Plasmonic laser-responsive BioDissolve 3D-printed graphene@cisplatin-implant for prevention of post-surgical relapse of oral cancer.

The development of chemoresistance is a major obstacle in post-surgical adjuvant therapy of cancer, leading to cancer cell survival, recurrence, and metastasis. This study reports a 3D-printed plasmonic implant developed for the post-surgical adjuvant therapy of cisplatin-resistant cancer cells to prevent relapse. The implant was printed using optimized biomaterial ink containing biodegradable polymers [poly(L-lactide) and hydroxypropyl methylcellulose] blended suitably with laser-responsive graphene and chemo drug (Cisplatin). The irradiation of scar-driven 3D-printed implant with a laser stimulates graphene to generate a series of hyperthermia events leading to photothermolysis of cisplatin-resistant cancer cells under the combined influence of sustained cisplatin release. The developed personalized implant offers pH-responsive sustained drug release for 28 days. The implant exhibited acceptable biophysical properties (Tensile strength: 3.99 ± 0.15 MPa; modulus: 81 ± 9.58 MPa; thickness: 110 µm). The 3D-printed implant effectively reverses the chemoresistance in cisplatin-resistant 3D spheroid tumor models. Cytotoxicity assay performed using cisplatin-resistant (CisR) cell line revealed that the cell viability was reduced to 39.80 ± 0.68 % from 61.37 ± 0.98 % in CisR tumor spheroids on combined chemo-photothermal therapy. The combination therapy reduced the IC50 value from 71.05 µM to 48.73 µM in CisR spheroids. Apoptosis assay revealed an increase in the population of apoptotic cells (35.45 ± 1.56 % →52.53 ± 2.30 %) on combination therapy. A similar trend was observed in gene expression analysis, where the expression of pro-apoptotic genes Caspase 3 (3.73 ± 0.04 fold) and Bcl-2-associated X protein (BAX) (3.35 ± 0.02 fold) was increased on combination therapy. This 3D-printed, biodegradable implant with chemo-combined thermal ablating potential may provide a promising approach for the adjuvant treatment of resistant cancer.

Graphene Oxide Loaded with Protocatechuic Acid and Chlorogenic Acid Dual Drug Nanodelivery System for Human Hepatocellular Carcinoma Therapeutic Application.

Hepatocellular carcinoma or hepatoma is a primary malignant neoplasm that responsible for 75-90% of all liver cancer in humans. Nanotechnology introduced the dual drug nanodelivery method as one of the initiatives in nanomedicine for cancer therapy. Graphene oxide (GO) loaded with protocatechuic acid (PCA) and chlorogenic acid (CA) have shown some anticancer activities in both passive and active targeting. The physicochemical characterizations for nanocomposites were conducted. Cell cytotoxicity assay and lactate dehydrogenase were conducted to estimate cell cytotoxicity and the severity of cell damage. Next, nanocomposite intracellular drug uptake was analyzed using a transmission electron microscope. The accumulation and localization of fluorescent-labelled nanocomposite in the human hepatocellular carcinoma (HepG2) cells were analyzed using a fluorescent microscope. Subsequently, Annexin V- fluorescein isothiocyanate (FITC)/propidium iodide analysis showed that nanocomposites induced late apoptosis in HepG2 cells. Cell cycle arrest was ascertained at the G2/M phase. There was the depolarization of mitochondrial membrane potential and an upregulation of reactive oxygen species when HepG2 cells were induced by nanocomposites. In conclusion, HepG2 cells treated with a graphene oxide-polyethylene glycol (GOP)-PCA/CA-FA dual drug nanocomposite exhibited significant anticancer activities with less toxicity compared to pristine protocatechuic acid, chlorogenic acid and GOP-PCA/CA nanocomposite, may be due to the utilization of a folic acid-targeting nanodrug delivery system.

Graphene oxide loaded with tumor-targeted peptide and anti-cancer drugs for cancer target therapy.

