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Lin X.,Nanjing Southeast University | Lin X.,State Key Laboratory of Bioelectronics | Li Y.,Tianjin Medical University | Gu N.,Nanjing Southeast University | Gu N.,State Key Laboratory of Bioelectronics
Soft Matter | Year: 2011

We have performed coarse grained molecular dynamics simulations (CGMD) to investigate the interactions of generation 7, 5 and 3 (G7, G5 and G3) charge-neutral polyamidoamine (PAMAM) dendrimers with a DPPC (dipalmitoylphosphatidylcholine) monolayer at the air-water interface (model pulmonary surfactant) during the end-expiration process. Our results show that different generations of PAMAM dendrimers have different influences on the DPPC monolayer. Generally, G3 PAMAM dendrimers show little influence on the DPPC monolayer's structure and relative properties. While G7 and G5 PAMAM dendrimers tend to induce the formation of largely deformed structures of the DPPC monolayer and inhibit or even reverse the normal phase transition of the interfacial DPPC molecules during the process of compression. Besides, we find that the formation processes of these disrupted structures are energy-favorable based on analyzing van der Waals interaction energy between PAMAM dendrimers and the whole system. © The Royal Society of Chemistry 2011.


Ma C.,State Key Laboratory of Bioelectronics | Ma C.,Guangdong University of Petrochemical Technology | Li C.,State Key Laboratory of Bioelectronics | Li C.,Nanjing Southeast University | And 12 more authors.
Journal of Biomedical Nanotechnology | Year: 2013

In many molecule biology and genetic technology studies, the amount of available DNA can be one of the important criteria for selecting the samples from different sources. Compared with those genomic DNA methods using organic solvents or other traditional commercial kits, the method based on magnetic nanoparticles (MNPs) and adsorption technology has many remarkable advantages like being time-saving and cost effective without the laborious centrifugation or precipitation steps, and more importantly it has the great potential and especially suitable for automated DNA extraction and up-scaling. In this paper, the extraction efficiency of genomic nucleic acids based on magnetic nanoparticles from four different sources including bacteria, yeast, human blood and virus samples are compared and verified. After measurement and verification of the extracted genomic nucleic acids, it was shown that all these genomic nucleic acids extracted using the MNPs method can be of high yield and be available for next molecule biological steps. Copyright © 2013 American Scientific Publishers All rights reserved.


Ma C.,State Key Laboratory of Bioelectronics | Ma C.,Guangdong University of Petrochemical Technology | Li C.,State Key Laboratory of Bioelectronics | Li C.,Nanjing Southeast University | And 18 more authors.
Journal of Biomedical Nanotechnology | Year: 2012

In this article, we present an easy route to prepare monodisperse core-shell Fe 3O 4@SiO 2 microspheres with uniform size and shape. Their structures and properties were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), and vibrating sample magnetometer (VSM), respectively. The results showed that spherical Fe 3O 4 microspheres with well dispersion have a rough surface and an average diameter (about 500 nm). After the modification with silica, the particles have a well-defined core-shell structure and a much smoother surface and larger particle diameter (about 600 nm). Furthermore, VSM measurements indicated that the as-prepared Fe 3O 4 and Fe 3O 4@SiO 2 microspheres were superparamagnetic at room temperature and the saturation magnetization (M s) were 58.110 emu/g and 33.479 emu/g, respectively. And then, the prepared monodisperse core-shell Fe 3O 4@SiO 2 microspheres were subsequently applied to separate nucleic acids from the bacteria (E. coli BL21) and verified the great application prospects for bioseparation technology of the biomoleculars. Copyright © 2012 American Scientific Publishers All rights reserved.


Wu Y.,State Key Laboratory of Bioelectronics | Zhou H.,Nanjing Southeast University | Wei W.,State Key Laboratory of Bioelectronics | Hua X.,State Key Laboratory of Bioelectronics | And 3 more authors.
Analytical Chemistry | Year: 2012

