Institute of Chemistry
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A hybrid linkage mode between T2,2 and T3 selenide clusters
No full textA multi-level 3D selenide framework in an In3+-Ge4+ system was synthesized. The interconnection between super-supertetrahedral T2,2 and supertetrahedral T3 clusters via their terminal Se2- leads to a previously unknown hybrid T2,2-T3 linkage mode. The synthetic realization of this material represents another new level of complexity and demonstrates the versatility in the construction and property-engineering of cluster-based semiconducting materials
Acid-labile boronate-bridged dextran-bortezomib conjugate with up-regulated hypoxic tumor suppression
No full textAn acid-labile dextran-bortezomib conjugate (Dex-BTZ), i.e., a macro-molecularized proteasome inhibitor, is synthesized by a boron esterification reaction. The prodrug exhibits intracellular acidity-accelerated BTZ release, and up-regulated inhibition efficacies toward hypoxic tumor in vitro and in vivo through both NF-kappa B- and ERS-mediated apoptosis signaling pathways
Biomimetic nanoassembly for targeted antigen delivery and enhanced Th1-type immune response
No full textA new type of biomimetic nanoassembly for targeted antigen delivery and enhanced Th1-type response is reported for the first time, to combat the major challenges in the treatment of infected cells
Constructing supramolecullar grids: from 4f square to 3d-4f grid
No full textThe first supramolecular 3d-4f grid was constructed using novel dihydrazone based ligands
Fabrication of Multifunctional SiO2@GN-Serum Composites for Chemo-Photothermal Synergistic Therapy
No full textRecently, the chemo-photothermal synergistic therapy has become a potential method for cancer treatment. Herein, we developed a multifunctional nanomaterial for chemo-photothermal therapeutics based on silica and graphene core/shell structure (SiO2@GN) because of the ability of GN to convert light energy into heat. Serum protein was further modified onto the surface of GN (SiO2@GN-Serum) to improve the solubility and stability of GN-based nanoparticles in physiological conditions. The as-synthesized SiO2@GN-Serum nanoparticles (NPs) have been revealed to have high photothermal conversion efficiency and stability, as well as high storage and release capacity for anticancer drug doxorubicin (SiO2@GN-Serum-Dox). The therapeutic efficacy of SiO2@GN-Serum-Dox has been evaluated in vitro and in vivo for cervical cancer therapy. In vitro cytotoxicity tests demonstrate that SiO2@GN-Serum NPs have excellent biocompatibility. However, SiO2@GN-Serum-Dox NPs show higher cytotoxicity than SiO2@GN-Serum and free Dox under irradiation with NIR laser at 1.0 W/cm(2) for 5 min owing to both SiO2@GN-Serum-mediated photothermal ablation and cytotoxicity of light-triggered Dox release. In mouse models, the tumor growth is significantly inhibited by chem-photothermal effect of SiO2@GN-Serum-Dox. Overall, compared with single chemotherapy or photothermal therapy, the combined treatment demonstrates better therapeutic efficacy. Our results suggest a promising GN-based core/shell nanostructure for biomedical applications
pH-Responsive Poly(ethylene glycol)/Poly(L-lactide) Supramolecular Micelles Based on Host-Guest Interaction