In the present work, we constructed nanoscale graphene oxide (NGO) as a drug nanocarrier to improve the process of tumor-targeted drug releases, promote cellular uptake and accumulation of chemotherapy drugs in tumor tissues, and reduce the toxic effects of chemotherapy drugs on normal cells. Hence, great stability was obtained in the biological solution. Moreover, we designed an effective nanoparticle system for the doxorubicin (DOX) delivery targeting the oral squamous cell carcinoma (OSCC) by mediating the HN-1 (TSPLNIHNGQKL) through hydrogen and π-π bonds. DOX@NGO-PEG-HN-1 showed significantly higher cellular uptakes and cytotoxicity in OSCC cells (CAL-27 and SCC-25), compared to free DOX. Moreover, HN-1 showed considerable tumor-targeting and competition inhibition phenomenon. As we expected, the nanocarrier showed pH-responsive drug release. In total, our study represented a good technique to construct OSCC-targeted delivery of nanoparticles and improve the anticancer medicines' efficiency.

Influence of the Aspect Ratio of Iron Oxide Nanorods on Hysteresis-Loss-Mediated Magnetic Hyperthermia.

Owing to the problems associated with conventional cancer treatment methods, magnetic hyperthermia-based cancer therapy has gained importance recently. Achieving the desired heating effect at the site of the tumor with a minimal concentration of iron oxide nanoparticles (IONPs) and a safer field is necessary to explore the advantages of hyperthermia. For one to address this challenge, biocompatible IONPs with a desirable magnetic response at a tolerable field are necessary. In this work, magnetic shape anisotropy of iron oxide nanorods (NR) of different lengths (70, 115, 170, and 210 nm) with different aspect ratios ranging from 1.55 to 3.2 was explored to achieve higher hysteresis loss, in turn leading to better hyperthermia efficiency. The magnetic properties of the NRs with respect to the applied field were studied using micromagnetic simulation. Even though the nanorods with high aspect ratio showed a higher hysteresis loss of 69485 J/m3 at 2000 Oe, the field required to attain it was high and well beyond the safety limit. From nanorods of various aspect ratios, the nanorod with a lower aspect ratio of 1.55 and a length of 70 nm exhibited a better hysteresis loss and specific absorption rate (SAR) value of 4214 W g-1 was achieved at a frequency and alternating magnetic field of 400 kHz and 800 Oe, respectively. The PEGylated GO-Nanorod of 70 nm exhibited excellent antitumor efficacy in 4T1 tumor model mice by obstructing the tumor progression within a safer dosage and field.

Occupational exposure to graphene and silica nanoparticles. Part II: pilot study to identify a panel of sensitive biomarkers of genotoxic, oxidative and inflammatory effects on suitable biological matrices.

The available biomonitoring studies on workers producing/handling nanomaterials (NMs) focused on potential effects on respiratory, immune and cardio-vascular system. Aim of this study was to identify a panel of sensitive biomarkers and suitable biological matrices to evaluate particularly genotoxic and oxidative effects induced on workers unintentionally exposed to graphene or silica nanoparticles during the production process. These nanomaterials have been chosen for 'NanoKey' project, integrating the workplace exposure assessment (reported in part I) with the biomonitoring of exposed workers reported in the present work. Simultaneously to workplace exposure characterization, we monitored the workers using: Buccal Micronucleus Cytome (BMCyt) assay, fpg-comet test (lymphocytes), oxidized DNA bases 8-oxoGua, 8-oxoGuo and 8-oxodGuo measurements (urine), analysis of oxidative stress biomarkers in exhaled breath condensate (EBC), FENO measurement and cytokines release detection (serum). Since buccal cells are among the main targets of NM occupational exposure, particular attention was posed to the BMCyt assay that represents a noninvasive assay. This pilot study, performed on 12 workers vs.11 controls, demonstrates that BMCyt and fpg-comet assays are the most sensitive biomarkers of early, still reparable, genotoxic and oxidative effects. The findings suggest that these biomarkers could represent useful tools for the biomonitoring of workers exposed to nanoparticles, but they need to be confirmed on a high number of subjects. However, such biomarkers don't discriminate the effects of NM from those due to other chemicals used in the NM production process. Therefore, they could be suitable for the biomonitoring of workers exposed to complex scenario, including nanoparticles exposure.

