Designing a Novel Polymer Electrolyte for Improving the Electrode/Electrolyte Interface in Flexible All-Solid-State Electrical Double-Layer Capacitors.

A novel copolymer, polyurethane-poly(acrylic acid) (PAA), is successfully synthesized from poly(acrylic acid) (PAA) backbone cross-linked with waterborne polyurethane (WPU). This sticky polymer, which is neutralized with 1 M KOH and then soaked in 1 M KOH (denoted as WPU-PAAK-K), provides an ionic conductivity greater than 10-2 S cm-1 and acts as a gel electrolyte perfectly improving the electrode/electrolyte interfaces in a flexible all-solid-state electrical double-layer capacitor (EDLC). The PAA backbone chains in the copolymer increase the amount of carboxyl groups and promote the segmental motion. The carboxyl groups enhance the water-uptake capacity, which facilitates the ion transport and promotes the ionic conductivity. The cross-linked agent, WPU chains, effectively maintains the rich water content and provides mechanical stickiness to bind two electrodes together. An acid-treated carbon paper (denoted as ACP) combining with such a gel polymer electrolyte demonstrates excellent capacitive behavior with a high areal capacitance of 211.6 mF cm-2 at 10 mV s-1. A full cell consisting of ACP/WPU-PAAK-K/ACP displays a low equivalent series resistance of 0.44 Ω from the electrochemical impedance spectroscopic results. An all-solid-state ACP/WPU-PAAK-K/ACP EDLC provides an areal specific capacitance of 94.6 mF cm-2 at 1 mA cm-2. This device under 180° bending shows a capacitance retention over 90%, revealing its remarkable flexibility.

1,3-Bis(2-chloroethyl)-1-nitrosourea-loaded bovine serum albumin nanoparticles with dual magnetic resonance-fluorescence imaging for tracking of chemotherapeutic agents.

To date, knowing how to identify the location of chemotherapeutic agents in the human body after injection is still a challenge. Therefore, it is urgent to develop a drug delivery system with molecular imaging tracking ability to accurately understand the distribution, location, and concentration of a drug in living organisms. In this study, we developed bovine serum albumin (BSA)-based nanoparticles (NPs) with dual magnetic resonance (MR) and fluorescence imaging modalities (fluorescein isothiocyanate [FITC]-BSA-Gd/1,3-bis(2-chloroethyl)-1-nitrosourea [BCNU] NPs) to deliver BCNU for inhibition of brain tumor cells (MBR 261-2). These BSA-based NPs are water dispersible, stable, and biocompatible as confirmed by XTT cell viability assay. In vitro phantoms and in vivo MR and fluorescence imaging experiments show that the developed FITC-BSA-Gd/BCNU NPs enable dual MR and fluorescence imaging for monitoring cellular uptake and distribution in tumors. The T1 relaxivity (R1) of FITC-BSA-Gd/BCNU NPs was 3.25 mM(-1) s(-1), which was similar to that of the commercial T1 contrast agent (R1 =3.36 mM(-1) s(-1)). The results indicate that this multifunctional drug delivery system has potential bioimaging tracking of chemotherapeutic agents ability in vitro and in vivo for cancer therapy.

Non-invasive screening for early Alzheimer's disease diagnosis by a sensitively immunomagnetic biosensor.

Amyloid-beta peptide 1-42 (Aß42) is considered as a reliable biomarker for the early diagnosis of Alzheimer's disease (AD). Thus, it is urgent to develop a simple and efficient method for the detection of Aß42. In this work, a reusable biosensor based on magnetic nitrogen-doped graphene (MNG) modified Au electrode for the detection of Aß42 has been developed. The antibodies of Aß 1-28 (Aßab) are used as the specific biorecognition element for Aß42 that were conjugated on the surface of MNG. In the presence of magnetic nanoparticles on MNG, the electrode coating material, the biosensor can be quickly constructed, without requiring an electrode drying process, which reduce the analysis time and is convenient for proceeding to detection. The reusable biosensor with good reproducibility and stability was linear within the range from 5 pg mL(-1) to 800 pg mL(-1), covering the cut-off level of Aß42 and a detection limit of 5 pg mL(-1) had been achieved. Furthermore, the fabricated biosensor for Aß42 detection not only improves the detection performance but also reduces the cost and shortens the response time, demonstrating its potential in diagnosing applications.

