无定形药物固相表征技术的研究进展及应用

无定形药物在提高难溶性药物溶解度、改善其溶出及生物利用度方面具有显著优势,故而广泛应用于药物制剂领域。但无定形药物处于能量较高的非稳态,易发生结晶,从而失去其在溶解度和溶出速率等方面的优势。因此,在无定形药物制剂的制备和储存过程中,为控制质量需要对其进行相应表征。目前,已有包括光学技术、热分析技术、光谱学技术等在内的多种技术被广泛用于无定形药物制剂的研究领域。本文简述无定形药物制剂的多种新发展的表征技术,包括偏光显微镜-控温热台联用、表面光栅衰减、X射线粉末衍射-同步辐射光源技术联用、热分析技术、宽频介电谱、纳米红外光谱分析、拉曼光谱成像、固态核磁共振、荧光分析、X射线光电子能谱等技术,并重点介绍近几年该领域的研究进展及其应用,以期为无定形药物制剂研究和开发提供借鉴。     

Enzyme assays for confocal single molecule spectroscopy

During the last years confocal techniques have become increasingly popular for probing biological enzymatic reactions. In this paper we will summarize some of these methods, mainly focusing on measurement techniques suitable for analysis of freely diffusing molecules, where either the substrates or the enzymes are fluorescently labeled. The different approaches are classified according to their basic principles and algorithms. Several examples of enzymatic studies involving correlation strategies for data processing, like auto- and cross correlation analysis, will be presented. In addition, other evaluation schemes like coincidence analysis and fluorescence intensity distribution analysis are introduced and discussed. With respect to assay development, the fluorescence energy transfer principle is addressed as far as it is has been applied for investigating biocatalysis in solution. Finally, one part of this review addresses the aspects of bioconjugation and the basic requirements for proper labeling dyes in order to be compatible with single molecule fluorescent spectroscopy.     

Three ‘D’s: Design approach,dimensional printing,and drug delivery systems as promising tools in healthcare applications

The development of pharmaceutical drug products is required for the treatment of disease, which has resulted in an increasing number of approvals by regulatory agencies across the globe. To establish a hassle-free manufacturing process, the systematic use of a quality-by-design (QbD) approach combined with process analytical technology (PAT) and printing techniques can revolutionize healthcare applications. Printing technology has been emerged in various dimensions, such as 3D, 4D, and 5D printing, with respect to their production capabilities, durability, and accuracy of pharmaceutical manufacturing, which can efficiently deliver novel patient-centric healthcare products with holistic characteristics. In this review, we provide current trends in pharmaceutical product development using a design approach and high-quality printing techniques.     

基于LC-MS的代谢组学分析流程与技术方法

代谢组学是继基因组学、转录组学、蛋白质组学之后兴起的又一新的组学研究分支,但其研究技术方法一直以来都是影响代谢组学发展的瓶颈之一。超高效液相色谱-质谱联用（UPLC-MS）技术结合化学计量学比较好地实现了对大量样品和微量代谢物的快速定性、定量分析,极大地推动了代谢组学的发展。本文按照代谢组学分析流程综述了LC-MS与化学计量学相结合用于代谢组学研究的现状与进展,并对重要研究方向进行了简要展望。     

Hard and soft micromachining for BioMEMS: review of techniques and examples of applications in microfluidics and drug delivery

Recent development in microfabrication (micromachining, microelectromechanical systems, MEMS) permits the integration of hard and soft structures, and enables the design of controllable microfluidic systems, which may be applied to drug delivery. In this paper, we present a tutorial review of both classical "hard" and more recent "soft" micromachining techniques. We then provide examples where these techniques are combined to produce hydrogel-based microfluidic control systems. The most complex of these systems utilizes a very small hydrogel based on phenylboronic acid to control the flow of an insulin solution in response to changes in glucose concentration.     

A review status on characterization and electrochemical behaviour of biomass derived carbon materials for energy storage supercapacitors

Carbon materials have been used as potential electrode for supercapacitor applications and this review focused on status of maximum biomass derived carbon precursors with or without external activation in the application of supercapacitors, understanding the aspects of porous carbon materials derived from various biomass which are incorporated as electrodes for supercapacitors. This review highlights the production of activated carbon from waste biomass and also deals with their characterization techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy (RAMAN), field emission scanning microscopy (FESEM), Transmission electron microscope (TEM) and their impacts on electrochemical performance of galvanostatic charge discharge analysis (GCD) and cyclic stability test in the application of supercapacitors.     