Graphene oxide improves postoperative cognitive dysfunction by maximally alleviating amyloid beta burden in mice.

Rationale: Graphene oxide (GO) based nanomaterials have shown potential for the diagnosis and treatment of amyloid-ß (Aß)-related diseases, mainly on Alzheimer's disease (AD). However, these nanomaterials have limitations. How GO is beneficial to eliminate Aß burden, and its physiological function in Aß-related diseases, still needs to be investigated. Moreover, postoperative cognitive dysfunction (POCD) is an Aß-related common central nervous system complication, however, nanomedicine treatment is lacking. Methods: To evaluate the effects of GO on Aß levels, HEK293T-APP-GFP and SHSY5Y-APP-GFP cells are established. Intramedullary fixation surgery for tibial fractures under inhalation anesthesia is used to induce dysfunction of fear memory in mice. The fear memory of mice is assessed by fear conditioning test. Results: GO treatment maximally alleviated Aß levels by simultaneously reducing Aß generation and enhancing its degradation through inhibiting ß-cleavage of amyloid precursor protein (APP) and improving endosomal Aß delivery to lysosomes, respectively. In postoperative mice, the hippocampal Aß levels were significantly increased and hippocampal-dependent fear memory was impaired. However, GO administration significantly reduced hippocampal Aß levels and improved the cognitive function of the postoperative mice. Conclusion: GO improves fear memory of postoperative mice by maximally alleviating Aß accumulation, providing new evidence for the application of GO-based nanomedicines in Aß-related diseases.

Implant-based direction of magnetic nanoporous silica nanoparticles - influence of macrophage depletion and infection.

Implant associated infections are still key problem in surgery. In the present study, the combination of a magnetic implant with administered magnetic nanoporous silica nanoparticles as potential drug carriers was examined in mice in dependence of local infection and macrophages as influencing factors. Four groups of mice (with and without implant infection and with and without macrophage depletion) received a magnet on the left and a titanium control on the right hind leg. Then, fluorescent nanoparticles were administered and particle accumulations at implant surfaces and in inner organs as well as local tissue reactions were analyzed. Magnetic nanoparticles could be found at the surfaces of magnetic implants in different amounts depending on the treatment groups and only rarely at titanium surfaces. Different interactions of magnetic implants, particles, infection and surrounding tissues occurred. The general principle of targeted accumulation of magnetic nanoparticles could be proven.

Molecular targeting of bioconjugated graphene oxide nanocarriers revealed at a cellular level using label-free Raman imaging.

Two-dimensional materials as graphene oxide (GO) are able to accommodate labels as well as toxins for diagnostics and therapy, respectively. The transmembrane protein carbonic anhydrase (CA IX) is one of the molecules selectively expressed by tumor cells. Here, we demonstrate bioconjugation of GO to biotinylated M75 antibody highly selective towards CA IX. Based on a model system, binding between the bioconjugated GO-M75 and Madin-Darby Canine Kidney (MDCK) cells was evaluated. As proven by fluorescence-activated cell sorting, higher intake was observed for GO-M75 towards MDCK cells ectopically expressing CA IX protein on their surface when compared to control MDCK. In particular, we were able to localize GO nanocarrier crossing the membrane during endocytosis, thanks to the optical cross-sectioning of living cells in real-time employed the label-free confocal Raman microscopy. The increased affinity of the prepared GO-M75 molecular complexes validates the use of two-dimensional materials for future strategies of targeted cancer treatment.

Enhanced antitumor activity of bovine lactoferrin through immobilization onto functionalized nano graphene oxide: an in vitro/in vivo study.

