Shanghai Tofflon Science and Technology Co.

Shanghai, China

Shanghai Tofflon Science and Technology Co.

Shanghai, China
Time filter
Source Type

Sun X.,University of Shanghai for Science and Technology | Li D.,University of Shanghai for Science and Technology | Guo B.,Shanghai Tofflon Science and Technology Co.
Shanghai Ligong Daxue Xuebao/Journal of University of Shanghai for Science and Technology | Year: 2016

The approaches of microcalorimetry and molecular dynamic simulation were adopted to investigate the protective effect caused by adding protectants. The results indicate that disaccharide protectants are able to maintain the molecular structure of insulin and contribute to the thermal stability of insulin due to the regional selective adsorption of protectants on the surface of insulin. Among four disaccharide protectants, the protectant with stronger adsorption ability conducts better performance in stabilizing the molecular structure of protein. With increasing the concentration of protectants, the thermal stability of insulin changes from increasing to gradually stable state. A further analysis upon the interaction between protectants and water reflects that increasing the thermal stability of insulin is attributed mainly to the interaction between insulin and disaccharides. © 2016, Editorial Board of Journal of USST. All right reserved.

Li D.-X.,University of Shanghai for Science and Technology | Guo B.-S.,Shanghai Tofflon Science and Technology Co. | Tao L.-G.,Lionco Pharmaceutical Co. | Liu L.,University of Shanghai for Science and Technology | And 2 more authors.
Chinese Pharmaceutical Journal | Year: 2016

OBJECTIVE: To research and regulate the crystal quality of alanylglutamine for improving their stability and pharmacodynamics as well as vacuum freeze-drying efficiency. METHODS: Scanning electron microscopy (SEM), X-ray powder diffractometer (XRD), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TG) as well as lyophilized experiments were used to investigate the effect of pre-freeze method on crystallinity and uniformity of particle size of alanylglutamine. RESULTS: The result of SEM revealed that the lyophilized alanylglutamine with accelerated pre-freeze method is small-size particle with low crystallinity. Then the lyophilized alanylglutamine with multi-step annealing pre-freeze method become uniformly large particle with high crystallinity. The RESULTS of XRD and DSC indicted that, comparing with the lyophilized alanylglutamine with accelerated pre-freeze method, the lyophilized sample with multi-step annealing pre-freeze method is easier to form the crystal medicine with uniform particle size, less crystal defects, high crystallinity. And the former has lower stability than the later. CONCLUSION: The final lyophilized experiment give us a CONCLUSION that using the multi-step annealing pre-freeze method can improve the freeze-drying efficiency and crystal quality of alanylglutamine, which to achieve the ultimate goal of cost and energy saving. Copyright 2016 by the Chinese Pharmaceutical Association.

Zheng J.,Shanghai Tofflon Science and Technology Co.
Canadian Journal of Chemical Engineering | Year: 2016

Polyacrylonitrile ultrafiltration membranes have been widely used in many separation processes. In this paper, horseradish peroxidase was immobilized onto polyacrylonitrile ultrafiltration membrane by crosslinking with glutaraldehyde. The immobilized enzyme possessed a protein loading of 0.025mg/cm2 membrane and a specific activity of 105U/mgprotein (105μmol/min/mgprotein). The initial modified and immobilized membranes were observed using SEM and FTIR. Potential applications of HRP membranes were investigated in the removal of phenol through oxidation with the addition of hydrogen peroxide. The optimum pH of the immobilized enzyme was determined to be 6.0, and the optimum hydrogen peroxide concentration to be 30mmol/L. Almost 100% removal of phenol (1∼10mg/L) from water was achieved by HRP membranes. For high concentrated solutions, successive cycles were successfully used to improve the degree of phenol oxidation. Furthermore, the immobilized horseradish peroxidase was operationally stable. These results suggest that the HRP membrane has promising applications for the removal of phenol. © 2016 Canadian Society for Chemical Engineering.