The Two-Dimensional Nanocomposite of Molybdenum Disulfide and Nitrogen-Doped Graphene Oxide for Efficient Counter Electrode of Dye-Sensitized Solar Cells.

In this study, we reported the synthesis of the two-dimensional (2D) nanocomposite of molybdenum disulfide and nitrogen-doped graphene oxide (MoS2/nGO) as a platinum-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy were used to examine the characteristics of the 2D nanocomposite of MoS2/nGO. The cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and the Tafel polarization measurements were carried out to examine the electrocatalytic abilities. XPS and Raman results showed the 2D behaviors of the prepared nanomaterials. HRTEM micrographs showed the direct evidence of the 2D nanocomposite of MoS2/nGO. The results of electrocatalytic examinations indicated the MoS2/nGO owning the low charge transfer resistance, high electrocatalytic activity, and fast reaction kinetics for the reduction of triiodide to iodide on the electrolyte-electrode interface. The 2D nanocomposite of MoS2/nGO combined the advantages of the high specific surface of nGO and the plenty edge sites of MoS2 and showed the promoted properties different from those of their individual constituents to create a new outstanding property. The DSSC with MoS2/nGO nanocomposite CE showed a photovoltaic conversion efficiency (PCE) of 5.95 % under an illumination of AM 1.5 (100 mW/cm(2)), which was up to 92.2 % of the DSSC with the conventional platinum (Pt) CE (PCE = 6.43 %). These results reveal the potential of the MoS2/nGO nanocomposite in the use of low-cost, scalable, and efficient Pt-free CEs for DSSCs.

Enhanced Electrochemical Catalytic Efficiencies of Electrochemically Deposited Platinum Nanocubes as a Counter Electrode for Dye-Sensitized Solar Cells.

Platinum nanocubes (PtNCs) were deposited onto a fluorine-doped tin oxide glass by electrochemical deposition (ECD) method and utilized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). In this study, we controlled the growth of the crystalline plane to synthesize the single-crystal PtNCs at room temperature. The morphologies and crystalline nanostructure of the ECD PtNCs were examined by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The surface roughness of the ECD PtNCs was examined by atomic force microscopy. The electrochemical properties of the ECD PtNCs were analyzed by cyclic voltammetry, Tafel polarization, and electrochemical impedance spectra. The Pt loading was examined by inductively coupled plasma mass spectrometry. The DSSCs were assembled via an N719 dye-sensitized titanium dioxide working electrode, an iodine-based electrolyte, and a CE. The photoelectric conversion efficiency (PCE) of the DSSCs with the ECD PtNC CE was examined under the illumination of AM 1.5 (100 mWcm(-2)). The PtNCs in this study presented a single-crystal nanostructure that can raise the electron mobility to let up the charge-transfer impedance and promote the charge-transfer rate. In this work, the electrocatalytic mass activity (MA) of the Pt film and PtNCs was 1.508 and 4.088 mAmg(-1), respectively, and the MA of PtNCs was 2.71 times than that of the Pt film. The DSSCs with the pulse-ECD PtNC CE showed a PCE of 6.48 %, which is higher than the cell using the conventional Pt film CE (a PCE of 6.18 %). In contrast to the conventional Pt film CE which is fabricated by electron beam evaporation method, our pulse-ECD PtNCs maximized the Pt catalytic properties as a CE in DSSCs. The results demonstrated that the PtNCs played a good catalyst for iodide/triiodide redox couple reactions in the DSSCs and provided a potential strategy for electrochemical catalytic applications.

Effect of covalent modification of graphene nanosheets on the electrical property and electromagnetic interference shielding performance of a water-borne polyurethane composite.

Flexible and lightweight graphene nanosheet (GN)/waterborne polyurethane (WPU) composites which exhibit high electrical conductivity and electromagnetic shielding performance were prepared. Covalently modifying GNs with aminoethyl methacrylate (AEMA; AEMA-GNs) through free radical polymerization effectively inhibited the restacking and aggregation of the GNs because of the -NH3(+) functional groups grafted on the AEMA-GNs. Moreover, the AEMA-GNs exhibited high compatibility with a WPU matrix with grafted sulfonated functional groups because of the electrostatic attraction, which caused the AEMA-GNs to homogeneously disperse in the WPU matrix. This homogeneous distribution enabled the GNs to form electrically conductive networks. Furthermore, AEMA-GNs with different amounts of AEMA segments were introduced into the WPU matrix, and the effects of the surface chemistry of the GNs on the electrical conductivity and EMI shielding performance of composites were investigated. AEMA-GN/WPU composites with a GN loading of 5 vol % exhibited remarkable electrical conductivity (approximately 43.64 S/m) and EMI shielding effectiveness (38 dB) over the frequency of 8.2 to 12.4 GHz.

