Latest ArticlesNanomaterials as drug carriers hold promise for the treatment of carcinomas, but integrating multiple functions into a single vector is difficult. In this study, we aim to develop efficient materials as vectors for co-delivery of microRNA-122 (miR-122) and sorafenib (SRF). We successfully synthesized amphiphilic galactose-modified PEGylated poly(amino-co-ester) (Gal-PEG-PPMS) copolymers consisted of hydrophilic Gal-PEG5k chain segments and hydrophobic poly(ω-pentadecalactone-co-N-methyldiethyleneamine-co-sebacic acid) chain segments, which self-assembled to form cationic micelles at pH 5.2. The results showed that the micelles could encapsulate SRF and bind miR122 simultaneously, increase cellular uptake efficiency. Furthermore, the micelles showed favorable transfection efficiency in enhancing miR122 expression level, the migration and invasion ability of hepatocellular carcinoma (HCC) cells were significantly inhibited after being transfected with miR122-loaded micelles. Most importantly, the co-delivery micelles decreased cell activities of HepG2 cells, which was more effective than miR122 or SRF loaded micelles alone. Collectively, Gal-PEG-PPMS nanoparticles are promising multifunctional carriers for miR122 and SRF co-delivery system to treat HCC.
A friendly biomimetic process was adopted for the mild preparation of "all-inclusive" organic-inorganic nanospheres, which effectively integrate biorecognition function and signal amplification function. The resulted Ca3(PO4)2-Ab2-BSA nanospheres were employed as signal labels for enhancing detection of nuclear matrix protein 22 (NMP 22). The fabricated electrochemical immunosensor exhibited a linear range (0.08-77.00 U/mL) and an ultralow limit of detection (0.01 U/mL) towards NMP 22, which can be taken as a promising tool for clinical diagnosis of bladder cancer.
Here, we use two important biomaterials, protein and DNA, to construct self-assembled linear nanostructures through Watson-Crick base-paring of DNAs. We apply a simple magnetic separation method to purify traptavidin-DNA conjugates, and demonstrate synthesis of linear arrays of traptavidinDNA conjugates via the step-growth polymerization approach with pre-determined DNA sequences. Using the traptavidin-DNA array as a template, we assemble gold nanoparticles to form linear plasmonic nanostructures in a programmable manner. The traptavidin-DNA conjugates thus provide a convenient platform for one-dimensional assembly of biotinylated nanomaterials for many biomedical applications from drug delivery to bio-sensing.
Cancer therapy with nanoscale drug formulations has made significant progress in the past few decades. However, the selective accumulation and release of therapeutic agents in the lesion sites are still great challenges. To this end, we developed a cRGD-decorated pH-responsive polyion complex (PIC) micelle for intracellular targeted delivery of doxorubicin (DOX) to upregulate tumor inhibition and reduce toxicity. The PIC micelle was self-assembled via the electrostatic interaction between the positively charged cRGD-modified poly(ethylene glycol)-block-poly(L-lysine) and the anionic acid-sensitive 2, 3-dimethylmaleic anhydride-modified doxorubicin (DAD). The decoration of cRGD enhanced the cell internalization of PIC micelle through the specific recognition of αvβ3 integrin on the membrane of tumor cells. The active DOX was released under intracellular acidic microenvironment after endocytosis following the decomposition of DAD. Moreover, the targeted PIC micelle exhibited enhanced inhibition efficacies toward hepatoma in vitro and in vivo compared with the insensitive controls. The smart multifunctional micelle provides a promising platform for target intracellular delivery of therapeutic agent in cancer therapy.
Stimuli-responsive polypeptides have been intensively investigated for controlled drug release, owing to their favorable biocompatibility and biodegradability. In this work, we designed and synthesized a new kind of polypeptide bearing 1, 4-dithiane pendants for reactive oxygen species (ROS)-responsive drug release. The polypeptide-based block copolymer was facilely synthesized by ring-opening polymerization (ROP) of 1, 4-dithian-substituted L-glutamate N-carboxyanhydride (DTG-NCA) monomer using an amino-terminated poly(ethylene glycol) methyl ether (mPEG-NH2) as the macromolecular initiator. The resultant block copolymer, mPEG-b-PDTG, could self-assemble into uniform micelles in aqueous medium owing to its amphiphilic structure. Then, the H2O2-triggered oxidation behaviors of the mPEG-b-PDTG micelles were studied by dynamic light scattering (DLS), FT-IR and turbidimetric assay. It was revealed that the oxidation of thioether into sulfoxide in the side chains would result in disassembly of the micelles. Furthermore, the ROS-responsive drug release behavior of the mPEG-b-PDTG micelles was verified by using Nile Red as a model drug. MTT assay also proved that mPEG-b-PDTG was non-toxic in B16F10 and L929 cells. Therefore, such a new class of oxidation-responsive polypeptide might provide a promising platform for ROS-responsive drug delivery.