Apoptosis is involved in the pathology of a variety of diseases. The measurement of apoptosis will help us to evaluate the onset of disease and the effect of therapeutic interventions. In addition, the increased demand for understanding the early stages of apoptosis is pushing the envelope for solutions in early instance real-time monitoring of death kinetics. Here we present a novel electrochemiluminescent cytosensing strategy to quantitate apoptotic cell numbers, screen some anticancer drugs, and evaluate their effects on hepatocarcinoma cell line (HepG2) cells by utilizing the human antiphosphatidyl serine antibody (APSA) conjugated Ru(bpy) 3 2+-encapsulated silica nanoparticle (APSASiO 2@ Ru) as the detection probe. HepG2 cells were easily immobilized on the arginine-glycine- aspartic acid-serine (RGDS)- multiwalled carbon nanotubes (RGDS-MWCNTs) nanocomposite by the specific combination of RGD domains with integrin receptors on the cell surface. Then APSA-SiO 2@Ru was introduced to the surface of apoptosis cells through the specific interaction between APSA and phosphatidylserine (PS) that distributed on the outer membrane of apoptotic cells. On the basis of the signal amplification of the APSA-SiO2@Ru nanoprobe, the cytosensor could respond as low as 800 cells mL -1, showing very high sensitivity. In addition, the dynamic alterations of surface PS expression on HepG2 cells in response to drugs and the cell heterogeneity were also demonstrated. The strategy presented a promising platform for highly sensitive cytosensing and convenient screening of some clinically available anticancer drugs. © 2012 American Chemical Society.


Zhang T.,TU Munich | Zhang T.,State Key Laboratory of Bioelectronics | Troll C.,TU Munich | Rieger B.,TU Munich | And 3 more authors.
Journal of Catalysis | Year: 2010

An improved procedure, three-step reaction cycle procedure, for the continuous preparation of phosgene from CO, air and HCl catalyzed by CuCl2 was reported for the first time. The corresponding catalytic mechanism of each step was preliminarily disclosed with the powder X-ray diffraction (XRD) analysis: the first step is the oxychlorination of CO to phosgene and simultaneous reduction of CuCl2 to CuCl; the second step is the oxidation of CuCl with air to Cu2OCl2, and the third step is the neutralization of Cu2OCl2 with HCl to CuCl2. The regeneration of catalyst consists of steps 2 and 3, which is called the two-step regeneration of catalyst. The no-simultaneous existence of Cu (I) chloride and water in this three-step reaction procedure prevented effectively copper (I) chloride from the disproportionation. The influence of regeneration conditions, including reaction time, pressure of air or HCl on morphologies and recovery degree of catalyst were investigated and discussed. The degree of recovery for the single-run yield and cumulative yield of phosgene from the two-step regenerated oxychlorination agent can reach, respectively, 87.0% and 97.0% whereas the single-run yield and cumulative yield of phosgene with the one-step regenerated catalyst only can be recovered to 58.8% and 80.5%, respectively. The two-step regeneration method also can result in a higher dispersion of CuCl2/KCl on silica gel than that of the one-step regeneration. These results not only can offer a quite promising potential for the industrial use, but also can promote our deeply understanding of this important industrial reaction. © 2009 Elsevier Inc. All rights reserved.


Chen D.,State Key Laboratory of Bioelectronics | Wan S.,State Key Laboratory of Bioelectronics | Bao F.S.,University of Akron
IEEE Transactions on Neural Systems and Rehabilitation Engineering | Year: 2016

Over the past decade, with the development of machine learning, Discrete Wavelet Transform (DWT) has been widely used in computer-Aided epileptic EEG signal analysis as a powerful timefrequency tool. But some important problems have not yet been benefitted from DWT, including epileptic focus localization, a key task in epilepsy diagnosis and treatment. Additionally, the parameters and settings for DWT are chosen empirically or arbitrarily in previous work. In this work, we propose a framework to use DWT and Support Vector Machine (SVM) for epileptic focus localization problem based on EEG. To provide a guideline in selecting the best settings for DWT, we decompose the EEG segments in 7 commonly used wavelet families to their maximum theoretical levels. The wavelet and its level of decomposition providing the highest accuracy in each wavelet family are then used in a grid search for obtaining the optimal frequency bands and wavelet coefficient features. Our approach achieves promising performance on two widely-recognized intrancranial EEG datasets that are also seizurefree, with an accuracy of 83.07% on the Bern-Barcelona dataset and an accuracy of 88.00% on the UBonn dataset. Compared with existing DWT-based approaches in epileptic EEG analysis, the proposed approach leads to more accurate and robust results. A guideline for DWT parameter setting is provided at the end of the paper. © 2001-2011 IEEE.