Effects of activated carbon characteristics on the electrosorption capacity of titanium dioxide/activated carbon composite electrode materials prepared by a microwave-assisted ionothermal synthesis method.

Titanium dioxide (TiO2)/ activated carbon (AC) composite materials, as capacitive deionization electrodes, were prepared by a two-step microwave-assisted ionothermal synthesis method. The electrosorption capacity of the composite electrodes was studied and the effects of AC characteristics were explored. These effects were investigated by multiple analytical techniques, including X-ray photoelectron spectroscopy, thermogravimetry analysis and electrochemical impedance spectroscopy, etc. The experimental results indicated that the electrosorption capacity of the TiO2/AC composite electrode is dependent on the characteristics of AC including the pore structure and the surface property. An enhancement in electrosorption capacity was observed for the TiO2/AC composite electrode prepared from the AC with higher mesopore content and less hydrophilic surface. This enhancement is due to the deposition of anatase TiO2 with suitable amount of Ti-OH. On the other hand, a decline in electrosorption capacity was observed for the TiO2/AC composite electrode prepared from the AC with higher micropore content and highly hydrophilic surface. High content of hydrogen bond complex formed between the functional group on hydrophilic surface with H2O, which will slow down the TiO2 precursor-H2O reaction. In such situation, the effect of TiO2 becomes unfavorable as the loading amount of TiO2 is less and the micropore can also be blocked.

A reusable magnetic graphene oxide-modified biosensor for vascular endothelial growth factor detection in cancer diagnosis.

Early cancer diagnosis is critical for the prevention of metastasis. However, simple and efficient methods are needed to improve the diagnosis and evaluation of cancer. Here, we propose a reusable biosensor based on a magnetic graphene oxide (MGO)-modified Au electrode to detect vascular endothelial growth factor (VEGF) in human plasma for cancer diagnosis. In this biosensor, Avastin is used as the specific biorecognition element, and MGO is used as the carrier for Avastin loading. The use of MGO enables rapid purification due to its magnetic properties, which prevents the loss of bioactivity. Moreover, the biosensor can be constructed quickly, without requiring a drying process, which is convenient for proceeding to detection. Our reusable biosensor provides the appropriate sensitivity for clinical diagnostics and has a wide range of linear detection, from 31.25-2000 pg mL(-1), compared to ELISA analysis. In addition, in experiments with 100% serum from clinical samples, readouts from the sensor and an ELISA for VEGF showed good correlation within the limits of the ELISA kit. The relative standard deviation (RSD) of the change in current (ΔC) for reproducibility of the Au biosensor was 2.36% (n=50), indicating that it can be reused with high reproducibility. Furthermore, the advantages of the Avastin-MGO-modified biosensor for VEGF detection are that it provides an efficient detection strategy that not only improves the detection ability but also reduces the cost and decreases the response time by 10-fold, indicating its potential as a diagnosis product.

Polyethylene glycol-coated graphene oxide attenuates antigen-specific IgE production and enhanced antigen-induced T-cell reactivity in ovalbumin-sensitized BALB/c mice.

BACKGROUND: Graphene oxide (GO) is a promising nanomaterial for potential application in the versatile field of biomedicine. Graphene-based nanomaterials have been reported to modulate the functionality of immune cells in culture and to induce pulmonary inflammation in mice. Evidence pertaining to the interaction between graphene-based nanomaterials and the immune system in vivo remains scarce. The present study investigated the effect of polyethylene glycol-coated GO (PEG-GO) on antigen-specific immunity in vivo. METHODS: BALB/c mice were intravenously administered with a single dose of PEG-GO (0.5 or 1 mg/kg) 1 hour before ovalbumin (OVA) sensitization, and antigen-specific antibody production and splenocyte reactivity were measured 7 days later. RESULTS: Exposure to PEG-GO significantly attenuated the serum level of OVA-specific immunoglobulin E. The production of interferon-γ and interleukin-4 by splenocytes restimulated with OVA in culture was enhanced by treatment with PEG-GO. In addition, PEG-GO augmented the metabolic activity of splenocytes restimulated with OVA but not with the T-cell mitogen concanavalin A. CONCLUSION: Collectively, these results demonstrate that systemic exposure to PEG-GO modulates several aspects of antigen-specific immune responses, including the serum production of immunoglobulin E and T-cell functionality.

