Extremely High Two-Photon Absorbing Graphene Oxide for Imaging of Tumor Cells in the Second Biological Window

Graphene-Based Photodynamic Therapy and Overcoming Cancer Resistance Mechanisms: A Comprehensive Review

Photodynamic therapy (PDT) is a non-invasive therapy that has made significant progress in treating different diseases, including cancer, by utilizing new nanotechnology products such as graphene and its derivatives. Graphene-based materials have large surface area and photothermal effects thereby making them suitable candidates for PDT or photo-active drug carriers. The remarkable photophysical properties of graphene derivates facilitate the efficient generation of reactive oxygen species (ROS) upon light irradiation, which destroys cancer cells. Surface functionalization of graphene and its materials can also enhance their biocompatibility and anticancer activity. The paper delves into the distinct roles played by graphene-based materials in PDT such as photosensitizers (PS) and drug carriers while at the same time considers how these materials could be used to circumvent cancer resistance. This will provide readers with an extensive discussion of various pathways contributing to PDT inefficiency. Consequently, this comprehensive review underscores the vital roles that graphene and its derivatives may play in emerging PDT strategies for cancer treatment and other medical purposes. With a better comprehension of the current state of research and the existing challenges, the integration of graphene-based materials in PDT holds great promise for developing targeted, effective, and personalized cancer treatments.

Applications of Pristine and Functionalized Carbon Nanotubes, Graphene, and Graphene Nanoribbons in Biomedicine

This review is dedicated to a comprehensive description of the latest achievements in the chemical functionalization routes and applications of carbon nanomaterials (CNMs), such as carbon nanotubes, graphene, and graphene nanoribbons. The review starts from the description of noncovalent and covalent exohedral modification approaches, as well as an endohedral functionalization method. After that, the methods to improve the functionalities of CNMs are highlighted. These methods include the functionalization for improving the hydrophilicity, biocompatibility, blood circulation time and tumor accumulation, and the cellular uptake and selectivity. The main part of this review includes the description of the applications of functionalized CNMs in bioimaging, drug delivery, and biosensors. Then, the toxicity studies of CNMs are highlighted. Finally, the further directions of the development of the field are presented.

MoS2-based nanocomposites for cancer diagnosis and therapy

Molybdenum is a trace dietary element necessary for the survival of humans. Some molybdenum-bearing enzymes are involved in key metabolic activities in the human body (such as xanthine oxidase, aldehyde oxidase and sulfite oxidase). Many molybdenum-based compounds have been widely used in biomedical research. Especially, MoS2-nanomaterials have attracted more attention in cancer diagnosis and treatment recently because of their unique physical and chemical properties. MoS2 can adsorb various biomolecules and drug molecules via covalent or non-covalent interactions because it is easy to modify and possess a high specific surface area, improving its tumor targeting and colloidal stability, as well as accuracy and sensitivity for detecting specific biomarkers. At the same time, in the near-infrared (NIR) window, MoS2 has excellent optical absorption and prominent photothermal conversion efficiency, which can achieve NIR-based phototherapy and NIR-responsive controlled drug-release. Significantly, the modified MoS2-nanocomposite can specifically respond to the tumor microenvironment, leading to drug accumulation in the tumor site increased, reducing its side effects on non-cancerous tissues, and improved therapeutic effect. In this review, we introduced the latest developments of MoS2-nanocomposites in cancer diagnosis and therapy, mainly focusing on biosensors, bioimaging, chemotherapy, phototherapy, microwave hyperthermia, and combination therapy. Furthermore, we also discuss the current challenges and prospects of MoS2-nanocomposites in cancer treatment.