Xiong F.,State Key Laboratory of Bioelectronics | Wang H.,China Pharmaceutical University | Feng Y.,China Pharmaceutical University | Li Y.,China Pharmaceutical University | And 6 more authors.
Scientific Reports | Year: 2015

Iron oxide nanoparticles (IONPs) are chemically inert materials and have been mainly used for imaging applications and drug deliveries. However, the possibility whether they can be used as therapeutic drugs themselves has not yet been explored. We reported here that Fe2O3 nanoparticles (NPs) can protect hearts from ischemic damage at the animal, tissue and cell level. The cardioprotective activity of Fe2O3 NPs requires the integrity of nanoparticles and is not dependent upon their surface charges and molecules that were integrated into nanoparticles. Also, Fe2O3 NPs showed no significant toxicity towards normal cardiomyocytes, indicative of their potential to treat cardiovascular diseases.


Ji X.,State Key Laboratory of Bioelectronics | Wang T.,State Key Laboratory of Bioelectronics | Guo L.,State Key Laboratory of Bioelectronics | Xiao J.,Nanjing Medical University | And 7 more authors.
Journal of Biomedical Nanotechnology | Year: 2013

Poly(L-lactide) acid (PLLA) was mixed with different content of nanoscale-ZnO (N-ZnO) and spun into nonwoven mats by electrospinning, the effects of the blending ratio of N-ZnO on mats morphology and mechanical properties were investigated. The prepared mats were characterized with infrared spectrometry (IR), Brunauer-Emmett-Teller (BET) surface area, the morphology and tensile test were investigated by scanning electron microscope (SEM) and electronic universal testing machine, respectively. The quantity of N-ZnO contained in mats was determinated by Na2 EDTA titration method, then the N-ZnO loading coefficient (%, NL) could be figured out. Infrared spectrometry showed that the electrospun PLLA/N-ZnO mats were prepared successfully. When the concentration of N-ZnO contained in the mats increased from 0 to 2% (w/v), the curves of stress-strain indicated that the elastic modulus of mats ranged among 5.16 to 15.59 MPa. In addition, the electrospun PLLA/N-ZnO exhibited lower cell proliferation for UE7T-13 cells than electrospun PLLA mats and control. The results presented that the N-ZnO added in the mats enhanced the toughness of PLLA/ZnO mats to some extent, though the biocompatibility of blends was not good. Copyright © 2013 American Scientific Publishers All rights reserved.


Ji X.,State Key Laboratory of Bioelectronics | Yang W.,Jiangsu University | Wang T.,State Key Laboratory of Bioelectronics | Mao C.,Nanjing Normal University | And 4 more authors.
Journal of Biomedical Nanotechnology | Year: 2013

Biodegradable core/shell structured poly(L-lactide) acid (PLLA)/chitosan (CS) nanofibers were fabricated by coaxial electrospinning. PLLA and CS were dissolved in dichloromethane and aqueous acetic acid solvents for spinning into core and shell layers, respectively. CS of high molecular weight was difficult to spin into nanofibers by electrospinning due to its high viscosity, but it was easier to achieve by coaxial electrospinning with PLLA. The preparation conditions were optimized by changing the ratios of PLLA/CS under different jet voltages. After being investigated by scanning electron microscope (SEM), a smooth structure was prepared using 2% CS as the shell solution with applied voltage 15 kV. Transmission electron microscopy (TEM) study and infrared spectrometry (IR) characterization of PLLA/CS nanofibers indicated that the core/shell structure was successfully fabricated. Brunauer-Emmett-Teller (BET) surface area and pore size distribution exhibited higher capacity of PLLA/CS than PLLA used as drug carrier in tissue engineering. The cytocompatibility of nanofibers were evaluated by co-cultured with human bone marrow-derived UE7T-13 cells, the 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) test exhibited good proliferation of PLLA/CS for cells. Results of blood compatibility tests showed decreased hemolytic ratio and platelets adhesion of PLLA/CS compared with PLLA. The results indicated that PLLA/CS nanofibers could be potential drug carrier for tissue engineering. Copyright © 2013 American Scientific Publishers All rights reserved.


Huang R.,State Key Laboratory of Bioelectronics | Xi Z.,State Key Laboratory of Bioelectronics | He N.,State Key Laboratory of Bioelectronics
Science China Chemistry | Year: 2015

Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have been applied. Aptamers can bind to a wide range of targets that include small organic molecules, inorganic compounds, haptens and even whole cells with high binding affinity and specificity. Aptamers for wide range of targets have been selected currently. In addition, aptamers are thermo stable and can also be regenerated easily within a few minutes denaturation, which makes them easy to store or handle. These advantages make aptamers extremely suitable for applications based on molecular recognition as analytical, diagnostic and therapeutic tools. In this review, the recent applications of aptamers for chemistry analysis, medicine and food security, along with the future trend will be discussed. © 2015 Science China Press and Springer-Verlag Berlin Heidelberg

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