JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2023
·
IF 3.4
Ling Bai,Yanlan Zhang,Cai Zhang,Yuchen Lu,Zhiguo Li,Gang Huang,Bo Meng
A study on the polysorbate 80 stability in various formulation buffers commonly used in biopharmaceuticals was performed, to investigate the excipients influence on polysorbate 80 degradation. Polysorbate 80 is a common excipient in biopharmaceutical products. However, its degradation will potentially impact the drug product quality, and may trigger protein aggregation and particles formation. Due to the heterogeneity of the polysorbates and the mutual effects with other formulation compositions , the study of polysorbate degradation is challenging. Herein, a real-time stability study was designed and performed. The polysorbate 80 degradation trend was monitored by fluorescence micelle-based assay (FMA), reversed-phase-ultra-performance liquid chromatography-evaporative light scattering detector (RP-UPLC-ELSD) assay, and LC-MS assay. These assays provide orthogonal results to reveal both the micelle-forming capability and the compositional changes of polysorbate 80 in different buffer systems. The degradation occurred after a period of storage under 25 °C in different trend, which indicates the excipients could impact the degradation kinetics. Upon comparison, the degradation is prone to happen in histidine buffer than in acetate, phosphate or citrate buffers. LC-MS confirms oxidation as an independent degradation pathway with detection of the oxidative aldehyde. Thus, it is necessary to pay more attention to the excipients selection and their potential impact on polysorbate 80 stability to achieve longer shelf life for the biopharmaceuticals. Besides, the protective roles of several additives were figured out, which could be applied as potential industrial solutions to the polysorbate 80 degradation issues.
研究领域:
生物制药
·
药物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION SCIENCE
·
2013
·
IF 3.615
Yingqi Chen,Guojiang Wan,Juan Wang,Sheng Zhao,Yuancong Zhao,Nan Huang
Magnesium-based materials are promising in biodegradable implants, but the proper corrosion control is a challenge. Phytic acid has potential as a coating on Mg to control the degradation rate. An alkaline pre-treatment process is implemented to form the hydroxyl group on the Mg surface and covalently immobilize phytic acid. The surface-immobilized phytic acid molecules chelate with Mg to form a dense and homogenous protective coating. The coated Mg exhibits a smaller corrosion current density and degradation rate as compared to bare Mg in the phosphate buffered saline.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Fang-Nan Wu,Jian Zhu,Guo-Jun Weng,Jian-Jun Li,Jun-Wu Zhao
In this work, a tyrosine-decorated gold nanocluster (Tyr-GNC)–cerium(III) complex was established for the fluorescent detection of dopamine (DA). Tris–HCl buffer was used for synthesizing Tyr-GNC; thus, Tyr-GNC could emit fluorescence even under neutral conditions. The quantum yield (QY) of Tyr-GNC was 13.3%. Trivalent cerium ions (Ce3+) chelated hydroxyl and amino groups of tyrosine to form GNC–Ce3+. Also, DA showed a higher quenching efficiency in the fluorescence of GNC–Ce3+ than that of GNC. The mechanism was that Ce3+ chelated with DA and promoted its oxidative self-aggregation under alkaline buffer, and, at the same time, the oxidative product quenched the fluorescence of Tyr-GNC by the inner filter effect (IFE). In DA detection, GNC–Ce3+ showed a wide detection range (0.1–1000 μM) and a low detection limit (10.85 nM) for DA with high selectivity. The platform was successfully applied to DA detection in human plasma. This work proposed insight into the interaction between GNC–Ce3+ and DA, which has broad application prospects in clinical diagnosis.
研究领域:
纳米技术
·
分析化学
·
生物医学工程
·
临床诊断
✓ 已验证
产品关联
DOI
高影响因子
BIOTECHNOLOGY PROGRESS
·
2019
·Vol. 35
·期 5
·e2846
·
IF 2.406
Yanhong Chang,Shuangming Tong,Hui Luo,Zijia Liu,Bo Qin,Linlin Zhu,Hongxu Sun,Huimin Yu,Zhongyao Shen
In a stirred tank reactor, during catalysis with immobilized cephalosporin C acylase (CCA), the microenvironmental pH dropped to 7.2 in a nonbuffered system (with the pH maintained at 8.5 by adding alkali) due to the existence of diffusional resistance. Moreover, the immobilized CCA only catalyzed five batch reactions, suggesting that the sharp pH gradient impaired the enzyme stability. To buffer the protons produced in the hydrolysis of cephalosporin C by CCA, phosphate and bicarbonate buffers were introduced. When CCA was catalyzed with 0.1 M ammonium bicarbonate buffer, no obvious gradient between the bulk solution and intraparticle pH was detected, and the catalysis of 15 batch reactions was achieved. Accordingly, with 0.2 M ammonium bicarbonate buffer in a packed bed reactor, the immobilized CCA exhibited continuous catalysis with high conversion rates (≥95%) for 21 days. Reactions with ammonium bicarbonate buffer showed significant increases in the stability and catalytic efficiency of the immobilized CCA in different reactors compared to those in nonbuffered systems.