G蛋白偶联受体高阶聚化和信号转导中蛋白复合体的时空动态检测进展

传统观点认为,G蛋白偶联受体与G蛋白、调节蛋白、GRKs以及arrestins间的相互作用是连续的,其中涉及多个蛋白质之间快速的集合和解聚。而实际上,GPCRs和相关靶分子之间的作用是通过一系列细胞内蛋白质-蛋白质相互作用的信号转导网络来实现的。近10年,随着一些新兴技术的出现,如FRET、BRET和BiFC,实时动态观测二个蛋白质间相互作用的研究成为热点。最近,一些技术结合的方法为从"时间、空间、动态、连续"检测更多蛋白质之间的相互作用的研究拉开新的帷幕。从横向来看,这些技术的结合可以用来研究细胞膜上3种甚至更多蛋白质的高阶寡聚化;从纵向来看,可以对细胞膜-细胞质-细胞核中所发生的信号转导网络的研究提供新的技术手段,多种技术结合所发挥作用是最近出现的几种技术所无法企及的,这对于疾病发病机制的研究及新的药物靶点的发现具有深远意义。因此,本文就一些技术的结合及其应用做一简要综述。     

Preclinical (1)H-MRS neurochemical profiling in neurological and psychiatric disorders

The ongoing development of animal models of neurological and psychiatric disorders in combination with the development of advanced nuclear magnetic resonance (NMR) techniques and instrumentation has led to increased use of in vivo proton NMR spectroscopy ((1)H-MRS) for neurochemical analyses. (1)H-MRS is one of only a few analytical methods that can assay in vivo and longitudinal neurochemical changes associated with neurological and psychiatric diseases, with the added advantage of being a technique that can be utilized in both preclinical and clinical studies. In this review, recent progress in the use of (1)H-MRS to investigate animal models of neurological and psychiatric disorders is summarized with examples from the literature and our own work.     

Raman spectroscopy using plasmonic and carbon-based nanoparticles for cancer detection,diagnosis, and treatment guidance.Part 1: Diagnosis

Optical techniques, including Raman, photothermal and photoacoustic microscopy and spectroscopy, have been intensively explored for the sensitive and accurate detection of various diseases. Rapid advances in lasers, photodetectors, and nanotechnology have led to the development of Raman spectroscopy, particularly surface-enhanced Raman scattering (SERS), as a promising imaging modality that can help diagnose many diseases. This review focuses on the major recent advances in Raman spectroscopy and SERS-enhancing contrast nanoagents, as well as their potential to transition from a proof-of-concept approach to a cancer detection tool in vitro and in vivo.     

Fluorescence anisotropy and resonance energy transfer: powerful tools for measuring real time protein dynamics in a physiological environment

Fluorescence spectroscopy/microscopy is a versatile method for examining protein dynamics in vitro and in vivo that can be combined with other techniques to simultaneously examine complementary pharmacological parameters. The following review will highlight the advantages and challenges of using fluorescence spectroscopic methods for examining protein dynamics with a special emphasis on fluorescence resonance energy transfer and fluorescence anisotropy. Both of these methods are amenable to measurements on an ensemble of molecules as well as at the single molecule level, in live cells and in high throughput screening assays, providing a powerful set of tools to aid in the design and testing of new drugs under a variety of experimental conditions.     

Determination of polymorphic forms of ranitidine-HCl by DRIFTS and XRPD

The identification, characterization and quantification of crystal forms are becoming increasingly important within the pharmaceutical industry. A combination of different physical analytical techniques is usually necessary for this task. In this work solid-state techniques, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray powder diffractometry (XRPD) were combined to analyze polymorphic purity of crystalline ranitidine–HCl, an antiulcer drug, H2 receptor antagonists. A series of 12 different mixtures of Form 1 and 2 was prepared by geometric mixing and their DRIFT spectra and XRD powder patterns were obtained and analyzed, either alone or combined together, using Artificial Neural Networks (ANNs). A standard feed-forward network, with back-propagation rule and with multi layer perceptron architecture (MPL) was chosen. A working range of 1.0–100% (w/w) of crystal Form 2 in Form 1 was established with a minimum quantifiable level (MQL) of 5.2% and limit of detection of 1.5% (w/w). The results demonstrate that DRIFTS combined with XRPD may be successfully used to distinguish between the ranitidine–HCl polymorphs and to quantify the composition of binary mixtures of the two.     

