future perspectives of carbon-based magnetic and fluorescent nanohybrids in the biomedical field.

Synthesis of a fluorinated graphene oxide–silica nanohybrid: improving oxygen affinity

An easy method to selectively introduce specific fluorotails into a graphene oxide–silica nanohybrid. Fluoro-functionalization increases the oxygen exchange at saturation.

Oxidative Stress and Mitochondrial Activation as the Main Mechanisms Underlying Graphene Toxicity against Human Cancer Cells

Due to the development of nanotechnology graphene and graphene-based nanomaterials have attracted the most attention owing to their unique physical, chemical, and mechanical properties. Graphene can be applied in many fields among which biomedical applications especially diagnostics, cancer therapy, and drug delivery have been arousing a lot of interest. Therefore it is essential to understand better the graphene-cell interactions, especially toxicity and underlying mechanisms for proper use and development. This review presents the recent knowledge concerning graphene cytotoxicity and influence on different cancer cell lines.

Carbon fluoroxide nanoparticles as fluorescent labels and sonosensitizers for theranostic applications

Carbon fluoroxide (CFO) nanoparticles (NPs) produced from silicon carbide wafers are used as both fluorescent probes and sonosensitizers for theranostic application. In vitro cell tests were carried out to investigate the feasibility of ultrasound-based therapy with the use of the CFO NPs. The NPs that penetrated inside the cells were shown to provoke cell destruction after application of an ultrasound treatment. No significant toxic effect was observed when the cells were treated with NP concentrations up to 0.5 mg ml^-1 without applying ultrasound treatment. The obtained results open a new way toward cancer therapy strategies.

Theranostic applications of carbon nanomaterials in cancer: Focus on imaging and cargo delivery

Carbon based nanomaterials have attracted significant attention over the past decades due to their unique physical properties, versatile functionalization chemistry, and biological compatibility. In this review, we will summarize the current state-of-the-art applications of carbon nanomaterials in cancer imaging and drug delivery/therapy. The carbon nanomaterials will be categorized into fullerenes, nanotubes, nanohorns, nanodiamonds, nanodots and graphene derivatives based on their morphologies. The chemical conjugation/functionalization strategies of each category will be introduced before focusing on their applications in cancer imaging (fluorescence/bioluminescence, magnetic resonance (MR), positron emission tomography (PET), single-photon emission computed tomography (SPECT), photoacoustic, Raman imaging, etc.) and cargo (chemo/gene/therapy) delivery. The advantages and limitations of each category and the potential clinical utilization of these carbon nanomaterials will be discussed. Multifunctional carbon nanoplatforms have the potential to serve as optimal candidates for image-guided delivery vectors for cancer.

Graphene-based nanomaterials as molecular imaging agents

Molecular imaging (MI) is a noninvasive, real-time visualization of biochemical events at the cellular and molecular level within tissues, living cells, and/or intact objects that can be advantageously applied in the areas of diagnostics, therapeutics, drug discovery, and development in understanding the nanoscale reactions including enzymatic conversions and protein-protein interactions. Consequently, over the years, great advancement has been made in the development of a variety of MI agents such as peptides, aptamers, antibodies, and various nanomaterials (NMs) including single-walled carbon nanotubes. Recently, graphene, a material popularized by Geim & Novoselov, has ignited considerable research efforts to rationally design and execute a wide range of graphene-based NMs making them an attractive platform for developing highly sensitive MI agents. Owing to their exceptional physicochemical and biological properties combined with desirable surface engineering, graphene-based NMs offer stable and tunable visible emission, small hydrodynamic size, low toxicity, and high biocompatibility and thus have been explored for in vitro and in vivo imaging applications as a promising alternative of traditional imaging agents. This review begins by describing the intrinsic properties of graphene and the key MI modalities. After which, we provide an overview on the recent advances in the design and development as well as physicochemical properties of the different classes of graphene-based NMs (graphene-dye conjugates, graphene-antibody conjugates, graphene-nanoparticle composites, and graphene quantum dots) being used as MI agents for potential applications including theranostics. Finally, the major challenges and future directions in the field will be discussed.

Tolerance and long-term MRI imaging of gadolinium-modified meshes used in soft organ repair

Background

Synthetic meshes are frequently used to reinforce soft tissues. The aim of this translational study is to evaluate tolerance and long-term MRI visibility of two recently developed Gadolinium-modified meshes in a rat animal model.

Materials and Methods

Gadolinium-poly-ε-caprolactone (Gd-PCL) and Gadolinium-polymethylacrylate (Gd-PMA) modified meshes were implanted in Wistar rats and their tolerance was assessed daily. Inflammation and biocompatibility of the implants were assessed by histology and immunohistochemistry after 30 days post implantation. Implants were visualised by 7T and 3T MRI at day 30 and at day 90. Diffusion of Gadolinium in the tissues of the implanted animals was assessed by Inductively Coupled Plasma Mass Spectrometry.