Graphene Oxide of Extra High Oxidation: A Wafer for Loading Guest Molecules

We present a new modification of graphene oxide with very high content (85 wt %) of oxygen-containing functional groups (hydroxy, epoxy, lactol, carboxyl, and carbonyl groups) that forms stable aqueous dispersion in up to 9 g·L^-1 concentration solutions. A novel faster method of the synthesis is described that produces up to 1 kg of the material and allows controlling the particle size in solution. The synthesized compound was characterized by various physicochemical methods and molecular dynamics modeling, revealing a unique structure in the form of a multilayered wafer of several sheets thick, where each sheet is highly corrugated. The ragged structure of the sheets forms pockets with hindered mobility of water that leads to the possibility of trapping guest molecules.

Graphene and its Derivatives-Based Optical Sensors

Being the first successfully prepared two-dimensional material, graphene has attracted extensive attention from researchers due to its excellent properties and extremely wide range of applications. In particular, graphene and its derivatives have displayed several ideal properties, including broadband light absorption, ability to quench fluorescence, excellent biocompatibility, and strong polarization-dependent effects, thus emerging as one of the most popular platforms for optical sensors. Graphene and its derivatives-based optical sensors have numerous advantages, such as high sensitivity, low-cost, fast response time, and small dimensions. In this review, recent developments in graphene and its derivatives-based optical sensors are summarized, covering aspects related to fluorescence, graphene-based substrates for surface-enhanced Raman scattering (SERS), optical fiber biological sensors, and other kinds of graphene-based optical sensors. Various sensing applications, such as single-cell detection, cancer diagnosis, protein, and DNA sensing, are introduced and discussed systematically. Finally, a summary and roadmap of current and future trends are presented in order to provide a prospect for the development of graphene and its derivatives-based optical sensors.

Applications of Graphene and Graphene Oxide in Smart Drug/Gene Delivery: Is the World Still Flat?

Graphene, a wonder material, has made far-reaching developments in many different fields such as materials science, electronics, condensed physics, quantum physics, energy systems, etc. Since its discovery in 2004, extensive studies have been done for understanding its physical and chemical properties. Owing to its unique characteristics, it has rapidly became a potential candidate for nano-bio researchers to explore its usage in biomedical applications. In the last decade, remarkable efforts have been devoted to investigating the biomedical utilization of graphene and graphene-based materials, especially in smart drug and gene delivery as well as cancer therapy. Inspired by a great number of successful graphene-based materials integrations into the biomedical area, here we summarize the most recent developments made about graphene applications in biomedicine. In this paper, we review the up-to-date advances of graphene-based materials in drug delivery applications, specifically targeted drug/ gene delivery, delivery of antitumor drugs, controlled and stimuli-responsive drug release, photodynamic therapy applications and optical imaging and theranostics, as well as investigating the future trends and succeeding challenges in this topic to provide an outlook for future researches.

Applications of Two-Dimensional Nanomaterials in Breast Cancer Theranostics

Breast cancer is the leading cause of cancer-related mortality among women. Early stage diagnosis and treatment of this cancer are crucial to patients' survival. In addition, it is important to avoid severe side effects during the process of conventional treatments (surgery, chemotherapy, hormonal therapy, and targeted therapy) and increase the patients' quality of life. Over the past decade, nanomaterials of all kinds have shown excellent prospects in different aspects of oncology. Among them, two-dimensional (2D) nanomaterials are unique due to their physical and chemical properties. The functional variability of 2D nanomaterials stems from their large specific surface area as well as the diversity of composition, electronic configurations, interlayer forces, surface functionalities, and charges. In this review, the current status of 2D nanomaterials in breast cancer diagnosis and therapy is reviewed. In this respect, sensing of the tumor biomarkers, imaging, therapy, and theranostics are discussed. The ever-growing 2D nanomaterials are building blocks for the development of a myriad of nanotheranostics. Accordingly, there is the possibility to explore yet novel properties, biological effects, and oncological applications.