研究领域:
生物化学
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2014
·Vol. 13
·期 3
·686-690
·
IF 3.487
Yun-Zhou Ni,Wen-Feng Jiang,Gang-Sheng Tong,Jian-Xin Chen,Jie Wang,Hui-Mei Li,Chun-Yang Yu,Xiao-hua Huang,Yong-Feng Zhou
A miscible tetrahydrofuran–tris buffer mixture has been used to fabricate polydopamine hollow capsules with a size of 200 nm and with a shell thickness of 40 nm. An unusual non-emulsion soft template mechanism has been disclosed to explain the formation of capsules. The results indicate that the capsule structure is highly dependent on the volume fraction of tetrahydrofuran as well as the solvent, and the shell thickness of capsules can be controlled by adjusting the reaction time and dopamine concentration.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2018
·
IF 3.235
Wenbin Zhang,Peng Chen,Shengyou Chen,Yuyang Wei
In order to emphasize the importance of electrolyte-tuning in the nitroxyl radicals mediated electrocatalytic reactions , methanol and glycine electrooxidation reactions catalyzed by TEMPO under different properties (pH, identity, concentration) of buffer solutions were investigated by cyclic voltammetry . It was discovered that in both carbonate buffer solutions and borate buffer solutions, catalytic abilities increase with the rising of pH for both glycine electrooxidation and methanol electrooxidation. The electrocatalytic performance is also affected by the identity of buffer, for both cases of glycine and methanol, the electrooxidation activities in borate buffer solutions are apparently higher than those in carbonate buffer solutions. For both glycine and methanol electrooxidation, relationships between concentrations of carbonate ions and relative catalytic current densities were observed to be volcano-shaped, while electrocatalytic abilities increase with the increasing of concentrations of borate ions within the studied concentration range. These findings suggest that the electrolyte should be treated as important as the catalyst in the designing of nitroxyl radicals mediated electrocatalytic systems.
研究领域:
电化学
·
催化
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Yajun Hou,Shanshan Wang,Baojuan Deng,Yun Ma,Xing Long,Chengrong Qin,Chen Liang,Caoxing Huang,Shuangquan Yao
As an environmentally friendly lignocellulosic biomass separation technology, hydrothermal pretreatment (HP) has a strong application prospect. However, the low separation efficiency is a main factor limiting its application. In this study, the poplar components were separated using HP with ferric chloride and pH buffer (HFB). The optimal conditions were ferric chloride concentration of 0.10 M, reaction temperature of 150 °C, reaction time of 15 min and pH 1.9. The separation of hemicellulose was increased 34.03 % to 77.02 %. The pH buffering resulted in the highest cellulose and lignin retention yields compared to ferric chloride pretreatment (FC). The high efficiency separation of hemicellulose via HFB pretreatment inhibited the degradation of xylose . The hydrolysate was effectively reused for five times. The fiber crystallinity index reached 60.05 %, and the highest C/O ratio was obtained. The results provide theoretical support for improving the efficiency of HP and promoting its application.
研究领域:
生物质能
·
林业工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Current Analytical Chemistry
·
2023
·Vol. 19
·期 9
·685-692
·
IF 1.8
Xu Jinqiu,Gong Yinhua,Huang Rongrong,Cai Liangliang,Ma Xiaofei
Background: In borax buffer, ephedrine (EPH) and pseudoephedrine (PSE) can be well separated (Rs>10) in capillary electrophoresis (CE) without adding any other compounds, but the specific mechanism remains unclear. Methods: Titration analysis, nuclear magnetic resonance analysis,
mass spectrum analysis and molecular modeling were used to investigate the separation mechanism. Results: Tetrahydroxy borate (a hydrolyzate of borax or boric acid) could react with ephedrine and pseudoephedrine to form self-assembled complexes, but the two complexes had different stabilities
and electrophoretic mobilities resulting from the different steric configurations of analytes. Conclusion: The complexation based on borax was responsible for the separation.