Vertebrate membrane proteins: structure, function, and insights from biophysical approaches

Membrane proteins are key targets for pharmacological intervention because they are vital for cellular function. Here, we analyze recent progress made in the understanding of the structure and function of membrane proteins with a focus on rhodopsin and development of atomic force microscopy techniques to study biological membranes. Membrane proteins are compartmentalized to carry out extra- and intracellular processes. Biological membranes are densely populated with membrane proteins that occupy approximately 50% of their volume. In most cases membranes contain lipid rafts, protein patches, or paracrystalline formations that lack the higher-order symmetry that would allow them to be characterized by diffraction methods. Despite many technical difficulties, several crystal structures of membrane proteins that illustrate their internal structural organization have been determined. Moreover, high-resolution atomic force microscopy, near-field scanning optical microscopy, and other lower resolution techniques have been used to investigate these structures. Single-molecule force spectroscopy tracks interactions that stabilize membrane proteins and those that switch their functional state; this spectroscopy can be applied to locate a ligand-binding site. Recent development of this technique also reveals the energy landscape of a membrane protein, defining its folding, reaction pathways, and kinetics. Future development and application of novel approaches during the coming years should provide even greater insights to the understanding of biological membrane organization and function.     

Headspace microextraction: recent bioanalytical applications and issues

Headspace microextraction has already been established as the method of choice for analyzing volatiles blended in complex matrices, such as environmental, food and biological samples. The modern trend of analytical chemistry for 'going small' has led to the successful development of various sorbing materials and microextraction techniques. As it is anticipated, microextraction is usually combined with powerful separation and optical techniques permitting enhanced recoveries of analytes, selectivity and sensitivity. In addition, derivatization reactions are often employed for improved detectability of several classes of compounds. Volatile compounds of biological significance are key substances due to the fact that they may constitute a characteristic of the status of the organism. A closer look at the biological applications of the headspace microextraction techniques (solid-phase and single drop microextraction) is the primary aim of this review. The variability of biological samples and analytes are considered primarily, while derivatization and optimization strategies are also discussed.     

Microcoil nuclear magnetic resonance spectroscopy

In comparison with most analytical chemistry techniques, nuclear magnetic resonance has an intrinsically low sensitivity, and many potential applications are therefore precluded by the limited available quantity of certain types of sample. In recent years, there has been a trend, both commercial and academic, towards miniaturization of the receiver coil in order to increase the mass sensitivity of NMR measurements. These small coils have also proved very useful in coupling NMR detection with commonly used microseparation techniques. A further development enabled by small detectors is parallel data acquisition from many samples simultaneously, made possible by incorporating multiple receiver coils into a single NMR probehead. This review article summarizes recent developments and applications of “microcoil” NMR spectroscopy.     

Facts, figures and trends in lead generation

The goal of this paper is to review the variety of approaches adopted to improve lead generation, and make the process easier for the chemist, faster and more likely to succeed in later phases of drug development. Our analysis shows that successful lead generation requires not only an accurate definition of the needs (to define the most relevant assay protocols and readouts), but most of all a good hit as a starting point. It also appears that teams where techniques are combined are more successful in that difficult game.     

Structural studies on FK-506, cyclosporin A and their immunophilin complexes

Summary The immunosuppressants FK-506 and cyclosporin A (CsA), along with their macromolecular receptors FKBP12 and cyclophilin A (CyPA), have become important targets for structure-based drug design. In the last few years X-ray diffraction and NMR spectroscopy have combined to provide high-resolution structures of FK-506, CyA, FKBP12, CyPA, FKBP12-FK-506, CyPA-CyA, and other complexes. This review summarizes these structural studies and some of their implications. Because the immunosuppressant-immunophilin complex forms a composite binding surface that interacts with yet another protein, structure-based drug design in this area is unusually challenging.     

Recent advances in bioanalytical sample preparation for LC-MS analysis

Sample preparation has historically been, and continues to be, the most challenging part of the bioanalytical workflow. Several techniques have been developed over the years to deal with the problems of recovery and matrix effects in an effort to increase the reliability and robustness of the bioanalytical method. In recent years certain techniques have come into prominence and gained acceptance in routine sample preparation, and some have shown promise in their use in a discovery environment where speed is critical and method development time is often limited. The aim of this review is to examine several of these techniques and provide examples of their use from the literature, as well as comment on their utility in current workflows.     

Raman microscopy for cellular investigations — From single cell imaging to drug carrier uptake visualization

Progress in advanced therapeutic concepts requires the development of appropriate carrier systems for intracellular drug delivery. Consequently, analysis of interaction between carriers, drugs and cells as well as their uptake and intracellular fate is a current focus of research interest. In this context, Raman spectroscopy recently became an emerging analytical technique, due to its non-destructive, chemically selective and label-free working principle.In this review, we briefly present the state-of-the-art technologies for cell visualization and drug internalization. Against this background, Raman microscopy is introduced as a versatile analytical technique. An overview of various Raman spectroscopy investigations in this field is given including interactions of cells with drug molecules, carrier systems and other nanomaterials. Further, Raman instrumentations and sample preparation methods are discussed. Finally, as the analytical limit is not reached yet, a future perspective for Raman microscopy in pharmaceutical and biomedical research on the single cell level is given.