Surface-Engineered Gold Nanoclusters with Biological Assembly-Amplified Emission for Multimode Imaging

Here, we develop bifunctional ligand-engineered gold nanoclusters (AuNCs) as signal amplifying reporters for multimode imaging. Modified streptavidin (SA) and biotin alkyl acid-based ligands were applied to AuNCs to form AuNC-SA and AuNC-biotin. The zwitterionic ligands promoted bioassembly and avoided nonspecific adsorption. The AuNCs resisted aggregation-induced quenching and showed strong emission benefited from biological self-assembly. The engineered AuNCs featured stable emission, a large two-photon absorption cross section, long fluorescence lifetime, and good biocompatibility. Thus, cell-expressed antigen-induced protein-binding events were effectively converted into signals from the biological assemble of AuNCs. We performed a comprehensive assay of specific antigens and the cell structure, through one-photon imaging, two-photon imaging, and fluorescence lifetime imaging of AuNCs in a simple, sensitive, and reliable way.

Molecular Engineering of Functional Nucleic Acid Nanomaterials toward In Vivo Applications

Recent advances in nanotechnology and engineering have generated many nanomaterials with unique physical and chemical properties. Over the past decade, numerous nanomaterials are introduced into many research areas, such as sensors for environmental monitoring, food safety, point-of-care diagnostics, and as transducers for solar energy transfer. Meanwhile, functional nucleic acids (FNAs), including nucleic acid enzymes, aptamers, and aptazymes, have attracted major attention from the biomedical community due to their unique target recognition and catalytic properties. Benefiting from the recent progress of molecular engineering strategies, the physicochemical properties of nanomaterials are endowed by the target recognition and catalytic activity of FNAs in the presence of a target analyte, resulting in numerous smart nanoprobes for diverse applications including intracellular imaging, drug delivery, in vivo imaging, and tumor therapy. This progress report focuses on the recent advances in designing and engineering FNA-based nanomaterials, highlighting the functional outcomes toward in vivo applications. The challenges and opportunities for the future translation of FNA-based nanomaterials into clinical applications are also discussed.

Designing Highly Crystalline Multifunctional Multicolor Luminescence Nanosystem for Tracking Breast Cancer Heterogeneity

Breast tumor heterogeneity is responsible for the death of ~ 40,000 women in 2017 in USA. Triple-negative breast cancers (TNBCs) are very aggressive and it is the only breast cancer subgroup still lacking effective therapeutic. As a result, early stage detection of TNBC is vital and it will have huge significant in the clinics. Driven by the need, here we report the design of highly crystalline antibody-conjugated multifunctional multicolor luminescence nanosystem derived from naturally available popular tropical fruits mango and prune, which have capability to track breast cancer heterogeneity via selective separation and accurate identification of TNBC and HER-2 (+) or ER/PR (+) breast cancer cells selectively and simultaneously. A detailed synthesis and characterization of multifunctional multicolor nanosystems from tropical fruits has been reported. Experimental results show that by changing the fruits, multicolor luminescent carbon dots (LCDs) can be developed and is mainly due to the formation of highly crystalline nano dots with different heavy metal doping and also due to the presence of different types of surface functional groups. Experimental data presented show that multifunctional multicolor nanoprobe can be used for highly selective and simultaneous capturing of targeted TNBCs, HER2(+) or ER(+) breast cancer cells and the capture efficiency can be as high as 98%. Reported data indicate that multicolor fluorescence imaging can be used for mapping hetergenous breast cancer cells simultaneously, and it can distinguish targeted TNBCs from non-targeted HER-2 (+) or ER/PR (+) breast cancer. Our finding suggests excellent possibility of designing multicolor nanosystems from natural fruits for tracking cancer heterogeneity in clinics.

