细胞色素P450酶电化学生物传感器的构建及其药物代谢应用

药物代谢过程是药物在体内产生药效和毒性的主要过程,发展廉价、方便、快速、高通量的体外药物代谢研究方法对新药的开发和设计、给药的方法和剂量、临床药物的检测等都有重要的指导意义. 细胞色素P450酶（CYP450酶）在药物的I相反应中起到关键作用,以电极代替辅酶NADPH提供CYP450酶催化反应过程中需要的两个电子,构建CYP450酶电化学生物传感器可实现药物的初步筛选. 大量研究表明,CYP450酶在电极表面合适的固定方法与电极材料可有效提高传感器的检测性能. 本文主要综述近年来CYP450酶电化学生物传感器的构建及其在药物代谢研究方面的应用,并展望其研发前景.     

活细胞毒素纳米探测器近日问世

美国科学家最近开发出一个微型纳米探测器,能够探测活细胞中的致癌毒素或追踪癌症药物的效用。这是一个追踪身体内特定化学药物的全新工具。该研究成果发表在2008年12月14日的《自然.纳米技术》杂志上。研究人员把碳纳米管植入DNA分子内制成传感器,以便置入活细胞内。该传感器可以探测多种特定的损害DNA的物质,比如某些毒素分子、自由基以及一些癌症化疗药物分子。它能定位这些分子在细胞内的准确位置,尤其对于过氧化氢这种氧化剂,其探测精度可以达到单个分子。美国麻省理工学院研究小组开发的传感器将成型的碳纳米管与DNA包裹在一起,使其能与细胞内损伤DNA的“代理”相结合。该传感器能发出可在近红外线光谱附近被探测到的荧光,因为人体组织在这个光谱内不会发光,纳米管因此显得很突出。当传感器同细胞内的DNA相互作用时,光信号发生变化,这些变化能够帮助研究人员识别特定的分子。因为该传感器被涂在DNA内,它们能够被安全地注射进活细胞内。最终,细胞吞噬掉涂层表面的蛋白质,探测器就能“脱颖而出”。这种细胞“探测器”可用于癌症患者的化疗监测,确保化疗药物有效发挥作用。研究人员解释说,有很多化疗药物都会对细胞内的DNA产生极强的破坏力,引发严重副...     

药物敏感场效应晶体管测定阿托品的研究

报道了一种测定阿托品的新方法。用四苯硼钠为电活性物质 ,将离子敏感场效应晶体管与药物敏感膜相结合 ,制成药物敏感场效应晶体管传感器。该传感器测定阿托品的线性范围为 1 .0× 1 0 - 2～ 8.5× 1 0 - 6 mol/L。用该传感器分析阿托品针剂 ,结果与药典法吻合     

金属纳米颗粒的制备及其在酶生物传感器中的应用研究

近年来,金属纳米颗粒的制备研究引起了人们的广泛兴趣.与相应的块体材料相比,金属纳米颗粒具有独特的化学和物理性质,可应用于电学、催化、磁性材料、光催化、生物染色剂、药物输送等许多领域.其中,传感器是纳米颗粒最有前途的应用领域之一.传感器的微型化是传感器发展的主要研究方向,将纳米颗粒用于传感器的研究将促进这一目标的实现.本论文利用纳米颗粒材料的独特效应来提高葡萄糖传感器的响应电流.将自制的银金、铂以及二氧化硅和铂复合纳米颗粒用于固定化酶,使酶电极的电流响应值得到了大幅度的提高,从而为纳米增强的新型葡萄糖生物传感器的研究、制备和应用提供了可供参考的实验和理论依据,并为传感器的小型化开辟了一条新途径.     