No full textpH-responsive supramolecular amphiphilic micelles based on benzimidazole-terminated poly(ethylene glycol) (PEG-BM) and beta-cyclodextrin-modified poly(l-lactide) (CD-PLLA) were developed by exploiting the hostguest interaction between benzimidazole (BM) and beta-cyclodextrin (beta-CD). The dissociation of the supramolecular micelles was triggered in acidic environments. An antineoplastic drug, doxorubicin (DOX), was loaded into the supramolecular micelles as a model drug. The release of DOX from the supramolecular micelles was clearly accelerated as the pH was reduced from 7.4 to 5.5. The DOX-loaded PEG-BM/CD-PLLA supramolecular micelles displayed an enhanced intracellular drug-release rate in HepG2 cells compared to the pH-insensitive DOX-loaded PEG-b-PLLA counterpart. After intravenous injection into nude mice bearing HepG2 xenografts by the tail vein, the DOX-loaded supramolecular micelles exhibited significantly higher tumor inhibition efficacy and reduced systemic toxicity compared to free DOX. Furthermore, the DOX-loaded supramolecular micelles showed a blood clearance rate markedly lower than that of free DOX and comparable to that of the DOX-loaded PEG-b-PLLA micelles after intravenous injection into rats. Therefore, the pH-responsive PEG-BM/CD-PLLA supramolecular micelles hold potential as a smart nanocarrier for anticancer drug delivery
基于玻璃固态纳米孔的生物传感应用研究
No full text纳米孔分析技术是一类年轻又具有广阔发展前景的学科，它提供了用于单分子检测、生物识别、单分子物理化学研究的独特的平台，具有免标记、成本低、高灵敏、特异性及快速便捷等特点，引起了众多学者广泛的研究兴趣。本论文选择单个玻璃毛细管纳米孔作为传感平台，研究其在生物检测中的应用。具体工作如下： (1) 我们使用单个锥形玻璃毛细管纳米孔作为传感平台，首次系统地研究了小的单层磷脂囊泡穿过固态纳米孔的穿孔行为动力学。在施加恒电压的条件下，我们可以清楚地观察到一个接一个独立的囊泡穿过纳米孔所产生的离子电流脉冲信号。单层磷脂囊泡的穿孔行为引起离子阻塞电流脉冲信号在幅度大小和穿孔迟滞时间上的变化，以上信号可以通过改变实验条件（包括纳米孔孔径，溶液pH，囊泡浓度，施加的电压以及纳米孔内表面电荷性质等）进行调控。另外，研究结果表明磷脂囊泡穿过纳米孔的驱动力主要是电泳力，这个结论在研究不同实验条件时可以证明。值得一提的是，在不同实验条件下，磷脂囊泡和纳米孔之间可能有不同的相互作用力，这使得该传感平台可应用于区分不同的磷脂囊泡。 (2) 我们使用激光玻璃毛细管拉制仪可以直接制备孔径～30 nm的玻璃纳米孔，并用电化学方法对其孔径进行估算。首次将聚谷氨酸（PGA）与铜离子的相互作用应用于基于单个玻璃纳米孔传感器平台的铜离子检测，可以快速、灵敏地实现金属铜离子的检测。该检测方法简单，且具有较好的铜离子选择性及重复性。通过调节纳米孔内外电解质溶液浓度，能够显著地提高检测灵敏度。该将传感器平台浸泡在pH较低的溶液中能够实现再生。此外，这种方法成功地应用于微体积的实际样品（工厂废水、葡萄酒等）中铜离子的检测，检测体积可低至20 μL。Solid state glass-based nanopores have attracted many researchers’ interest since the nanopore analysis provides a unique platform for single molecule detection, biochemical identification as well as single molecular physical chemistry research. Also, it has many outstanding characteristics, such as label free, low cost, high sensitivity, specificity as well as fast and convenient. In this thesis, we mainly focused on the surface modification/functionalization, as well as their applications in bioassays by using the single glass nanopores as sensing platforms. The main points of this thesis are outlined as follows: (1) Artificial single conical glass capillary-based nanopores were used as a model platform to systematically investigate the translocation behaviors and dynamics of small unilamellar vesicles (SUVs) through small artificial nanopores. Dynamic translocation of individual SUVs one by one through the nanopores were clearly observed and counted by the occurrence of periodic oscillation in ionic current blockage signal under an applied negative bias voltage. Translocation behaviors of the SUVs, in terms of magnitude and duration of ionic current blockage signal, vary and can be modulated by varying stimulus parameters (such as nanopore size, solution pH, vesicle concentration, applied voltage, and inner surface charge properties of glass nanopores). The translocation of the SUVs through glass nanopores turned out to be mainly driven by electrophoretic force in our case, which had been verified briefly under different stimulus parameters. It was worth mentioning that this sensing platform may open possibilities to distinguish different types of SUVs which may have different interactions with the nanopore under appropriate experimental conditions. It can be realized by modulating different stimulus parameters. (2) The glass capillary nanopores were produced by laser-assisted pipet puller with inner diameters of about 30 nm, whose inner diameter could be estimated by using electrochemical measurement. The glass capillary nanopore-based sensing platform was used for fast and selective detection of cupric ions by utilizing polyglutamic acid (PGA) as probes for the first time. This simple and effective nanopore sensor can be fabricated easily without any further complicated processes of functionalization. In addition, the sensitivity of the PGA-nanopore sensor can be improved about 1－2 orders of magnitude by simply employing asymmetric salt gradients during the detection. It could be renew by immersing into solution with low pH to release the cupric ions and refresh the sensing surface/interface. This sensing method had also showed its practicality in detecting industry wastewater and grape wine real samples with small volume down to 20 μL