Effect of octa(aminophenyl) polyhedral oligomeric silsesquioxane functionalized graphene oxide on the mechanical and dielectric properties of polyimide composites.

An effective method is proposed to prepare octa(aminophenyl) silsesquioxane (OAPS) functionalized graphene oxide (GO) reinforced polyimide (PI) composites with a low dielectric constant and ultrastrong mechanical properties. The amine-functionalized surface of OAPS-GO is a versatile starting platform for in situ polymerization, which promotes the uniform dispersion of OAPS-GO in the PI matrix. Compared with GO/PI composites, the strong interfacial interaction between OAPS-GO and the PI matrix through covalent bonds facilitates a load transfer from the PI matrix to the OAPS-GO. The OAPS-GO/PI composite film with 3.0 wt % OAPS-GO exhibited an 11.2-fold increase in tensile strength, and a 10.4-fold enhancement in tensile modulus compared with neat PI. The dielectric constant (D(k)) decreased with the increasing content of 2D porous OAPS-GO, and a D(k) value of 1.9 was achieved.

Lightweight and flexible reduced graphene oxide/water-borne polyurethane composites with high electrical conductivity and excellent electromagnetic interference shielding performance.

In this study, we developed a simple and powerful method to fabricate flexible and lightweight graphene-based composites that provide high electromagnetic interference (EMI) shielding performance. Electrospun waterborne polyurethane (WPU) that featured sulfonate functional groups was used as the polymer matrix, which was light and flexible. First, graphene oxide (GO)/WPU composites were prepared through layer-by-layer (L-b-L) assembly of two oppositely charged suspensions of GO, the cationic surfactant (didodecyldimethylammonium bromide, DDAB)-adsorbed GO and intrinsic negatively charged GO, depositing on the negatively charged WPU fibers. After the L-b-L assembly cycles, the GO bilayers wrapped the WPU fiber matrix completely and revealed fine connections guided by the electrospun WPU fibers. Then, we used hydroiodic acid (HI) to obtain highly reduced GO (r-GO)/WPU composites, which exhibited substantially enhanced electrical conductivity (approximately 16.8 S/m) and, moreover, showed a high EMI-shielding effectiveness (approximately 34 dB) over the frequency range from 8.2 to 12.4 GHz.

Gadolinium-functionalized nanographene oxide for combined drug and microRNA delivery and magnetic resonance imaging.

The delivery of anti-cancer therapeutics to tumors at clinically effective concentrations, while avoiding nonspecific toxicity, remains a major challenge for cancer treatment. Here we present nanoparticles of poly(amidoamine) dendrimer-grafted gadolinium-functionalized nanographene oxide (Gd-NGO) as effective carriers to deliver both chemotherapeutic drugs and highly specific gene-targeting agents such as microRNAs (miRNAs) to cancer cells. The positively charged surface of Gd-NGO was capable of simultaneous adsorption of the anti-cancer drug epirubicin (EPI) and interaction with negatively charged Let-7g miRNA. Using human glioblastoma (U87) cells as a model, we found that this conjugate of Let-7g and EPI (Gd-NGO/Let-7g/EPI) not only exhibited considerably higher transfection efficiency, but also induced better inhibition of cancer cell growth than Gd-NGO/Let-7g or Gd-NGO/EPI. The concentration of Gd-NGO/Let-7g/EPI required for 50% inhibition of cellular growth (IC50) was significantly reduced (to the equivalent of 1.3 µg/mL EPI) compared to Gd-NGO/EPI (3.4 µg/mL EPI). In addition, Gd-NGO/Let-7g/EPI could be used as a contrast agent for magnetic resonance imaging to identify the location and extent of blood-brain barrier opening and quantitate drug delivery to tumor tissues. These results suggest that Gd-NGO/Let-7g/EPI may be a promising non-viral vector for chemogene therapy and molecular imaging diagnosis in future clinical applications.