可穿戴光谱传感器在医疗监测中的研究进展

可穿戴光谱传感器是一种由柔性衬底、传感及检测分析单元组成的一体化智能器件,能够无创或微创地对汗液、经皮气体、伤口分泌物、皮下间质液、泪液、呼出气和唾液等人体生理体液中的化学物质进行快速检测和实时跟踪,在药物分析、疾病诊断及健康监测等领域中具有重要意义。本文总结了2016年以来可穿戴比色、荧光及表面增强拉曼散射传感器的研究概况,基于可穿戴光谱传感器的组成,综述了表皮、眼部及口部形式的可穿戴光谱传感器的研究进展,并分析了可穿戴光谱传感器未来发展面临的挑战及机遇,以期为可穿戴光谱传感器的设计和开发提供参考。     

核壳结构三维有序水凝胶的制备

随着科学技术的发展 ,人们不断地寻求具有新特性、新功能的高分子材料 .聚合物凝胶作为一种智能高分子材料 ,受到极大的关注[1,2 ] .聚合物凝胶具有外场响应特性 ,其体积可随外界环境如溶剂、温度、电场、磁场、ｐＨ值、化学物质或光照等条件的改变而变化 ,因而在药物可控释放、吸附分离及传感器等方面具有潜在应用价值 .对聚合物凝胶进行图案化处理 ,使之成为有序结构 ,大大拓宽了凝胶的应用范围 .Ｈｕ等[3 ,4 ] 首先报道了环境响应水凝胶表面图案的调控技术 ,图案的特征尺寸在微米级 ,此类凝胶作为光栅 ,在光纤、传感器和光通信中具有潜在…     

基于荧光聚合物的光纤传感器测定四环素的研究

将甲基丙烯酸 [9]蒽甲基酯与甲基丙烯酸甲酯、丙烯酸丁酯共聚 ,制备了一种含蒽的荧光共聚物 (PAMB) ,基于四环素 (TC)对PAMB共聚物膜荧光的可逆猝灭作用 ,研制了一种测定TC的荧光光纤传感器。在 2 .0 2× 10 - 7～ 2 .0 2× 10 - 4mol·L- 1TC浓度范围内有良好的线性关系。该传感器对TC的响应灵敏度高 ,选择性好 ,响应和恢复时间均小于 30s ,碱金属、碱土金属离子及常用药物对TC测定没有干扰。将传感器应用于TC药物样品的测定 ,结果良好     

扑尔敏ISFET化学传感器的研制与应用

以苯并 15 冠 5作为电活性物质 ,邻苯二甲酸二辛酯作增塑剂 ,制成了PVC膜药物敏感场效应晶体管化学传感器 ,该传感器对扑尔敏的线性响应范围为 0 .5～ 3.0× 10 - 6mol·L- 1,具有较好的选择性、稳定性和重现性。用该传感器对扑尔敏进行测定 ,分析结果与标准方法相同     

基于壳聚糖-二茂铁/碳纳米管传导复合物的无标记安培型免疫传感器

免疫传感器是将免疫测定法与高灵敏的传感技术相结合而构建的一类新型生物传感器,应用于痕量免疫原性物质的分析研究.在各类免疫传感器研究中,安培型免疫传感器因其高灵敏度和简单的仪器设备引起了国内外许多学者的兴趣~([2]).然而,抗原和抗体没有电活性,通常需要对抗原或抗体进行步骤复杂的标记以制备安培型免疫传感器,并提高传感器的检测灵敏度.     

基于适体和生物条形码放大技术多组分电化学生物传感器的研究

适体(Aptamer)也称为核酸适体、适配体、适配子等,是一段由25～80个碱基组成的单链寡核苷酸片段,可以是DNA也可以是RNA~([1,2]).它是通过指数富集配体系统进化(SELEX)技术从人工构建的随机单链寡核苷酸文库里筛选出来,可以结合蛋白质、氨基酸、药物或无机离子等目标分子.适体作为传感器的分子识别物质与其它分子识别物质相比,具有高特异性、高亲和力、目标分子范围广、稳定性好等优点,广泛用于生物传感器的研究~([3]).     