Electron-Acceptor-Dependent Light Absorption and Charge-Transfer Dynamics in N-Annulated Perylene Dye-Sensitized Solar Cells
No full textIn this article, we report two metal-free perylene dyes (C269 and C270) featuring the electron acceptors benzothiadiazolebenzoic acid and ethynylbenzothiadiazolebenzoic acid, respectively, in combination with a bis(4-(hexyl)phenyl)amino-capped N-annulated perylene (NP) electron donor. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations revealed that the use of ethynylbenzothiadiazolebenzoic acid can lower the level of the lowest unoccupied molecular orbital (LUMO), reduce the energy gap, and attenuate the Stokes shift of an NP dye. These effects are in good accord with electrochemical and photophysical measurements. When used in sensitized titania solar cells, C270 dye exhibits a reasonably good power conversion efficiency close to 9% at an irradiance of 100 mW cm2 simulated AM1.5 sunlight. It was also found that, with respect to C269, C270 dye forms a thinner and looser self-assembled dye layer on the surface of titania, accounting for the shorter electron lifetime and lower open-circuit photovoltage for cells made with C270. Our femtosecond transient absorption (fs-TA) measurements confirmed a positive relationship between the driving energy and electron-injection rate despite the close-to-unity electron-injection yields for both dyes. In addition, the target analysis of fs-TA data indicated that, with respect to C269, more electrons are injected from the relaxed excited states for C270 dye with a lower LUMO level
Effect of grafted PEG chain conformation on albumin and lysozyme adsorption: A combined study using QCM-D and DPI
No full textIn this study, elucidation of protein adsorption mechanism is performed using dual polarization interferometry (DPI) and quartz crystal microbalance with dissipation (QCM-D) to study adsorption behaviors of bovine serum albumin (BSA) and lysozyme (LYZ) on poly (ethylene glycol) (PEG) layers. From the analysis of DPI, PEG2000 and PEG5000 show tight and loose mushroom conformations, respectively. Small amount of LYZ could displace the interfacial water surrounding the tight mushroomed PEG2000 chains by hydrogen bond attraction, leading to protein adsorption. The loose mushroomed PEG5000 chains exhibit a more flexible conformation and high elastic repulsion energy that could prevent protein adsorption of all BSA and most of LYZ. From the analysis of QCM, PEG2000 and PEG5000 show tight and extended brush conformations. The LYZ adsorbed mass has critical regions of PEG2000 (0.19 chain/nm(2)) and PEG5000 (0.16 chain/nm(2)) graft density. When graft density of PEG is higher than the critical region (brush conformations), the attraction of hydrogen bonds between PEG and LYZ is the dominant factor. When graft density of PEG is lower than the critical region (mushroom conformations), elastic repulsion between PEG and proteins is driven by the high conformation entropy of PEG chains, which is the dominant force of steric repulsion in PEG-protein systems. Therefore, the adsorption of BSA is suppressed by the high elastic repulsion energy of PEG chains, whereas the adsorption of LYZ is balanced by the interactions between the repulsion of entropy elasticity and the attraction of hydrogen bonds. (C) 2015 Elsevier B.V. All rights reserved