This study aims to improve the anticancer activity of bovine lactoferrin through enhancing its stability by immobilization onto graphene oxide. Bovine lactoferrin was conjugated onto graphene oxide and the conjugation process was confirmed by FT-IR, SDS-PAGE, and UV spectrophotometry. Physical characterization was performed by DLS analysis and atomic force microscopy. The cytotoxicity and cellular uptake of the final construct (CGO-PEG-bLF) was inspected on lung cancer TC-1 cells by MTT assay and flow cytometry/confocal microscopy. The anticancer mechanism of the CGO-PEG-bLF was studied by cell cycle analysis, apoptosis assay, and western blot technique. Finally, the anticancer activity of CGO-PEG-bLF was assessed in an animal model of lung cancer. Size and zeta potential of CGO-PEG-bLF was obtained in the optimum range. Compared with free bLF, more cytotoxic activity, cellular uptake and more survival time was obtained for CGO-PEG-bLF. CGO-PEG-bLF significantly inhibited tumor growth in the animal model. Cell cycle arrest and apoptosis were more induced by CGO-PEG-bLF. Moreover, exposure to CGO-PEG-bLF decreased the phospho-AKT and pro-Caspase 3 levels and increased the amount of cleaved caspase 3 in the treated cells. This study revealed the potential of CGO-PEG as a promising nanocarrier for enhancing the therapeutic efficacy of anticancer agents.

Reduced graphene oxide mitigates cadmium-induced cytotoxicity and oxidative stress in HepG2 cells.

Numerous applications of reduced graphene oxide (RGO) and pervasive cadmium (Cd) have led concern about their co-exposure to the environment and human. We studied the combined effects of RGO and Cd in human liver (HepG2) cells. Initially, we found that RGO (up to 50 µg/ml) did not harm to HepG2 cells while Cd induced dose-dependent (1-10 µg/ml) cytotoxicity. Exciting observations were that a non-cytotoxic concentration of RGO (25 µg/ml) effectively mitigates the toxic effects of Cd (2 µg/ml) such as cell viability reduction, lactate dehydrogenase release, and irregular cell morphology. Cd-induced cell cycle arrest, induction of caspases (3 and 9) enzymes activity, and loss of mitochondrial membrane potential were also significantly alleviated by RGO co-exposure. Moreover, generation of pro-oxidants (reactive oxygen species and hydrogen peroxide levels) and depletion of antioxidants (glutathione level and superoxide dismutase activity) due to Cd exposure was effectively attenuated by RGO co-exposure. Mitigating effect of RGO could be due to strong adsorption of Cd on the large surface area of RGO sheets, which decrease the cellular uptake and bioavailability of Cd for HepG2 cells. This study warrants future research on potential mechanisms of mitigating effects of RGO against Cd-induced toxicity in animal models.

Electrospun poly-caprolactone/graphene oxide/quercetin nanofibrous scaffold for wound dressing: Evaluation of biological and structural properties.

AIMS: In this study, for the first time, the effect of quercetin (Q) on the characteristic properties, antimicrobial activity, and cell viability of polycaprolactone (PCL)/graphene oxide (GO) electrospun scaffold was investigated. MAIN METHODS: Quercetin loaded graphene oxide nanoparticles have been incorporated into the poly-caprolactone solution, and their mixture has been electrospun to be applied as a nanofibrous scaffold for wound dressing and tissue engineering applications. The properties of scaffolds, like their morphology, tensile strength, hydrophilicity, and in vitro biological performance, are investigated. KEY FINDINGS: The SEM micrographs reveal the uniform bead-free nanofibers with smooth structures have been successfully fabricated via the electrospinning procedure. The overall average of cell viability of NIH/3 T3 fibroblast cells on scaffolds is 95% that means the scaffolds have no toxicity, and FESEM shows cells attach and proliferate on scaffolds. Moreover, among all the fabricated scaffolds, the maximum release of quercetin belongs to PCL/GO/Q 0.5 with about 70% after 15 days, and this scaffold reduces bacterial growth by about 50% after 12 h shows the excellent effect of GO/Q on the antibacterial activity of PCL nanofibers. SIGNIFICANCE: The results confirm that more than 1% of GO has some cytotoxicity, which limits its concentration; therefore, a second antibacterial agent is essential to improve the antibacterial activity of PCL/GO scaffold, and quercetin shows that it is an excellent candidate for this purpose.