Chen S.,Shanghai JiaoTong University | Guo D.,Shanghai JiaoTong University | Guo B.,Shanghai Tofflon Science and Technology Co. | Liu J.,Shanghai JiaoTong University | And 4 more authors.
International Journal of Pharmaceutics | Year: 2012

A recombinant adenovirus encoding human endostatin gene, E10A, has finished phase II trials for head and neck cancer. However, the rigid storage temperature (-80 °C) and the toxicity of glycerol in the E10A liquid preparation limited its clinical application. In this study, lyophilization was applied to develop a stable E10A lyophilized powder without glycerol that is able to maintain biological activity at 4 °C and suitable for intravenous administration. The E10A lyophilized formulations composed of nontoxic and already clinically used excipients were characterized in terms of the pH change during freezing, the eutectic melting temperature (T eu) and the collapse temperature (T c). Freeze thawing tests were carried out to examine the protective effect of various excipients during freezing. Mannitol and its combinations with sucrose or inulin showed effective protection of E10A. The E10A lyophilized powders were analyzed by particle size measurement, residual humidity quantification, infectivity assay and gene expression level. An optimized formulation (formulation I1) yielded a good recovery of 76% of the starting infectivity after lyophilization and 89% of the original infectivity after storage at 4 °C for 180 days. Also the gene expression capability of E10A in formulation I1 was maintained after lyophilization. In addition, it was found that the matrix of amorphous excipients, mannitol combinations with sucrose or inulin, was indispensible in protecting E10A against the stress of freezing and dehydration. Hereby, the E10A lyophilized powder with eliminated glycerol toxicity and improved stability could enhance the applicability of E10A for cancer gene therapy through intravenous administration. © 2012 Elsevier B.V. All rights reserved.

Liu W.,Fuzhou University | Cai M.,Fuzhou University | He Y.,Fuzhou University | Wang S.,Fuzhou University | And 2 more authors.
RSC Advances | Year: 2015

A novel antibacterial polyacrylonitrile (PAN) membrane covalently immobilized with lysozyme was prepared. First, the virginal PAN membranes were prepared via the classic immersion precipitation method. After modification with NaOH, HCl, ethylenediamine (EDA), the lysozyme was covalently immobilized onto the surface of the PAN membranes by glutaraldehyde. The chemical compositions of virginal and modified membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and Energy Dispersion X-ray (EDX). The morphology and performance of the immobilized membranes were characterized by Scanning Electronic Microscopy (SEM), filtration performance measurements, the amount of bonded lysozyme, lysozyme activity measurement and flow cytometry method. The antibacterial tests confirmed that the immobilized lysozyme membrane displayed an excellent antibacterial performance against Staphylococcus aureus (S. aureus). © The Royal Society of Chemistry.

Li K.,Tianjin University | Du S.,Tianjin University | Wu S.,Tianjin University | Cai D.,Shijiazhuang Pharmaceutical Group Ou Yi Co. | And 8 more authors.
Journal of Chemical Thermodynamics | Year: 2016

In this paper, we proposed a static analysis method to experimentally determine the (solid + liquid) equilibrium of racemic oxiracetam in (methanol + water), (ethanol + water) and (isopropanol + water) binary solvents with alcohol mole fraction ranging from 0.30 to 0.90 at atmosphere pressure (p = 0.1 MPa). For the experiments, the temperatures range from (283.15 to 308.15) K. The results showed that the solubility of oxiracetam increased with the increasing temperature, while decreased with the increasing organic solvent fraction in all three tested binary solvent systems. The modified Apelblat model, the CNIBS/Redlich-Kister model, the combined version of Jouyban-Acree model and the NRTL model were employed to correlate the measured solubility values, respectively. Additionally, some of the thermodynamic properties which can help to evaluate its dissolution behavior were obtained based on the NRTL model. © 2015 Elsevier Ltd. All rights reserved.