EGRF conjugated PEGylated nanographene oxide for targeted chemotherapy and photothermal therapy.

Low accumulation of chemotherapeutic agent in tumor tissue and multidrug resistance (MDR) present a major obstacle to curing cancer treatment. Therefore, how to combine several therapeutics in one system is a key issue to overcome the problem. Here, we demonstrate epidermal growth factor receptor (EGFR) antibody-conjugated PEGylated nanographene oxide (PEG-NGO) to carry epirubicin (EPI) for tumor targeting and triple-therapeutics (growth signal blocking, chemotherapy, photothermal therapy) in tumor treatment. This synergistic targeted treatment simultaneously enhances the local drug concentration (6.3-fold) and performs the ultra-efficient tumor suppression to significantly prolong the mice survival (over the course of 50 days).

Thermally conductive and electrically insulating epoxy nanocomposites with thermally reduced graphene oxide-silica hybrid nanosheets.

We herein report on the preparation of epoxy nanocomposites, which had enhanced thermal conductivities but were still electrical insulators, incorporating hybrid nanosheets (NSs) with sandwich structures composed of thermally reduced graphene oxide (TRGO) and silica. The silica layer covered the surface of the TRGO, hindering electrical conduction and effectively forming a 3D phonon transport channel that had a unique effect on the electrical and thermal properties of the epoxy matrix. A 1 wt% TRGO-silica NS epoxy nanocomposite maintained an electrical resistivity of 2.96 × 10(11)Ω cm, and its thermal conductivity was 0.322 W m(-1) K(-1), which is 61% higher than the conductivity of an epoxy nanocomposite without TRGO-silica NSs (0.2 W m(-1) K(-1)).

Non-invasive synergistic treatment of brain tumors by targeted chemotherapeutic delivery and amplified focused ultrasound-hyperthermia using magnetic nanographene oxide.

The combination of chemo-thermal therapy is the best strategy to ablate tumors, but how to heat deep tumor tissues effectively without side-damage is a challenge. Here, a systemically delivered nanocarrier is designed with multiple advantages, including superior heat absorption, highly efficient hyperthermia, high drug capacity, specific targeting ability, and molecular imaging, to achieve both high antitumor efficacy and effective amplification of hyperthermia with minimal side effects.

Effects of multiwalled carbon nanotubes functionalization on the morphology and mechanical and thermal properties of carbon fiber/vinyl ester composites.

Multiwalled carbon nanotube (MWCNT)/carbon fiber (CF)/vinyl ester (VE) laminate composites have been fabricated in this study. Pristine MWCNTs were treated with acid solution, which formed numerous oxygen-containing functional groups onto their surface, resulting in COOH-MWCNTs. Thereafter, acrylic functional groups were grafted onto the COOH-MWCNTs to generate acryl-MWCNTs. Three types of MWCNTs (pristine MWCNTs, COOH-MWCNTs, and acryl-MWCNTs) were used to reinforce the CF/VE-based composites. The dispersion of MWCNTs in the VE matrix and the interfacial interaction between MWCNTs and the VE matrix were investigated. Thereafter, the individual reinforcement efficiencies of these MWCNTs are compared. The flexural strength of the MWCNT/CF/VE composite with 1.0 phr acryl-MWCNTs content is 29.8% greater than that of neat CF/VE composites, and the flexural modulus of the MWCNT/CF/VE composite is 9.9% higher than that of neat CF/VE composites. Compared with neat CF/VE composites, 1.0 phr acryl-MWCNT/CF/VE composites exhibit an approximately 19.9 °C increase in glass transition temperature (Tg). The coefficients of thermal expansion significantly decreased from 47.2 ppm/°C of the neat CF/VE composites to 35.6 ppm/°C of the acryl-MWCNTs/CF/VE composites with 1 phr acryl-MWCNT content. This study provides a method for developing acryl-MWCNT/CF/VE composites with good dispersion of MWCNTs in VE matrix and strong interfacial interaction between the MWCNTs and VE matrix for enhancing the stress transfer from VE matrix to CF reinforcement.

Magnetic gold-nanorod/ PNIPAAmMA nanoparticles for dual magnetic resonance and photoacoustic imaging and targeted photothermal therapy.