Liposomal nanotheranostics for multimode targeted in vivo bioimaging and near-infrared light mediated cancer therapy.

Developing a nanotheranostic agent with better image resolution and high accumulation into solid tumor microenvironment is a challenging task. Herein, we established a light mediated phototriggered strategy for enhanced tumor accumulation of nanohybrids. A multifunctional liposome based nanotheranostics loaded with gold nanoparticles (AuNPs) and emissive graphene quantum dots (GQDs) were engineered named as NFGL. Further, doxorubicin hydrochloride was encapsulated in NFGL to exhibit phototriggered chemotherapy and functionalized with folic acid targeting ligands. Encapsulated agents showed imaging bimodality for in vivo tumor diagnosis due to their high contrast and emissive nature. Targeted NFGL nanohybrids demonstrated near infrared light (NIR, 750 nm) mediated tumor reduction because of generated heat and Reactive Oxygen Species (ROS). Moreover, NFGL nanohybrids exhibited remarkable ROS scavenging ability as compared to GQDs loaded liposomes validated by antitumor study. Hence, this approach and engineered system could open new direction for targeted imaging and cancer therapy.

Optically controlled hybrid metamaterial of plasmonic spiky gold inbuilt graphene sheets for bimodal imaging guided multimodal therapy.

The development of multifunctional molecular diagnostic platforms for the concordant visualization and treatment of diseases with high sensitivity and resolution has recently become a crucial strategy in cancer management. Thus, engineering functional metamaterials with high therapeutic and imaging capabilities to elucidate diseases from their morphological behaviors to physiological mechanisms is an unmet need in the current scenario. Here, we report the design of a unique hybrid plasmonic nanoarchitecture for targeted multiple phototherapies of breast cancer by simultaneous real-time monitoring through fluorescence and surface-enhanced Raman scattering (SERS) techniques. The nanoframework consisted of plasmonic gold-graphene hybrids tethered with folic acid-ligated chitosan-modified photosensitizer (PpIX) to afford target-specific localized photothermal and photodynamic therapy. The hybrid vehicle also served as an excellent nanocarrier for the efficient loading and stimuli-responsive release of the chemotherapeutic drug doxorubicin (DOX) to enhance the therapeutic efficacy, thereby forming a trimodal nanomedicine against cancer. The cytotoxic effects induced by the cumulative action of the triplet therapeutic tools were visualized through both fluorescence and SERS imaging channels. Moreover, it also generated synchronized therapeutic effects resulting in the effective regression of tumor volume without propagating any toxic effects to other organs of the animals. Taken together, by virtue of strong light-matter interactions, the nanoprobe showed enhanced photoadsorption, which facilitated amplified light-reactive therapeutic and imaging efficacies along with targeted and enhanced chemotherapy, both in vitro and in vivo, which may offer promising outcomes in clinical research.

Al centre-powered graphitic nanozyme with high catalytic efficiency for pH-independent chemodynamic therapy of cancer.

An Al centre-powered graphitic nanozyme derived from a metal organic framework was first developed for a chemodynamic tumor treatment. By virtue of the rapid and efficient generation of ˙OH in the slightly acidic tumor microenvironment, this nanozyme afforded high anti-tumor efficacy both in living cells and in vivo.

Enhancement radiation-induced apoptosis in C6 glioma tumor-bearing rats via pH-responsive magnetic graphene oxide nanocarrier.