Vinyl Ether/Tetrazine Pair for the Traceless Release of Alcohols in Cells

The cleavage of a protecting group from a protein or drug under bioorthogonal conditions enables accurate spatiotemporal control over protein or drug activity. Disclosed herein is that vinyl ethers serve as protecting groups for alcohol‐containing molecules and as reagents for bioorthogonal bond‐cleavage reactions. A vinyl ether moiety was installed in a range of molecules, including amino acids, a monosaccharide, a fluorophore, and an analogue of the cytotoxic drug duocarmycin. Tetrazine‐mediated decaging proceeded under biocompatible conditions with good yields and reasonable kinetics. Importantly, the nontoxic, vinyl ether duocarmycin double prodrug was successfully decaged in live cells to reinstate cytotoxicity. This bioorthogonal reaction presents broad applicability and may be suitable for in vivo applications.     

Novel approach to DPI carrier lactose with mechanofusion process with additives and evaluation by IGC

The effect of lactose carrier surface property on the inhalation profile of dry powder inhaler (DPI) was evaluated using a micronized drug (Compound A) by inverse gas chromatography (IGC). Mechanofusion with magnesium stearate (Mg-St) or sucrose stearate increased the fine particle fraction (FPF), considered to be due to decrease in the interaction between Compound A and the lactose carrier. The effect of Compound A concentration on FPF was smaller in mechanofusion-processed lactose compared to intact lactose, especially when processed with Mg-St. The relationship between the IGC parameters of the lactose and FPF was also investigated. FPF increased as both the dispersive component of the surface energy and acidity similarity between the lactose carriers and Compound A increased. Although further investigation is necessary, it could be suggested that acidity similarity decreases the interaction between Compound A and lactose, thus contributing to the increase in the FPF. In conclusion, (1) mechanofusion with Mg-St or sucrose stearate could be an effective method to improve FPF of a DPI drug formulation; (2) IGC would be a valuable method to investigate the interaction between a drug and the DPI carrier; and (3) a relationship between surface acidity and inhalation profile was suggested.     

Ultra-low flow nanospray for the normalization of conventional liquid chromatography/mass spectrometry through equimolar response: standard-free quantitative estimation of metabolite levels in drug discovery

Nanospray experiments were performed on an ensemble of drug molecules and their commonly known metabolites to compare performance with conventional electrospray ionization (ESI) and to evaluate equimolar response capabilities. Codeine, dextromethorphan, tolbutamide, phenobarbital, cocaine, and morphine were analyzed along with their well-known metabolites that were formed via hydroxylation, dealkylation, hydrolysis, and glucuronidation. Nanospray exhibited a distinct trend toward equimolar response when flow rate was reduced from 25 nL/min to less than 10 nL/min. A more uniform response between the parent drug and the corresponding metabolites was obtained at flow rates of 10 nL/min or lower. The largest discrepancy was within +/-50% for plasma samples. Nanospray was used as a calibrator for conventional ESI liquid chromatography/tandem mass spectrometry (LC/MS/MS) and normalization factors were applied to the quantitation of an acyl-glucuronide metabolite of a proprietary compound in rat plasma. A nanospray calibration method was developed with the standard curve of the parent drug to generate quantitative results for drug metabolites within +/-20% of that obtained with reference standards and conventional ESI. The nanospray method provides a practical solution for the quantitative estimation of drug metabolites in drug discovery when reference standards are not available.     