Graphene Oxide as a Multifunctional Platform for Intracellular Delivery, Imaging, and Cancer Sensing

Graphene oxide (GO), the most common derivative of graphene, is an exceptional nanomaterial that possesses multiple physical properties critical for biomedical applications. GO exhibits pH-dependent fluorescence emission in the visible/near-infrared, providing a possibility of molecular imaging and pH-sensing. It is also water soluble and has a substantial platform for functionalization, allowing for the delivery of multiple therapeutics. GO physical properties are modified to enhance cellular internalization, producing fluorescent nanoflakes with low (<15%) cytotoxicity at the imaging concentrations of 15 μg/mL. As a result, at lower flake sizes GO rapidly internalizes into HeLa cells with the following 70% fluorescence based clearance at 24 h, assessed by its characteristic emission in red/near-IR. pH-dependence of GO emission is utilized to provide the sensing of acidic extracellular environments of cancer cells. The results demonstrate diminishing green/red (550/630 nm) fluorescence intensity ratios for HeLa and MCF-7 cancer cells in comparison to HEK-293 healthy cells suggesting a potential use of GO as a non-invasive optical sensor for cancer microenvironments. The results of this work demonstrate the potential of GO as a novel multifunctional platform for therapeutic delivery, biological imaging and cancer sensing.

Carbon Nanomaterials in Optical Detection

Owing to their unique optical, electronic, mechanical, and chemical properties, flexible chemical modification, large surface coverage and ready cellular uptake, various carbon nanomaterials such as carbon nanotubes (CNTs), graphene and its derivatives, carbon dots (CDs), graphene quantum dots, fullerenes, carbon nanohorns (CNHs) and carbon nano-onions (CNOs), have been widely explored for use in optical detection. Most of them are based on fluorescence changes. In this chapter, we will focus on carbon nanomaterials-based optical detection applications, mainly including fluorescence sensing and bio-imaging. Moreover, perspectives on future exploration of carbon nanomaterials for optical detection are also given.

Nonlinear Optics with 2D Layered Materials

2D layered materials (2DLMs) are a subject of intense research for a wide variety of applications (e.g., electronics, photonics, and optoelectronics) due to their unique physical properties. Most recently, increasing research efforts on 2DLMs are projected toward the nonlinear optical properties of 2DLMs, which are not only fascinating from the fundamental science point of view but also intriguing for various potential applications. Here, the current state of the art in the field of nonlinear optics based on 2DLMs and their hybrid structures (e.g., mixed-dimensional heterostructures, plasmonic structures, and silicon/fiber integrated structures) is reviewed. Several potential perspectives and possible future research directions of these promising nanomaterials for nonlinear optics are also presented.

Leveraging Engineering of Indocyanine Green-Encapsulated Polymeric Nanocomposites for Biomedical Applications

In recent times, photo-induced therapeutics have attracted enormous interest from researchers due to such attractive properties as preferential localization, excellent tissue penetration, high therapeutic efficacy, and minimal invasiveness, among others. Numerous photosensitizers have been considered in combination with light to realize significant progress in therapeutics. Along this line, indocyanine green (ICG), a Food and Drug Administration (FDA)-approved near-infrared (NIR, >750 nm) fluorescent dye, has been utilized in various biomedical applications such as drug delivery, imaging, and diagnosis, due to its attractive physicochemical properties, high sensitivity, and better imaging view field. However, ICG still suffers from certain limitations for its utilization as a molecular imaging probe in vivo, such as concentration-dependent aggregation, poor in vitro aqueous stability and photodegradation due to various physicochemical attributes. To overcome these limitations, much research has been dedicated to engineering numerous multifunctional polymeric composites for potential biomedical applications. In this review, we aim to discuss ICG-encapsulated polymeric nanoconstructs, which are of particular interest in various biomedical applications. First, we emphasize some attractive properties of ICG (including physicochemical characteristics, optical properties, metabolic features, and other aspects) and some of its current limitations. Next, we aim to provide a comprehensive overview highlighting recent reports on various polymeric nanoparticles that carry ICG for light-induced therapeutics with a set of examples. Finally, we summarize with perspectives highlighting the significant outcome, and current challenges of these nanocomposites.