5-iodo-2-deoxyuridine (IUdR) has been demonstrated to induce an appreciable radiosensitizing effect on glioblastoma patients, but due to the short circulation half-life times and failure to pass through the blood-brain barrier (BBB), its clinical use is limited. Accordingly, in this study, we used magnetic graphene oxide (NGO/SPIONs) nanoparticles coated with PLGA polymer as a dynamic nanocarrier for IUdR and, evaluated its sensitizing enhancement ratio in combination with a single dose X-ray at clinically megavoltage energies for treatment of C6 glioma rats. Nanoparticles were characterized using Zetasizer and TEM microscopy, and in vitro biocompatibility of nanoparticles was assessed with MTT assay. IUdR/MNPs were intravenously administered under a magnetic field (1.3 T) on day 13 after the implantation of C6 cells. After a day following the injection, rats exposed with radiation (8 Gy). ICP-OES analysis data indicated an effective magnetic targeting, leading to remarkably improved penetration through the BBB. In vivo release analysis with HPLC indicated sustained release of IUdR and, prolonged the lifespan in plasma (P < .01). In addition, our findings revealed a synergistic effect for IUdR/MNPs coupled with radiation, which significantly inhibited the tumor expansion (>100%), prolonged the survival time (>100%) and suppressed the anti-apoptotic response of glioma rats by increasing Bax/Bcl-2 ratio (2.13-fold) in compared with the radiation-only. In conclusion, besides high accumulation in targeted tumor sites, the newly developed IUdR/MNPs, also exhibited the ability of IUdR/MNPs to significantly enhance radiosensitizing effect, improve therapeutic efficacy and increase toxicity for glioma-bearing rats.

Impact of graphene oxide functionalized with doxorubicin on viability of mouse hepatoma MH-22A cells.

The evaluation of the cyto- and bio-compatibility is a critical step in the development of graphene oxide (GO) as a new promising material for in vivo biomedical applications. In this study, we report the impact of GO, with and without the addition of bovine serum albumin and anticancer drug- doxorubicin (DOX) on cancer (mouse hepatoma MH-22A) cells viability and the estimation of the intracellular distribution of GO inside the cells in vitro. The viability tests were performed using a colony formation assay. The intracellular distribution of GO was estimated using Raman spectroscopy and imaging. It was found that the functionalized GO with doxorubicin strengthens Doxorubicin, as anticancer drug effect. Therefore, it was revealed that a statistically significant result - the viability of MH-22A cells was approx. 20% lower than using DOX separately (from 57% to 79%, respectively). The results of viability tests correlate with results of atomic force microscopy and Raman spectroscopy and imaging findings.

Development of amine-functionalized superparamagnetic iron oxide nanoparticles anchored graphene nanosheets as a possible theranostic agent in cancer metastasis.

The major objective of the present investigation was to assess the targeting potential of a designed system for breast cancer at metastatic phases with imaging ability. In a nutshell, we have developed surface-engineered graphene oxide (GO) nanosheets by covalent linking with amine-functionalized iron oxide nanoparticles (IONPs) (GOIOIs). Gefitinib (Gf) was selected as a model drug and entrapped in between exfoliated GO sheets (GOIGF) via π-π* stacking before functionalization with IONPs. Preliminary characterization of GO, IONPs, GOIOI, and GOIGF was performed using UV-visible and Fourier transform infrared spectroscopy. Scanning and transmission electron microscopy studies confirmed successful surface engineering of GO with IONPs. The in vitro drug release study demonstrated sustained release of Gf. The magnetic behavior of IONPs and GOIOI demonstrated a sigmoidal-shaped hysteresis loop with superparamagnetic properties. The in vitro cell cytotoxicity assay was carried out on MDA-MB-231 breast cancer adenocarcinoma cell lines. The cell cytotoxicity assay showed 61.18% inhibition of cell growth with 30 ppm concentration containing 64% of the drug, whereas 100% of the pure drug revealed only 56% of inhibition. In the near future, GOIOI could be tailored further for theranostic research, especially for metastatic cancers. Graphical abstract.

Graphene Oxide-Grafted Magnetic Nanorings Mediated Magnetothermodynamic Therapy Favoring Reactive Oxygen Species-Related Immune Response for Enhanced Antitumor Efficacy.

