Stat3 shRNA delivery with folate receptor-modified multi-functionalized graphene oxide particles for combined infrared radiation and gene therapy in hepatocellular carcinoma

As a vital oncogene, a variety of inhibitors targeting Stat3 and its various upstream signaling pathways has been explored. Since small molecules, peptidomimetics and other peptide inhibitors usually lead to side effects and difficult administration, gene therapeutics that have characteristics of low toxicity and high targeting, make them an attractive alternative for targeting Stat3. A major challenge to this approach is the lack of safe delivery systems for in-vivo applications. Among the various siRNA delivery systems, nanoparticles emerge as a new tool for gene delivery with high biocompatibility, low cost, and minimal toxicity. In this study, we developed a graphene oxide (GO)-based nanocarrier, GO-polyethyleneimine (PEI)-polyethylene glycol (PEG)-folic acid (FA), as a tool targeting for Stat3-specific shRNA to mouse hepatoma cells in vitro and in vivo . Infrared photothermal therapy was combined in vivo since GO has the characteristic of infrared absorbability. Our results suggest a significant tumor growth inhibition after treatment with GO-PEI-PEG-FA- sh-Stat3 combined with infrared photothermal therapy. Thus, GO-PEI-PEG-FA appears to be a novel nano-transformer that could be used in the clinics in future.

Au nanoparticles decorated nanographene oxide-based platform: Synthesis, functionalization and assessment of photothermal activity

A novel hybrid nanocomposite formed of carboxylated Nano Graphene Oxide (c-NGO), highly densely decorated by monodisperse citrate-coated Au nanoparticles (c-NGO/Au NPs), is synthesized and thoroughly characterized for photothermal applications. A systematic investigation of the role played by the synthetic parameters on the Au NPs decoration of the c-NGO platform is performed, comprehensively studying spectroscopic and morphological characteristics of the achieved nanostructures, thus elucidating their still not univocally explained synthesis mechanism. Remarkably, the Au NPs coating density of the c-NGO sheets is much higher than state-of-the-art systems with analogous composition prepared with different approaches, along with a higher NPs size dispersion. A novel theoretical approach for estimating the average number of NPs per sheet, combining DLS and TEM results, is developed. The assessment of the c-NGO/Au NPs photothermal activity is performed under continuous wave (CW) laser irradiation, at 532 nm and 800 nm, before and after functionalization with PEG-SH. c-NGO/Au NPs composite behaves as efficient photothermal agent, with a light into heat conversion ability higher than that of the single components. The c-NGO/Au NPs compatibility for photothermal therapy is assessed by in vitro cell viability tests, which show no significant effects of c-NGO/Au NPs, as neat and PEGylated, on cell metabolic activity under the investigated conditions. These results demonstrate the great potential held by the prepared hybrid nanocomposite for photothermal conversion technologies, indicating it as particularly promising platform for photothermal ablation of cancer cells.

Novel nanocarriers for silencing anti-phagocytosis CD47 marker in acute myeloid leukemia cells

Acute myeloid leukemia (AML), a malignant disorder of Hematopoietic stem cells, can escape immunosurveillance by over expression of the cluster of differentiation 47 (CD47) marker, which functions as an inhibitory signal, suppressing phagocytosis by binding to signal regulatory protein α (SIRPα) on macrophages. AML is treated mainly by chemotherapy, which has drastic side effects and poor outcomes for the patients. Most AML patients develop drug resistance, so other methods to treat AML are highly required. Small interfering RNA (siRNA) is considered as an antitumor therapeutic due to its ability to silence genes associated with the overexpressed cancer markers and subsequently re-sensitize cancer cells. However, delivering siRNA into cells faces challenges, and the development of an effective delivery system is desired for successful silencing at the gene level. Herein, we report the usage of different formulations of graphene oxide (GO) as carriers for the delivery of CD47_siRNA (siRNA against CD47) into AML cells in vitro. The polyethylene glycol (PEG) and dendrimers (PAMAM) modified GO with small flake sizes achieved the highest silencing efficiency of the anti-phagocytosis marker CD47 gene, resulted CD47 protein down-regulation in AML cells. Moreover, the concentration at which the GO-based formulations was used has shown no cytotoxicity in AML cells or normal blood cells, which could be used to screen potential drugs for targeted gene therapy in AML.