研究领域:
分析化学
·
药学
✓ 已验证
DOI
高影响因子
Journal of Analytical Methods in Chemistry
·
2014
·
IF 0.948
Hongzhi Hu,Ying Liang,Shuo Li,Qing Guo,Chancui Wu
In the existence of appropriate amount of disodium ethylenediaminetetraacetate (EDTA), precipitation would not occur in seawater and other natural waters even if the sample solution was adjusted to strong basicity, and the NH3-OPA-sulfite reaction at the optimal pH range could be used to determine ammonium in natural waters. Based on this, a modified o-phthalaldehyde fluorometric analytical method has been established to determine ultratrace ammonium in natural waters. Experimental parameters, including reagent concentration, pH, reaction time, and effect of EDTA, were optimized throughout the experiments based on univariate experimental design. The results showed that the optimal pH range was between 10.80 and 11.70. EDTA did not obviously affect the fluorometric intensity. The linearity range of the proposed method was 0.032–0.500 µmol/L, 0.250–3.00 µmol/L, and 1.00–20.0 µmol/L at the excitation/emission slit of 3 nm/5 nm, 3 nm/3 nm, and 1.5 nm/1.5 nm, respectively. The method detection limit was 0.0099 µmol/L. Compared to the classical OPA method, the proposed method had the advantage of being more sensitive and could quantify ultratrace ammonium without enrichment.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
TALANTA
·
2021
·
IF 6.057
Ping Sun,Jing Wu,Shenghong Yang,Hongli Li,Lei Zhao,Yuanhang Wang,Xiayan Wang,Qiaosheng Pu
Microchip capillary electrophoresis (MCE) is a powerful technique for rapid separation; however, its acceptance in routine laboratories is still limited. Compromises caused by the efforts for solving different problems, such as reducing its cost of fabrication and ensuring high separation efficiency, undermine the competitiveness of this technology compared to other separation techniques. Contrary to the conventional pursuit of narrow microchannels, this study investigated the suitability of microchips with channels at the sub-millimeter level, targeting the simplification of the overall operation, cost reduction, and robustness improvement. To this effect, we considered the influence of pressurized flow and Joule heating on the separation. The suppression of pressurized flow with viscous solutions was confirmed through a combination of simulations and experimental results, indicating that the buffer viscosity was enough for successful separation. We fabricated channels of 200 μm × 230 μm using computer numerical controlled (CNC) machining and obtained theoretical plate numbers of 4.8 × 10 5 m −1 and 5.3 × 10 5 m −1 for fluorescein isothiocyanate (FITC) labeled small molecules and DNA fragments, respectively, with a buffer viscosity of 168 mPa s (0.5 % hydroxypropyl methylcellulose , HPMC). These values are comparable with that of narrow-bore microchips. Furthermore, we did not observe any deleterious effects with low-conductivity buffers. We investigated the rapid and highly sensitive detection of mycoplasma contamination and the real samples of circulating cell-free DNA (cfDNA), which gave a limit of detection (LOD) as low as 2.3 ng mL −1 . Owing to the significant reduction in cost, ease of operation, and fast separation capabilities demonstrated in this work, MCE can be a viable alternative to the usual slab gel electrophoresis running in most biological laboratories.
研究领域:
分析化学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHROMATOGRAPHIA
·
2014
·Vol. 78
·期 1
·119-123
·
IF 1.37
Yang Xiujuan,Liu Cui,Chen Zuanguang
A novel and rapid method was developed for the determination of uric acid in human urine by capillary electrophoresis with an improved electromagnetic induction detector. Electrophoretic parameters affecting the separation efficiency, such as buffer composition, buffer pH, buffer concentration, and electroosmotic flow modifier, were systematically investigated. An electrolyte solution consisting of 8.5 mmol L −1 tris(hydroxymethyl)aminomethane (Tris), 1.5 mmol L −1 citric acid, and 0.2 mmol L −1 cetyltrimethylammonium bromide, pH 8.0, was found to be suitable for sample determination. Uric acid was separated and detected within 2.3 min, with a linear response range from 5 to 400 µg mL −1 and a correlation coefficient of 0.9998. Intraday and interday precision were 1.6 and 2.5 % ( n = 6), respectively. The recoveries were between 98.3 and 100.5 %. This simple, effective, and stable method is a good alternative to existing methods for uric acid determination. Also, the improved electromagnetic induction detector holds great promise in clinical analysis.
研究领域:
分析化学
·
临床分析
·
电泳技术
✓ 已验证
DOI
高影响因子
Nano Energy
·
2020
·
IF 16.602
Meirong Huang,Zhiwei Huang,Hongwei Zhu
Solar-driven photoelectrochemical water splitting is a promising solution to energy problem. However, not-yet-available long-term stability of photoelectrodes inhibits their practical application. Introducing structure tunable, highly active and easily prepared molecular catalysts is an efficient approach to improve their stability and has recently attracted great attention. Nonetheless, the long-term stability is still challenged due to regeneration of molecular catalyst during stability test. Herein, tannic acid coordinated with Ni and Fe ions (TANF) molecular catalyst is immobilized on BiVO 4 photoanode for oxygen evolution reaction (OER). Taking advantage of the regeneration of molecular catalyst, effects of buffer species on activity, stability and regeneration of TANF/BiVO 4 photoanodes are investigated. In an optimal borate electrolyte, the TANF/BiVO 4 photoanode shows nearly no-decay after operating at harsh conditions (at 1.2 V RHE with continuous light illumination) for 62 h. The long-term stability profits from the regenerated catalyst, which is composed of a carbon conductive network with metal oxides/hydroxides as OER-active sites. This excellent stability of the integrated photoanode surpasses most of existing OEC/BiVO 4 photoanodes, and the stabilized catalyst is comparable with the state-of-the-art FeOOH/NiOOH dual-cocatalyst and ferrihydrite catalyst.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）