In this study, a magnetothermodynamic (MTD) therapy is introduced as an efficient systemic cancer treatment, by combining the magnetothermal effect and the reactive oxygen species (ROS)-related immunologic effect, in order to overcome the obstacle of limited therapeutic efficacy in current magnetothermal therapy (MTT). This approach was achieved by the development of an elaborate ferrimagnetic vortex-domain iron oxide nanoring and graphene oxide (FVIOs-GO) hybrid nanoparticle as the efficient MTD agent. Such a FVIOs-GO nanoplatform was shown to have high thermal conversion efficiency, and it was further proved to generate a significantly amplified ROS level under an alternating magnetic field (AMF). Both in vitro and in vivo results revealed that amplified ROS generation was the dominant factor in provoking a strong immune response at a physiological tolerable temperature below 40 °C in a hypoxic tumor microenvironment. This was supported by the exposure of calreticulin (CRT) on 83% of the 4T1 breast cancer cell surface, direct promotion of macrophage polarization to pro-inflammatory M1 phenotypes, and further elevation of tumor-infiltrating T lymphocytes. As a result of the dual action of magnetothermal effect and ROS-related immunologic effect, impressive in vivo systemic therapeutic efficacy was attained at a low dosage of 3 mg Fe/kg with two AMF treatments, as compared to that of MTT (high dosage of 6-18 mg/kg under four to eight AMF treatments). The MTD therapy reported here has highlighted the inadequacy of conventional MTT that solely relies on the heating effect of the MNPs. Thus, by employing a ROS-mediated immunologic effect, future cancer magnetotherapies can be designed with greatly improved antitumor capabilities.

Well-defined Graphene Oxide as a Potential Component in Lung Cancer Therapy.

BACKGROUND: Graphene oxide (GO) has unique physical and chemical properties that can be used in anticancer therapy - especially as a drug carrier. Graphene oxide, due to the presence of several hybrid layers of carbon atoms (sp2), has a large surface for highly efficient drug loading. In addition, GO with a large number of carboxyl, hydroxyl and epoxy groups on its surface, can charge various drug molecules through covalent bonds, hydrophobic interactions, hydrogen bonds and electrostatic interactions. OBJECTIVE: The aim of our work was to evaluate the possibility of future use of graphene oxide as an anticancer drug carrier. METHODS: In this paper, we present GO synthesis and characterization, as well as a study of its biological properties. The cytotoxic effect of well-defined graphene oxide was tested on both carcinoma and non-malignant cells isolated from the same organ, which is not often presented in the literature. RESULTS: The performed research confirmed that GO in high concentrations (> 300 µgmL-1) selectively decreased the viability of cancer cell line. Additionally, we showed that the GO flakes have a high affinity to cancer cell nucleus which influences their metabolism (inhibition of cancer cell proliferation). Moreover, we have proved that GO in high concentrations can cause cell membrane damage and generate reactive oxygen species on a low level mainly in cancer cells. CONCLUSION: The proposed GO could be useful in anticancer therapy. A high concentration of GO selectively causes the death of tumor cells, whereas GO with low concentration could be a potential material for anticancer drug loading.

Glycyrrhetinic acid-modified graphene oxide mediated siRNA delivery for enhanced liver-cancer targeting therapy.

Graphene oxide (GO) has attracted huge attention in biomedical field in recent years. However, limited attempts have been invested in utilizing GO on active targeted delivery for gene therapy in liver cancer treatments. Glycyrrhetinic acid (GA) has been reported to be widely used as a targeting ligand to functionalize nanomaterials to treat hepatocellular carcinoma. In this article, GA is employed as a liver targeting ligand to construct GA, polyethylene glycol (PEG), polyamidoamine dendrimer (Dendrimer) and nano-graphene oxide (NGO) conjugate (GA-PEG-NGO-Dendrimer, GPND) for siRNA delivery for the first time. As we expected, GPND exhibited excellent stability, low toxicity, negligible hemolytic activity and remarkably high transfection efficiency in vitro. We also found effective VEGFa gene silencing in both mRNA and protein level in HepG2 cells. Notably, siRNA efficiently gathered in liver tumor tissues by the delivery of GPND, and eventually the growth of tumor tissues were inhibited with enhanced targeting capability and no obvious pathological changes. Moreover, histopathological results preliminarily support the high in vivo safety of GPND/anti-VEGFa siRNA nanocomplex. Collectively, GPND/siRNA nanocomplex, with high safety, targeting and transfection as well as prolonged half-life, is a promising nanomedicine and may provide a new direction for highly-specific targeted gene therapy.