Recent Advances in Designing Electroconductive Biomaterials for Cardiac Tissue Engineering

Implantable cardiac patches and injectable hydrogels are among the most promising therapies for cardiac tissue regeneration following myocardial infarction. Incorporating electrical conductivity into these patches and hydrogels is found to be an efficient method to improve cardiac tissue function. Conductive nanomaterials such as carbon nanotube, graphene oxide, gold nanorod, as well as conductive polymers such as polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate are appealing because they possess the electroconductive properties of semiconductors with ease of processing and have potential to restore electrical signaling propagation through the infarct area. Numerous studies have utilized these materials for regeneration of biological tissues that possess electrical activities, such as cardiac tissue. In this review, recent studies on the use of electroconductive materials for cardiac tissue engineering and their fabrication methods are summarized. Moreover, recent advances in developing electroconductive materials for delivering therapeutic agents as one of emerging approaches for treating heart diseases and regenerating damaged cardiac tissues are highlighted.

Graphene-laden hydrogels: A strategy for thermally triggered drug delivery

The synthesis of graphene-based materials has attracted considerable attention in drug delivery strategies. Indeed, the conductivity and mechanical stability of graphene have been investigated for controlled and tunable drug release via electric or mechanical stimuli. However, the design of a thermo-sensitive scaffold using pristine graphene (without distortions related to the oxidation processes) has not been deeply investigated yet, although it may represent a promising approach for several therapeutic treatments. Here, few-layer graphene was used as a nanofiller in a hydrogel system with a thermally tunable drug release profile. In particular, varying the temperature (25 °C, 37 °C and 44 °C), responsive drug releases were noticed and hypothesized depending on the formation and perturbation of π-π interactions involving graphene, the polymeric matrix and the model drug (diclofenac). As a result, these hybrid hydrogels show a potential application as thermally triggered drug release systems in several healthcare scenarios.

Mechanically tough and highly stretchable poly(acrylic acid) hydrogel cross-linked by 2D graphene oxide

Incorporation of a novel GO based cross-linker into the conventional poly(acrylic acid) hydrogel remarkably enhances the toughness and stretchability.

A Candidate for Multitopic Probes for Ligand Discovery in Dynamic Combinatorial Chemistry

Multifunctionalized materials are expected to be versatile probes to find specific interactions between a ligand and a target biomaterial. Thus, efficient methods to prepare possible combinations of the functionalities is desired. The concept of dynamic combinatorial chemistry (DCC) is ideal for the generation of any possible combination, as well as screening for target biomaterials. Here, we propose a new molecular design of multitopic probes for ligand discovery in DCC. We synthesized a new Gable Porphyrin, GP1, having prop-2-yne groups as a scaffold to introduce various functional groups. GP1 is a bis(imidazolylporphyrinatozinc) compound connected through a 1,3-phenylene moiety, and it gives macrocycles spontaneously and quantitatively by strong imidazole-to-zinc complementary coordination. Some different types of functional groups were introduced into GP1 in high yields. Formation of heterogeneous macrocycles composed of GP1 derivatives having different types of substituents was accomplished under equilibrium conditions. These results promise that enormous numbers of macrocycles having various functional groups can be provided when the kinds of GP components increase. These features are desirable for DCC, and the present system using GP1 is a potential candidate to provide a dynamic combinatorial library of multitopic probes to discover specific interactions between a ligand and a biomaterial.

Advances on graphene-based nanomaterials for biomedical applications

Graphene-based nanomaterials, such as graphene oxide and reduced graphene oxide, have been attracting increasing attention in the field of biology and biomedicine over the past few years. Incorporation of these novel materials with drug, gene, photosensitizer and other cargos to construct novel delivery systems has witnessed rapid advance on the basis of their large surface area, distinct surface properties, excellent biocompatibility and pH sensitivity. Moreover, the inherent photothermal effect of these appealing materials enables them with the ability of killing targeting cells via a physical mechanism. Recently, more attentions have been attached to tissue engineering, including bone, neural, cardiac, cartilage, musculoskeletal, and skin/adipose tissue engineering, due to the outstanding mechanical strength, stiffness, electrical conductivity, various two-dimensional (2D) and three-dimensional (3D) morphologies of graphene-based nanomaterials. Herein, emerging applications of these nanomaterials in bio-imaging, drug/gene delivery, phototherapy, multimodality therapy and tissue engineering were comprehensively reviewed. Inevitably, the burgeon of this kind of novel materials leads to the endeavor to consider their safety so that this issue has been deeply discussed and summarized in our review. We hope that this review offers an overall understanding of these nanomaterials for later in-depth investigations.

