Latest ArticlesAn improved ssDNA library immobilized systematic evolution of ligands by enrichment (SELEX) was applied to select aptamers against carbaryl. After nine selection rounds, a highly enriched ssDNA pool was obtained. The Apta3 was demonstrated as the optimal aptamer. In order to facilitate the modification of aptamer, the Apta3 was further truncated with the dissociation constant (Kd) of 0.364±0.055 μmol/L and a fluorescent aptasensor was developed. The linear range for carbaryl was from 100 nmol/L to 1500 nmol/L, with the limit of detection was as low as 15.23 nmol/L. Besides, the biosensor was validated for the carbaryl spiked real samples, and the recoveries were between 97.7% and 107.3%.
Vaccine adjuvants have been widely used to enhance the immunogenicity of the antigens and elicit long-lasting immune response. However, only few vaccine adjuvants have been approved by the FDA for human use so far. Therefore, there is still an urgent need to develop novel adjuvants for the potential applications in clinical trials. Herein, non-nucleotide small molecule STING agonist diABZI was employed to construct glycopeptide antigen based vaccines for the first time. Immunological evaluation indicated diABZI not only enhanced the production of antibodies and T cell immune responses, but also inhibited tumor growth in tumor-bearing mice in glycopeptide-based subunit vaccines. These results indicated that di-ABZI demonstrates a high potential as adjuvant for the development of cancer vaccines.
We have developed a MUC1 antigen-based antitumor vaccine loaded on alum colloid encapsulated inside β-glucan particles (GP-Al). The constructed vaccine induced strong MUC1 antigen specific IgG antibody titers and enhanced CD8+ T cells cytotoxic effect to kill tumor cells. These results indicated that GP-Al can be served as an efficient delivery system and adjuvant for the development of cancer vaccines especially small molecule antigens based cancer vaccines.
Energy transfer and electron transfer are both fundamental mechanisms enabling numerous functional materials and applications. While most materials systems employ either energy transfer or electron transfer, the combined effect of energy and electron transfer processes in a single donor/acceptor system remains largely unexplored. Herein, we demonstrated the energy transfer followed by electron transfer (ETET) process in a molecular dyad TPE-NBD. Due to energy transfer, the fluorescence of TPE-NBD was greatly enhanced in non-polar solvents. In contrast, polar solvents activated subsequent electron transfer and markedly quenched the emission of TPE-NBD. Consequently, ETET endows TPE-NBD with significant polarity sensitivities. We expect that employing ETET could generate many functional materials with unprecedented properties, i.e., for single laser powered multicolor fluorescence imaging and sensing.
The reaction of a metallo-organic ligand (LA) in which two "V"-shaped bisterpyridines attaching to meta-position of "X"-shaped tetraterpyridine via < tpy-Ru2+-tpy > connectivity and Zn2+ ions gave rise to 3D supramolecular architectures: octagram (Zn8LA4). However, a position varied ligand (LB) in which two "V"-shaped bisterpyridines locating at the ortho-position of "X"-shaped tetraterpyridine afforded a different 3D hexagram (Zn6LB3). Full characterizations included NMR (1H, 13C, 2D COSY, NOESY and DOSY), ESI-MS, TWIM-MS, TEM and AFM. The resulted structures were directly determined by the position of two "V"-shaped bisterpyridines attaching to "X"-shaped tetraterpyridine.
Methane (CH4) controllable activation is the key process for CH4 upgrading, which is sensitive to the surface oxygen species. The high thermal conductivity and superb thermal stability of the hexagonal boron nitride (h-BN) sheet makes a single transition metal atom doped hexagonal boron nitride monolayer (TM-BN) possible to be a promising material for catalyzing methane partial oxidation. The performances of 24 TM-BNs for CH4 activation are systematically investigated during the CH4 oxidation by means of first-principles computation. The calculation results unravel the periodic variation trends for the stability of TM-BN, the adsorption strength and the kind of O2 species, and the resulting CH4 activation performance on TM-BNs. The formed peroxide O22- of which the O—O bond could be broken and O- anions are found to be reactive oxygen species for CH4 activation under the mild conditions. It is found that the redox potential of TM center, including its valence electron number, coordination environment, and the work function of TM-BN, is the underlying reason for the formation of different oxygen species and the resulting activity for CH4 oxidative dehydrogenation.