Fluorescence and Sensing Applications of Graphene Oxide and Graphene Quantum Dots: A Review

Graphene oxide and graphene quantum dots are attractive fluorophores that are inexpensive, nontoxic, photostable, water-soluble, biocompatible, and environmentally friendly. They find extensive applications in fluorescent biosensors and chemosensors, in which they serve as either fluorophores or quenchers. As fluorophores, they display tunable photoluminescence emission and the "giant red-edge effect". As quenchers, they exhibit a remarkable quenching efficiency through either electron transfer or Förster resonance energy transfer (FRET) process. In this review, the origin of fluorescence and the mechanism of excitation wavelength-dependent fluorescence of graphene oxide and graphene quantum dots are discussed. Sensor design strategies based on graphene oxide and graphene quantum dots are presented. The applications of these sensors in health care, the environment, agriculture, and food safety are highlighted.

Two-Photon Fluorescent Molybdenum Disulfide Dots for Targeted Prostate Cancer Imaging in the Biological II Window

Molybdenum disulfide (MoS2) quantum dots (QDs) derived from this two-dimensional (2D) transition metal dichalcogenide are emerging zero-dimensional materials that possess very good optical properties. Bioimaging using light in the biological II window (950-1350 nm) is a next-generation approach that will allow clinicians to achieve deeper tissue imaging with better image contrast and reduced phototoxicity and photobleaching. This article reports the development of a water-soluble, zero-dimensional antibody-conjugated transition metal dichalcogenide MoS2 QD-based two-photon luminescence (TPL) probe for the targeted bioimaging of cancer cells in the biological II window. The data indicates that MoS2 QDs exhibit an extremely high two-photon absorption cross-section (σ = 58960 GM) and two-photon brightness (4.7 × 103 GM) because of the quantum confinement and edge effects. Experimental data show that anti-PSMA antibody-attached MoS2 QDs can be used for selective two-photon imaging of live prostate cancer cells using 1064 nm light because of the high two-photon brightness, very good photostability, and very good biocompatibility of these MoS2 QDs. The data demonstrate that the bioconjugated MoS2 QDs can distinguish targeted and nontargeted cells. This study illuminates the high two-photon brightness mechanism of MoS2 QDs and provides a zero-dimensional transition metal dichalcogenide-based selective TPL agent for high-efficiency live cell imaging.

Recent progress on the development of anisotropic gold nanoparticles: Design strategies and growth mechanism

This review summarizes recent advances on design strategies for shape-controlled anisotropic gold nanoparticles. Detailed chemical mechanism has been discussed to understand the anisotropic growth. The effect of various chemical parameters and surface facets for the formation of different shaped anisotropic nanoparticles have been addressed.

Microwave Synthesis of Chitosan Capped Silver-Dysprosium Bimetallic Nanoparticles: A Potential Nanotheranosis Device

Accurate imaging of the structural and functional state of biological targets is a critical task. To amend paucities associated with individual imaging, there is high interest to develop a multifunctional theranostic devices for cancer diagnosis and therapy. Herein, chitosan coated silver/dysprosium bimetallic nanoparticles (BNPs) were synthesized through a green chemistry route and characterization results inferred that the BNPs are crystalline, spherical, and of size ∼10 nm. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray photoelectron spectroscopy (XPS) confirm the reduced metallic states of Ag and Dy in nanoparticles. These BNPs demonstrate high emission in a second near-infrared (NIR-II, 1000-1400 nm) biological window on excitation at 808 nm. Moreover, magnetization and magnetic resonance imaging (MRI) studies perceive the inherent paramagnetic features of Dy component that displays dark T₂ contrast and high relaxivity. Due to high X-ray attenuation effect, BNPs exhibit better Hounsfield unit (HU) value than the reported contrast agents. BNPs unveil good biocompatibility and also express sturdy therapeutic effect in HeLa cells when tethered with doxorubicin.