高效液相色谱手性流动相法拆分甲状腺素对映体

运用高效液相色谱手性流动相法（ＨＰＬＣ－ＣＭＰ）对影响甲状腺素对映体（Ｄ－,Ｌ－Ｔ４）分离方法的因素：三乙胺（ＴＥＡ）浓度,流动相ｐＨ值,铜离子（Ｃｕ２＋）浓度,Ｌ－脯氨酸（Ｌ－ｐｒｏ）浓度,柱温以及流动相的流速进行了系统的研究。同时,考察了色谱方法分离Ｔ４对映体的线性关系,精密度和准确度。线性响应范围为０．６～３．２　ｎｍｏｌ　（Ｄ－,Ｌ－Ｔ４）,线性相关系数为ｒＤ－Ｔ４＝０．９９８０,ｒＬ－Ｔ４＝０．９９９０,日内和日间的精密度分别为ＲＳＤ＜２．３％（ｎ＝６）,ＲＳＤ＜３．１５％（ｎ＝５）。结果表明本实验所得的色谱条件较文献报道的优越,分离条件简单,重现性好。ＨＰＬＣ－ＣＭＰ法测定甲状腺素对映体其意义在于该方法可为定量测定药品及人体血液中Ｄ－,Ｌ－Ｔ４两种异构体,为治疗药物监测（ＴＤＭ）和药物不良反应监测（ＡＤＲｓ）提供了依据。     

In Vitro Release of Local Anaesthetic and Anti-Inflammatory Drugs from Crosslinked Collagen Based Device

The drug delivery systems that are the object of this article take the form of a hydrophilic matrix (collagen or crosslinked collagen) containing a drug. These devices can be used as The model active agents, were chosen from the range of local anaesthetics (lidocaine hydrochloride), anti-inflammatory (diclofenac sodium salt) and antioxydant (caffeic acid). Whatever the drug affinity for water, in the first time of the experiments, the release appears to be systematically delayed when the matrix is crosslinked. For lidocaine hydrochloride based systems, as the amount of drug increases in the matrix, the high gap concentration between the matrix and the buffer solution promote the diffusion and a Fickian behavior is observed on the release curves. Depending on the chemical nature of the drug and its solubility, several interactions between the drug and the collagen matrix can be considered. A new drug delivery system containing caffeic acid as the anti-inflammatory and antioxydant molecule could be tested. This new system was able to release 95% of the drug in 5 h and the global release rate depends on the initial drug concentration in the device.     

Eudragit as controlled release system for anti-inflammatory drugs: A comparison between DSC and dialysis experiments

A comparative study between the release of Ibuprofen (IBU) from Eudragit RS100^® (RS) and RL100^® (RL) nanosuspensions as well as the free drug to a biological model membrane, consisting of dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV), was carried out by DSC technique. The aim was to assess the suitability of such calorimetric technique to determine the kinetics of drug release from a polymer system, compared with a classical release test by dialysis method. Nanosuspensions were prepared by a modification of the quasi-emulsion solvent diffusion technique (QESD), a particular approach to the general solvent-change method. This kind of system was planned for the ophthalmic release of non-steroidal anti-inflammatory drugs in ocular diseases associated with inflammatory processes (i.e. post-cataract surgery or uveitis). The drug release was monitored by differential scanning calorimetry (DSC), following the effects exerted by IBU on the thermotropic behaviour of DMPC multilamellar vesicles. IBU affects the main transition temperature (T_m) of phospholipid vesicles, causing a shift towards lower values, driven by the drug fraction entering the lipid bilayer. The obtained values have been used as a calibration curve. DSC was performed on suspensions of blank liposomes added to fixed amounts of unloaded and IBU-loaded Eudragit RS100^® and RL100^® nanosuspensions as well as to powdered free drug. The T_m shifts caused by the drug released from the polymer system or by the free drug, during incubation cycles at 37 °C, were compared to the calibration curve in order to obtain the fraction of drug released. The results were also compared with in vitro dialysis release experiments. The suitability of the two different techniques to follow the drug release as well as the differences between the RL and RS polymer systems was compared, confirming the efficacy of DSC for studying the release from polymer nanoparticulate systems. Explanation of the different rate of kinetic release could be due to void liposomes, which represent a better up-taking system than the aqueous solution phase in the dialysis experiments.     