Dual Roles of Graphene Oxide To Attenuate Inflammation and Elicit Timely Polarization of Macrophage Phenotypes for Cardiac Repair

Development of localized inflammatory environments by M1 macrophages in the cardiac infarction region exacerbates heart failure after myocardial infarction (MI). Therefore, the regulation of inflammation by M1 macrophages and their timely polarization toward regenerative M2 macrophages suggest an immunotherapy. Particularly, controlling cellular generation of reactive oxygen species (ROS), which cause M1 differentiation, and developing M2 macrophage phenotypes in macrophages propose a therapeutic approach. Previously, stem or dendritic cells were used in MI for their anti-inflammatory and cardioprotective potentials and showed inflammation modulation and M2 macrophage progression for cardiac repair. However, cell-based therapeutics are limited due to invasive cell isolation, time-consuming cell expansion, labor-intensive and costly ex vivo cell manipulation, and low grafting efficiency. Here, we report that graphene oxide (GO) can serve as an antioxidant and attenuate inflammation and inflammatory polarization of macrophages via reduction in intracellular ROS. In addition, GO functions as a carrier for interleukin-4 plasmid DNA (IL-4 pDNA) that propagates M2 macrophages. We synthesized a macrophage-targeting/polarizing GO complex (MGC) and demonstrated that MGC decreased ROS in immune-stimulated macrophages. Furthermore, DNA-functionalized MGC (MGC/IL-4 pDNA) polarized M1 to M2 macrophages and enhanced the secretion of cardiac repair-favorable cytokines. Accordingly, injection of MGC/IL-4 pDNA into mouse MI models attenuated inflammation, elicited early polarization toward M2 macrophages, mitigated fibrosis, and improved heart function. Taken together, the present study highlights a biological application of GO in timely modulation of the immune environment in MI for cardiac repair. Current therapy using off-the-shelf material GO may overcome the shortcomings of cell therapies for MI.

Gene delivery ability of polyethylenimine and polyethylene glycol dual-functionalized nanographene oxide in 11 different cell lines

We recently developed a polyethylenimine (PEI) and polyethylene glycol (PEG) dual-functionalized reduced graphene oxide (GO) (PEG-nrGO-PEI, RGPP) for high-efficient gene delivery in HepG2 and Hela cell lines. To evaluate the feasibility and applicability of RGPP as a gene delivery carrier, we here assessed the transfection efficiency of RGPP on gene plasmids and siRNA in 11 different cell lines. Commercial polyalkyleneimine cation transfection reagent (TR) was used as comparison. In HepG2 cells, RGPP exhibited much stronger delivery ability for siRNA and large size plasmids than TR. For green fluorescent protein (GFP) plasmid, RGPP showed about 47.1% of transfection efficiency in primary rabbit articular chondrocytes, and about 27% of transfection efficiency in both SH-SY5Y and A549 cell lines. RGPP exhibited about 37.2% of GFP plasmid transfection efficiency in EMT6 cells and about 26.0% of GFP plasmid transfection efficiency in LO2 cells, but induced about 33% of cytotoxicity in both cell lines. In 4T1 and H9C2 cell lines, RGPP had less than 10% of GFP plasmid transfection efficiency. Collectively, RGPP is a potential nano-carrier for high-efficiency gene delivery, and needs to be further optimized for different cell lines.

Functionalized graphene oxide for anti-VEGF siRNA delivery: preparation, characterization and evaluation in vitro and in vivo

GO–PLL–SDGR/VEGF-siRNA inhibits tumor growth as a tumor targeting delivery system.

Multifunctional reduced graphene oxide coated cloths for oil/water separation and antibacterial application

Reduced graphene oxide coated cloths have been utilized for oil/water separation and antibacterial application.