In vitro and in vivo comparison of the immunotoxicity of single- and multi-layered graphene oxides with or without pluronic F-127

Graphene oxide (GO) has been a focus of research in the fields of electronics, energy, and biomedicine, including drug delivery. Thus, single- and multi-layered GO (SLGO and MLGO) have been produced and investigated. However, little information on their toxicity and biocompatibility is available. In the present study, we performed a comprehensive study of the size- and dose-dependent toxicity of GOs in the presence or absence of Pluronic F-127 on THP-1 cells by examining their viability, membrane integrity, levels of cytokine and ROS production, phagocytosis, and cytometric apoptosis. Moreover, as an extended study, a toxicity evaluation in the acute and chronic phases was performed in mice via intravenous injection of the materials. GOs exhibited dose- and size-dependent toxicity. Interestingly, SLGO induced ROS production to a lesser extent than MLGO. Cytometric analysis indicated that SLGO induced necrosis and apoptosis to a lesser degree than MLGO. In addition, cell damage and IL-1β production were influenced by phagocytosis. A histological animal study revealed that GOs of various sizes induced acute and chronic damage to the lung and kidney in the presence or absence of Pluronic F-127. These results will facilitate studies of GO prior to its biomedical application.

Haber Process Made Efficient by Hydroxylated Graphene: Ab Initio Thermochemistry and Reactive Molecular Dynamics

The Haber-Bosch process is the main industrial method for producing ammonia from diatomic nitrogen and hydrogen. We use a combination of ab initio thermochemical analysis and reactive molecular dynamics to demonstrate that a significant increase in the ammonia production yield can be achieved using hydroxylated graphene and related species. Exploiting the polarity difference between N2/H2 and NH3, as well as the universal proton acceptor behavior of NH3, we demonstrate a strong shift of the equilibrium of the Haber-Bosch process toward ammonia (ca. 50 kJ mol(-1) enthalpy gain and ca. 60-70 kJ mol(-1) free energy gain). The modified process is of significant importance to the chemical industry.

Multimodal Nonlinear Optical Imaging of Live Cells Using Plasmon-Coupled DNA-Mediated Gold Nanoprism Assembly

Multiphoton excitation microscopy techniques are the emerging nonlinear optical (NLO) imaging methods to watch the biological world due its ability to penetrate deep into living tissues. Driven by the need to develop multimodal NLO imaging probe, current article reports the design of DNA-mediated gold nanoprisms assembly based optical antennas to enhance multiphoton imaging capability in biological II window. Reported experimental data show a unique way to enhance second harmonic generation (SHG) and two-photon fluorescence (TPF) properties by several orders of magnitudes via plasmon coupled organization into gold nanoprism assembly structures. Experimental and theoretical modeling data using finite difference time domain (FDTD) simulations indicate that huge enhancement of SHG and TPF properties are mainly due to the electric quadrupole contribution and electric field enhancement. Using 1100 nm biological II window light, reported results demonstrated that antibody conjugated assembly structures are capable of exhibiting highly selective and very bright multimodal SHG and TPF imaging of human Hep G2 liver cancer cells.

Applications of graphene and its derivatives in intracellular biosensing and bioimaging

Graphene has a unique planar structure, as well as excellent electronic properties, and has attracted a great deal of interest from scientists.

Exploring the photothermal hot spots of graphene in the first and second biological window to inactivate cancer cells and pathogens

Study of the photothermal capability and inactivation of cancer cells and pathogens by biocompatible RGOPAA under the first and second biological window.

Hybrid Theranostic Platform for Second Near-IR Window Light Triggered Selective Two-Photon Imaging and Photothermal Killing of Targeted Melanoma Cells