Achieving stable deep blue organic light emitting diodes (OLEDs) with narrow full width at half maximum (FWHM) and color gamut in the range of the commission International de L'Eclairage (CIE) of y ≤ 0.10 is still challenging in display and lighting applications. In this investigation, three donor-acceptor (D-A) deep-blue emitters were designed and synthesized via integrating asymmetric quinazoline (PQ) acceptor with weak donating carbazole (Cz) donor. The effect of the position and number of Cz group in PQ unit are investigated, which is also first examples for systematic research about the effect of different position of asymmetric PQ as acceptor on deep OLEDs. Their bandgaps of 3.12~3.19 eV and the singlet state energy levels of 3.12~3.19 eV were found to be sufficiently large to achieve deep blue light. As expected, these emitters-based OLEDs exhibit deep blue emission with the maximum wavelength ≤ 450 nm and narrow FWHM ≈ 60 nm. Especially, a CIE of y=0.080 was achieved for 4PQ-Cz-based OLED. Significantly, the deep blue electroluminescence (EL) spectra of these three emitters-based OLEDs are very stable and the corresponding CIE coordinates deviation △CIE (x, y)) can be negligible under the applied voltage ranging from 5 V to 9 V.
A new simple bifunctional chemosensor 1 based on rhodamine was synthesized by hydrazide and formylformic acid, which could detect Cu2+ and Hg2+ via different detecting methods in CH3CN-HEPES buffer solution (20 mmol/L, pH 7.4) (1:9, v/v) respectively. When sensor 1 bound with Cu2+, it showed a colorimetric change, while a selective enhancement in fluorescence occurred upon 1 binding with Hg2+, resulting from the spirolatam-ring opening process. The binding modes of 1 with Cu2+ and Hg2+ were investigated based on UV, fluorescence change, ESI-Mass and Job's Plot data. Moreover, sensor 1 could selectively detect target ion in a mixed solution of Cu2+ and Hg2+, and the two metal ions do not interfere with each other in the process of detecting Cu2+ or Hg2+ with 1.
Due to the serious harm of diabetes to human health, development of sensitive assays for glucose level is of high significance for early prevention and treatment of diabetes. Currently, most conventional enzyme-based glucose sensors suffer from high cost and low stability due to the inherent defects of natural enzymes. Herein, we develop a pure nanozyme-based glucose detection method using Ag@Au core/shell triangular nanoplates (TNPs), which combines glucose oxidase (GOD)-and horseradish peroxidase (HRP)-like activities of the Au shell and inherent plasmonic properties of Ag TNPs. The sensing mechanism is based on the fact that the Au shell possessed GOD-like activity, enabling the oxidation of glucose to produce H2O2, which can further etch the silver core, leading to the decrease of absorbance at 800 nm and the color change from blue to colorless. Compared with the previous nanozymes-based glucose sensors, our method avoids the use of enzymes and organic chromogenic agent. Moreover, the stability of the Ag@Au core/shell TNPs is much better than that of Ag TNPs due to the protection by the coating of the Au shell. This method was successfully applied to the detection of urine samples from patients with diabetes, indicating its practical applicability for real sample analysis.
MXene-based electrode materials exhibit favorable supercapacitor performance in sulfuric acid due to praised pseudocapacitance charge storage mechanism. However, self-stacking of conventional MXene electrodes severely restricts their electrochemical performance, especially at high loading. Herein, a flexible cross-linked porous Ti3C2Tx-MXene-reduced graphene oxide (Ti3C2Tx-RGO) film is skillfully designed and synthesized by microscopic explosion of graphene oxide (GO) at sudden high temperature. The generated chamber structure between layers could hold a few of electrolyte, leading to a close-fitting reaction at interlayer and avoiding complex ions transmission paths. The Ti3C2Tx-RGO film displayed a preferable rate performance than that of pure Ti3C2Tx film and a high capacitance of 505 F/g at 2 mV/s. Furthermore, the uniform intralayer structure and unique energy storage process lead to thickness-independenct electrochemical performances. This work provides a simple and feasible improvement approach for the design of MXene-based electrodes, which can be spread other electrochemical systems limited by ions transport, such as metal ions batteries and catalysis.
Ti3C2Tx has shown great potential in energy storage filed, but the restacking between Ti3C2Tx nanosheets seriously hampers the maximization of its capacitance. In this study, we rationally designed and synthesized porous Ti3C2Tx assemblies without any additive by introducing ice as spacers using a facile freeze-drying method. The porous Ti3C2Tx assemblies have a three-dimensional network structure, which consists of ultra large Ti3C2Tx lamellar walls and lots of macro- and mesopores. It has been proven that there are more-O groups on the surface of the porous Ti3C2Tx assemblies than the Ti3C2Tx film. The porous Ti3C2Tx assemblies deliver a maximum areal capacitance of 1668 mF/cm2 when the mass loading is 8.4 mg/cm2, an optimized specific capacitance of 247.2 F/g when the mass loading is 5.3 mg/cm2, and 87% capacitance retention over 10000 cycles. The symmetric solid-state supercapacitors based on the porous Ti3C2Tx assemblies show an areal capacitance of 355.8 mF/cm2, the maximum power density of 50 mW/cm2 and an outstanding flexibility under different deformation.