Results

Overall Gd-PMA coated implants were better tolerated as compared to those coated with Gd-PCL. In fact, Gd-PMA implants were characterised by a high ratio collagen I/III and good vascularisation of the integration tissues. High resolution images of the coated mesh were obtained in vivo with experimental 7T as well as 3T clinical MRI. Mass spectrometry analyses showed that levels of Gadolinium in animals implanted with coated mesh were similar to those of the control group.

Conclusions

Meshes coated with Gd-PMA are better tolerated as compared to those coated with Gd-PCL as no signs of erosion or significant inflammation were detected at 30 days post implantation. Also, Gd-PMA coated meshes were clearly visualised with both 7T and 3T MRI devices. This new technique of mesh optimisation may represent a valuable tool in soft tissue repair and management.

Cytotoxicity of fluorographene

Fluorinated graphenes (F-G) might inevitably be released into the environment through disposal and wearing of future commercial products incorporated with F-G. Therefore, we determined their cytotoxicity in this study.

An ‘all in one’ approach for simultaneous chemotherapeutic, photothermal and magnetic hyperthermia mediated by hybrid magnetic nanoparticles

Trimodal (chemo-photothermal and MHT) lethality imparted by triple targeted dual drug loaded hybrid MNPs.

Acid induced fluorinated graphene oxide

Brown graphene oxide was interestingly tuned into nearly white fluorinated graphene oxide with rich oxygen groups under hydrothermal treatment with nitric and hydrofluoric acid.

Heteroatom substituted and decorated graphene: preparation and applications

The electronic structure and surface chemistry of graphene can be tuned subtly by doping with heteroatoms, which induces unique applications.

Fluorination on polyethylenimine allows efficient 2D and 3D cell culture gene delivery

Polyethylenimine (PEI) is one of the most promising polymeric gene vectors, however its applications are limited by serious cytotoxicity and moderate transfection efficacy. Fluorination is an efficient strategy to improve the transfection efficacy of cationic polymers while reducing their cytotoxicity. Here we grafted different fluoroalkyl chains to PEI via oxirane and anhydride reactions. The fluorinated PEIs show superior transfection efficacy on both 2D and 3D cell cultures to unmodified PEI. These fluorinated polymers allow efficient gene transfection at relatively low nitrogen to phosphorus ratios and thereby ensure low cytotoxicity on the transfected cells. Fluorinated PEIs prepared via the oxirane reaction are much more stable in aqueous solutions than the ones prepared by the anhydride reaction and show reproducible gene transfection during a period of 6 months. This study extends the applicable scope of fluorination on improving the transfection efficacy of polymers and generates a list of gene vectors for efficient 2D and 3D cell culture gene transfection.

Surface engineering of graphene-based nanomaterials for biomedical applications

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

Improved heterogeneous electron transfer kinetics of fluorinated graphene derivatives

Though graphitic carbons are commercially available for various electrochemical processes, their performance is limited in terms of various electrochemical activities. Recent experiments on layered carbon materials, such as graphene, demonstrated an augmented performance of these systems in all electrochemical activities due to their unique electronic properties, enhanced surface area, structure and chemical stabilities. Moreover, flexibility in controlling electronic, as well as electrochemical activities by heteroatom doping brings further leverage in their practical use. Here, we study the electron transfer kinetics of fluorinated graphene derivatives, known as fluorinated graphene oxide (FGO) and its reduced form, RFGO. Enhanced electron transfer kinetics (heterogeneous electron transfer (HET)) is observed from these fluorinated systems in comparison to their undoped systems such as graphene oxide (GO) and reduced GO. A detailed study has been conducted using standard redox probes and biomolecules revealing the enhanced electro-catalytic activities of FGO and RFGO, and electron transfer rates are simulated theoretically. This study reveals that fluorine not only induces defects in graphitic lattice leading to an enhanced HET process but also can modify the electronic structure of graphene surface.

Ultrasound-guided photoacoustic imaging: current state and future development

Photoacoustic imaging, frequently coregistered with ultrasonic imaging, can provide functional and cellular/molecular information about tissue within the anatomical landmarks of an imaged region. This review details the fundamentals of photoacoustic imaging and its most promising imaging applications. Particular attention is paid to photoacoustic imaging's relationship with ultrasound, focusing on distinct differences and similarities between the two modalities and highlighting the mutual benefit of using both concurrently in certain preclinical and clinical applications. Much like its origins as an imaging modality were intertwined with ultrasonic imaging (namely, its acoustic transducers and hardware), the future of photoacoustic imaging-particularly in the clinical arena-similarly depends on ultrasound and its time-tested ability to provide real-time visualization of soft tissue.

Near-infrared light-responsive nanomaterials in cancer therapeutics

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