Despite advances in the medical field, even in the 21st century cancer is one of the leading causes of death for men and women in the world. Since the second near-infrared (NIR) biological window light between 950 and 1350 nm offers highly efficient tissue penetration, the current article reports the development of hybrid theranostic platform using anti-GD2 antibody attached gold nanoparticle (GNP) conjugated, single-wall carbon nanotube (SWCNT) for second near-IR light triggered selective imaging and efficient photothermal therapy of human melanoma cancer cell. Reported results demonstrate that due to strong plasmon-coupling, two-photon luminescence (TPL) intensity from theranostic GNP attached SWCNT materials is 6 orders of magnitude higher than GNP or SWCNT alone. Experimental and FDTD simulation data indicate that the huge enhancement of TPL intensity is mainly due to strong resonance enhancement coupled with the stronger electric field enhancement. Due to plasmon coupling, the theranostic material serves as a local nanoantennae to enhance the photothermal capability via strong optical energy absorption. Reported data show that theranostic SWCNT can be used for selective two-photon imaging of melanoma UACC903 cell using 1100 nm light. Photothermal killing experiment with 1.0 W/cm(2) 980 nm laser light demonstrates that 100% of melanoma UACC903 cells can be killed using theranostic SWCNT bind melanoma cells after just 8 min of exposure. These results demonstrate that due to plasmon coupling, the theranostic GNP attached SWCNT material serves as a two-photon imaging and photothermal source for cancer cells in biological window II.

Multifunctional biocompatible graphene oxide quantum dots decorated magnetic nanoplatform for efficient capture and two-photon imaging of rare tumor cells

Circulating tumor cells (CTCs) are extremely rare cells in blood containing billions of other cells. The selective capture and identification of rare cells with sufficient sensitivity is a real challenge. Driven by this need, this manuscript reports the development of a multifunctional biocompatible graphene oxide quantum dots (GOQDs) coated, high-luminescence magnetic nanoplatform for the selective separation and diagnosis of Glypican-3 (GPC3)-expressed Hep G2 liver cancer tumor CTCs from infected blood. Experimental data show that an anti-GPC3-antibody-attached multifunctional nanoplatform can be used for selective Hep G2 hepatocellular carcinoma tumor cell separation from infected blood containing 10 tumor cells/mL of blood in a 15 mL sample. Reported data indicate that, because of an extremely high two-photon absorption cross section (40530 GM), an anti-GPC3-antibody-attached GOQDs-coated magnetic nanoplatform can be used as a two-photon luminescence platform for selective and very bright imaging of a Hep G2 tumor cell in a biological transparency window using 960 nm light. Experimental results with nontargeted GPC3(-) and SK-BR-3 breast cancer cells show that multifunctional-nanoplatform-based cell separation, followed by two-photon imaging, is highly selective for Hep G2 hepatocellular carcinoma tumor cells.

Aptamer-conjugated theranostic hybrid graphene oxide with highly selective biosensing and combined therapy capability

Cancer is a life-threatening disease, which is rapidly becoming a global pandemic. Driven by this need, here we report for the first time an aptamer-conjugated theranostic magnetic hybrid graphene oxide-based assay for highly sensitive tumor cell detection from blood samples with combined therapy capability. AGE-aptamer-conjugated theranostic magnetic nanoparticle-attached hybrid graphene oxide was developed for highly selective detection of tumor cells from infected blood samples. Experimental data indicate that hybrid graphene can be used as a multicolor luminescence platform for selective imaging of G361 human malignant melanoma cancer cells. The reported results have also shown that indocyanine green (ICG)-bound AGE-aptamer-attached hybrid graphene oxide is capable of combined synergistic photothermal and photodynamic treatment of cancer. Targeted combined therapeutic treatment using 785 nm near-infrared (NIR) light indicates that the multimodal therapeutic treatment is highly effective for malignant melanoma cancer therapy. The reported data show that this aptamer-conjugated theranostic graphene oxide-based assay has exciting potential for improving cancer diagnosis and treatment.

Primary hepatocyte imaging by multiphoton luminescent graphene quantum dots

Water soluble GQDs were systematically characterized as a multiphoton fluorophore and a cell imaging probe. When mouse primary hepatocytes were incubated with GQDs, no significant cytotoxicity was observed up to the treatment concentration of 100 μg ml(-1). Using these GQDs, mouse primary hepatocytes were successfully imaged by multiphoton fluorescence.