Nanomedicine can provide a multi-functional platform for image-guided diagnosis and treatment of cancer. Although gold nanorods (GNRs) have been developed for photoacoustic (PA) imaging and near infra-red (NIR) photothermal applications, their efficiency has remained limited by low thermal stability. Here we present the synthesis, characterization, and functional evaluation of non-cytotoxic magnetic polymer-modified gold nanorods (MPGNRs), designed to act as dual magnetic resonance imaging (MRI) and PA imaging contrast agents. In addition, their high magnetization allowed MPGNRs to be actively localized and concentrated by targeting with an external magnet. Finally, MPGNRs significantly enhanced the NIR-laser-induced photothermal effect due to their increased thermal stability. MPGNRs thus provide a promising new theranostic platform for cancer diagnosis and treatment by combining dual MR/PA imaging with highly effective targeted photothermal therapy.

Effect of molecular chain length on the mechanical and thermal properties of amine-functionalized graphene oxide/polyimide composite films prepared by in situ polymerization.

This study fabricates amine (NH(2))-functionalized graphene oxide (GO)/polyimide(PI) composite films with high performance using in situ polymerization. Linear poly(oxyalkylene)amines with two different molecular weights 400 and 2000 (D400 and D2000) have been grafted onto the GO surfaces, forming two types of NH(2)-functionalized GO (D400-GO/D2000-GO). NH(2)-functionalized GO, especially D400-GO, demonstrated better reinforcing efficiency in mechanical and thermal properties. The observed property enhancement are due to large aspect ratio of GO sheets, the uniform dispersion of the GO within the PI matrix, and strong interfacial adhesion due to the chemical bonding between GO and the polymeric matrix. The Young's modulus of the composite films with 0.3 wt % D400-GO loading is 7.4 times greater than that of neat PI, and tensile strength is 240% higher than that of neat PI. Compared to neat PI, 0.3 wt % D400-GO/PI film exhibits approximately 23.96 °C increase in glass transition temperature (T(g)). The coefficient of thermal expansion below T(g) is significantly decreased from 102.6 µm/°C (neat PI) to 53.81 µm/°C (decreasing 48%) for the D400-GO/PI composites with low D400-GO content (0.1 wt %). This work not only provides a method to develop the GO-based polyimide composites with superior performances but also conceptually provides a chance to modulate the interfacial interaction between GO and the polymer through designing the chain length of grafting molecules on NH(2)-functionalized GO.

Improving thermal stability and efficacy of BCNU in treating glioma cells using PAA-functionalized graphene oxide.

BACKGROUND: 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a commercial chemotherapeutic drug for treating malignant brain tumors, has poor thermal stability and a short half-life. Immobilization of BCNU on a nanocarrier might increase the thermal stability of BCNU and extend its half-life. METHODS: Nanosized graphene oxide (GO) could be modified by polyacrylic acid (PAA) to improve the aqueous solubility and increase the cell penetration efficacy of the nanocarrier. PAA-GO intended as a drug carrier for BCNU was prepared and characterized in this study. The size and thickness of PAA-GO was investigated by transmission electron microscopy and atomic force microscopy, and the presence of PAA functional groups was confirmed by electron spectroscopy for chemical analysis and thermogravimetric analysis. BCNU was conjugated to PAA-GO by covalent binding for specific killing of cancer cells, which could also enhance the thermal stability of the drug. RESULTS: Single layer PAA-GO (about 1.9 nm) with a lateral width as small as 36 nm was successfully prepared. The optimum drug immobilization condition was by reacting 0.5 mg PAA-GO with 0.4 mg BCNU, and the drug-loading capacity and residual drug activity were 198 µg BCNU/mg PAA-GO and 70%, respectively. This nanocarrier significantly prolonged the half-life of bound BCNU from 19 to 43 hours compared with free drug and showed efficient intracellular uptake by GL261 cancer cells. The in vitro anticancer efficacy of PAA-GO-BCNU was demonstrated by a 30% increase in DNA interstrand cross-linking and a 77% decrease in the IC(50) value toward GL261 compared with the same dosage of free drug. CONCLUSION: Nanosized PAA-GO serves as an efficient BCNU nanocarrier by covalent binding. This nanocarrier will be a promising new vehicle for an advanced drug delivery system in cancer therapy.