Li D.,University of Shanghai for Science and Technology | Liu L.,University of Shanghai for Science and Technology | Yu H.,University of Shanghai for Science and Technology | Zhai Z.,University of Shanghai for Science and Technology | And 4 more authors.
Journal of Molecular Modeling | Year: 2014

Biopharmaceuticals are proteins with a crucial role in the treatment of many diseases. However, these protein medicines are often thermally labile and therefore unsuitable for long-term application and storage, as they tend to lose their activity under ambient conditions. Desiccation is one approach to improving protein stability, but the drying process itself can cause irreversible damage. In the current study, insulin was chosen as an example of a thermally sensitive biopharmaceutical to investigate whether the disaccharide, trehalose, can prevent loss of structural integrity due to drying. The experiment was performed using replica exchange molecular simulation and Gromacs software with a Gromos96 (53a6) force field. The results indicate that trehalose preserves the bioactive structure of insulin during drying, consistent with the use of trehalose as a protectant for thermally sensitive biopharmaceuticals. For instance, at the water content of 1.77 %, insulin without any protectants yields the highest RMSD value as 0.451 nm, then the RMSD of insulin in presence of trehalose only ca. 0.100 nm. © 2014, Springer-Verlag Berlin Heidelberg.

Li D.,University of Shanghai for Science and Technology | Liu B.,University of Shanghai for Science and Technology | Guo B.,Shanghai Tofflon Science and Technology Co. | Xu F.,University of Shanghai for Science and Technology | And 4 more authors.
Molecular Simulation | Year: 2013

Nowadays various protein medicines are increasingly playing a key role on treatment of many diseases, while the bioactivity of such kinds of protein medicines is unstable because of their heat sensitivity. In order to explore a protective method and to explain the protective mechanism of protein medicines, the bioactive protection of the late embryogenesis abundant (LEA) protein to insulin was researched by molecular dynamics simulation. The results suggest that LEA proteins preserve the native structure of the insulin well. Compared with the desiccated insulin without any protection, the structure of insulin protected by LEA protein have smaller values, more centralised configurational space, lower free energies and structural cluster more closer to the native structure. All the above results prove that the LEA protein does protect the bioactivity of insulin during desiccation. The LEA protein is a perfect bioactive protectant for heat-sensitive protein medicines. Such LEA proteins can match the shape of insulin and form multisite binding interaction with insulin. © 2013 Taylor & Francis.

Li D.,University of Shanghai for Science and Technology | Guo B.,University of Shanghai for Science and Technology | Liu B.,University of Shanghai for Science and Technology | Zhai Z.,University of Shanghai for Science and Technology | And 5 more authors.
Molecular Simulation | Year: 2013

Nowadays heat-sensitive protein medicines are increasingly showing their importance in the treatment of various diseases. Their popularisation and application are meeting a great challenge because of their heat lability. In this study, human insulin as a heat-sensitive protein medicine and 66 amino acids derived from a Group 3 late embryogenesis abundant protein fragment as a complex bioactive protectant, were chosen to be investigated to determine whether these amino acids can be used to protect the insulin from denaturation due to drying. The experiments were carried out by using a replica exchange molecular dynamics (REMD) simulation and GROMACS software with Gromos96 (53a6) force field. The REMD results indicate that those amino acids can effectively prevent the reversal between hydrophilic and hydrophobic surface. Both the configurations and secondary structures of the protected insulin were preserved very well. The H-bonding and electrostatic interactions between the insulin and the protectant play key roles in the bioactive protection of insulin. These results agree well with the water replacement hypothesis. All the results prove that these amino acids are a perfect bioactive protectant for heat-sensitive protein medicines. © 2013 2013 Taylor & Francis.

Loading Shanghai Tofflon Science and Technology Co. collaborators
Loading Shanghai Tofflon Science and Technology Co. collaborators