Aptamer-conjugated graphene oxide membranes for highly efficient capture and accurate identification of multiple types of circulating tumor cells

Tumor metastasis is responsible for 1 in 4 deaths in the United States. Though it has been well-documented over past two decades that circulating tumor cells (CTCs) in blood can be used as a biomarker for metastatic cancer, there are enormous challenges in capturing and identifying CTCs with sufficient sensitivity and specificity. Because of the heterogeneous expression of CTC markers, it is now well understood that a single CTC marker is insufficient to capture all CTCs from the blood. Driven by the clear need, this study reports for the first time highly efficient capture and accurate identification of multiple types of CTCs from infected blood using aptamer-modified porous graphene oxide membranes. The results demonstrate that dye-modified S6, A9, and YJ-1 aptamers attached to 20-40 μm porous garphene oxide membranes are capable of capturing multiple types of tumor cells (SKBR3 breast cancer cells, LNCaP prostate cancer cells, and SW-948 colon cancer cells) selectively and simultaneously from infected blood. Our result shows that the capture efficiency of graphene oxide membranes is ~95% for multiple types of tumor cells; for each tumor concentration, 10 cells are present per milliliter of blood sample. The selectivity of our assay for capturing targeted tumor cells has been demonstrated using membranes without an antibody. Blood infected with different cells also has been used to demonstrate the targeted tumor cell capturing ability of aptamer-conjugated membranes. Our data also demonstrate that accurate analysis of multiple types of captured CTCs can be performed using multicolor fluorescence imaging. Aptamer-conjugated membranes reported here have good potential for the early diagnosis of diseases that are currently being detected by means of cell capture technologies.

Antimicrobial Peptide-Conjugated Graphene Oxide Membrane for Efficient Removal and Effective Killing of Multiple Drug Resistant Bacteria

According to the World Health Organization (WHO), multiple drug-resistant (MDR) bacterial infection is a top threat to human health. Since bacteria evolve to resist antibiotics faster than scientists can develop new classes of drugs, the development of new materials which can be used, not only for separation, but also for effective disinfection of drug resistant pathogens is urgent. Driven by this need, we report for the first time the development of a nisin antimicrobial peptide conjugated, three dimensional (3D) porous graphene oxide membrane for identification, effective separation, and complete disinfection of MDR methicillin-resistant Staphylococcus aureus (MRSA) pathogens from water. Experimental data show that due to the size differences, MRSA is captured by the porous membrane, allowing only water to pass through. SEM, TEM, and fluorescence images confirm that pathogens are captured by the membrane. RT-PCR data with colony counting indicate that almost 100% of MRSA can be removed and destroyed from the water sample using the developed membrane. Comparison of MDR killing data between nisin alone, the graphene oxide membrane and the nisin attached graphene oxide membrane demonstrate that the nisin antimicrobial peptide attached graphene oxide membrane can dramatically enhance the possibility of destroying MRSA via a synergestic effect due to the multimodal mechanism.

Accurate Identification and Selective Removal of Rotavirus Using a Plasmonic-Magnetic 3D Graphene Oxide Architecture

According to the World Health Organization, even in the 21st century, more than one million children die each year due to the rotavirus contamination of drinking water. Therefore, accurate identification and removal of rotavirus are very important to save childrens' lives. Driven by the need, in this Letter, we report for the first time highly selective identification and removal of rotavirus from infected water using a bioconjugated hybrid graphene oxide based three-dimensional (3D) solid architecture. Experimental results show that due to the presence of a high intensity of "hot spots" in the 3D network, an antibody-attached 3D plasmonic-magnetic architecture can be used for accurate identification of rotavirus using surface-enhanced Raman spectroscopy (SERS). Reported data demonstrate that the antibody-attached 3D network binds strongly with rotavirus and is capable of highly efficient removal of rotavirus, which has been confirmed by SERS, fluorescence imaging, and enzyme-linked immunosorbent assay (ELISA) data. We discuss a possible mechanism for accurate identification and efficient removal of rotavirus from infected drinking water.