Liquid Chromatographic Assay for Amodiaquine in Tablets and Biological Fluids

Abstract

A high performance liquid chromatographic assay for quantitating amodiaquine (A) in tablets, urine, plasma, bile and saliva is described. The method involved acid extraction of the drug from tablets and chloroform extraction of its base from the biological fluids after alkalinization with ammonia. Quinidine was used as the internal standard. A μ-Bondapak phenyl column was used for separation together with a mobile phase made of methanol, water and glacial acetic acid (pH 2.3). Good chromatograms with efficient separation of drug and internal standard peaks were observed. Retention times of 5.2 and 7.1 min. were obtained for the drug and the internal standard respectively. Correlation between areas under the curve and drug concentration was high. The mean percentage recovery of A from tablets was 102.03%, while from the biological fluids, it ranged from 85.2 to 104.61%. Urine and saliva obtained from volunteers and bile obtained from animals administering amodiaquine showed chromatograms similar to those obtained for blank samples spiked with A. Interference from table't excipients of biological fluids was undetectable or negligible. The method was found to be precise and simple.     

Determination of paramethoxyamphetamine and other amphetamine-related designer drugs by liquid chromatography/sonic spray ionization mass spectrometry

Paramethoxyamphetamine (PMA) is an amphetamine-like designer drug that has emerged recently on the European illicit drug market. This drug has a wicked reputation, as a number of lethal intoxications have occurred. A method using high-performance liquid chromatography coupled to ion trap based mass spectrometry (LC/MS) is described for the determination of this compound together with 3,4-methylenedioxymethamphetamine (XTC or MDMA), amphetamine and 3,4-methylenedioxyamphetamine (MDA) in human matrices. A liquid/liquid extraction (LLE) was applied to whole blood, urine and postmortem tissues. Reversed-phase liquid chromatography was performed on a narrow-bore phenyl-type column at a flow rate of 0.3 mL/min. A switch box allowed disposal of early-eluting irrelevant material to waste, protecting the mass spectrometer from contamination. The column effluent was directed into an ion trap mass spectrometer by a sonic spray ionization (SSI) interface. The method was validated for all three matrices, proving the applicability of SSI even when dealing with complex biological matrices. The within-and between-day precisions were less than 17.5% and accuracy was below 16.2%. Weighted (1/x) quadratic calibration curves were generated ranging from 10 to 1000 ng/mL (blood and urine) or 20 to 2000 ng/g (tissue) and correlation coefficients (r(2)) always exceeded 0.995. In addition, the mass spectrum of PMA is given together with a proposed fragmentation pattern for the obtained LC/MS spectrum. This information can be useful for future identification of PMA with LC/MS in biological matrices as well as in confiscated powders or tablets.     

An ant algorithm for the conformational analysis of flexible molecules

Originally, the ant system was developed for optimization in discrete search spaces such as the traveling salesman problem. We detail our adaptation of the algorithm to optimization in the continuous search space of conformational analysis. The parameters of the algorithm were tuned using a simple test molecule, undecane, and a drug molecule, imatinib. The algorithm is further tested on four more drug or drug-like molecules, on vitamin A and on alanine tetrapeptide.     

Fluorescent Protein Capped Mesoporous Nanoparticles for Intracellular Drug Delivery and Imaging

A multifunctional system for intracellular drug delivery and simultaneous fluorescent imaging was constructed by using histidine‐tagged, cyan fluorescent protein (CFP)‐capped magnetic mesoporous silica nanoparticles (MMSNs). This protein‐capped multifunctional nanostructure is highly biocompatible and does not affect cell viability or proliferation. The CFP acts not only as a capping agent, but also as a fluorescent imaging agent. The nanoassembly was activated by histidine‐based replacement, leading to release of drug molecules encapsulated in the nanopores into the bulk solution. The fluorescent imaging functionality would allow noninvasive tracking of the nanoparticles in the body. By combining the drug delivery with cell‐imaging capability, these nanoparticles may provide valuable multifunctional nanoplatforms for biomedical applications.