Two-dimensional covalent organic framework (COF) has distinctive properties that offer potential opportunities for developing advanced electrode materials. In this work, a core-shell material composed of TAPB-DMTP-COF (TAPB, 1, 3, 5-tris(4-aminophenyl)benzene; DMTP, 2, 5-dimethoxyterephaldehyde) core and conducting polymer shell, TAPB-DMTP-COF@PANI, was synthesized solvothermally using a polymerization method. The structural characteristics of the prepared composite were revealed by X-ray diffraction patterns (XRD), fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM). The electrochemical analyses were verified by subsequent monitoring of trace levels of acetaminophen. This resultant composite not only facilitated acetaminophen to interact with absorption sites by π-π stacking effect and hydrogen bonding but also overcame the poor conductivity of COF. Under the optimal conditions, a low limit of detection of 0.032 μmol/L and wide linear range of 0.10-500 μmol/L were obtained. The electrochemical platform was almost unaffected by other interfering substances, and successfully applied for the practical detection of acetaminophen in commercial tablet, human blood serum and urine. The enhanced performance makes this COF based core-shell composite a promising material in electrochemical sensor.
This work reports the investigation of a new triptycene-derived oxacalixarene (TDOC) as the stationary phase for gas chromatography (GC) with high-resolution performance for a wide range of analytes and isomers. The TDOC scaffold is composed of triptycene and 1, 8-naphthyridine moieties, inherently differing from the conventional calixarenes in structures and properties. As a result, the TDOC column exhibited outstanding column efficiency of 5679 plates/m by n-dodecane at 120 ℃. It showed advantageous performance for separations of the mixtures with various analytes and achieved high resolution of diverse isomers (skeletal, positional and cis-/trans-isomers) from apolar to polar nature. Moreover, the TDOC column exhibited high thermal stability up to 310 ℃. To date, the TDOC-based materials have not been reported in chromatography. This work demonstrates the good potential of the triptycene-derived heterocalixarenes as a new class of stationary phases for chromatographic analyses.
Cyclin-dependent kinases 4 and 6 inhibitors (CDK4/6i) have been demonstrated to trigger antitumor immunity for tumor regression. However, the therapeutic performance of CDK4/6i-meadiated cancer immunotherapy was impaired by the immunosuppressive tumor microenvironment (ITM) due to overexpression of programmed death ligand 1 (PD-L1) on the surface of cancer cell membrane. To improve the immunotherapeutic performance of CDK4/6i, we herein developed endosomal acid-activatable micelleplex for siRNA delivery and PD-L1 knockdown in the tumor cells in vitro and in vivo. We further demonstrated that the combination of PD-L1 knockdown and CDK4/6 inhibition facilitated intratumoral infiltration of cytotoxic T lymphocytes (CTLs), and elicited protective immune response and efficiently suppressed tumor growth in vivo. This study revealed the importance of molecular design of the micelleplex for highly efficient siRNA delivery, which might provide a novel insight for RNAi-based cancer immunotherapy.
The sensitive and rapid detection of blood glucose is very important for monitoring and managing diabetes. Herein, a fluorescent/magnetic bimodal sensing strategy is proposed for glucose detection using a multifunction-responsive nanocomposite (MoS2 QDs-MnO2 NS). MoS2 QDs act as fluorescent probes, and MnO2 nanosheets are used as both quenchers and recognizers in this sensing platform. In the presence of glucose-mediated enzyme product (H2O2), MnO2 nanosheet is etched, thus releasing MoS2 QDs and Mn2+ ions, which causes the significantly enhancement of fluorescent and magnetic signals. Furthermore, MoS2 QDs-MnO2 NS-based fluorescent test paper is constructed for H2O2 sensing with the naked eyes. Under optimal conditions, the dual linear ranges of 20-300 μmol/L and 40-250 μmol/L toward glucose detection are obtained for the fluorescent and magnetic mode, respectively. Furthermore, this bimodal assay exhibits good reproducibility and acceptable accuracy in glucose detection of clinical samples, demonstrating great versatility and flexibility of multifunctional probes in glucose detection.