可穿戴式微流控芯片在体液检测和药物递送中的研究进展

可穿戴式微流控芯片在医疗、体育、军事等领域具有广泛的应用潜力,利用可穿戴式微流控芯片对人体体液进行实时监测,可以通过芯片与皮肤的接触,方便地对汗液、泪液、唾液等体液进行采集,并分析和传输数据,可以实时获取汗液pH值以及血糖、乳酸盐、钠/钾离子、钙离子、重金属等的含量的信息,这些体液信息对于个体生命体征的实时监测和疾病诊断有着重要的指示性作用.本文介绍了近年来可穿戴式微流控芯片在体液检测和药物递送方面的最新研究进展,以及利用可穿戴式微流控芯片进行生命体征监测的应用案例.本文还简要介绍了利用可穿戴式微流控芯片进行精准药物递送的最新研究动向和应用进展,并对可穿戴式微流控芯片发展过程可能遇到的问题进行了分析,对未来融合发展的前景进行了展望.     

微流控液滴技术及其应用的研究进展

微液滴具有体积小、比表面积大,速度快、通量高,大小均匀、体系封闭,内部稳定等特性,在药物控释、病毒检测、颗粒材料合成、催化剂等领域中均有重要应用.微流控技术的发展为微液滴生成中实现尺寸规格、结构形貌和功能特性等的可控设计和精确操控提供了全新平台.本文概述了微流控液滴技术的基本原理、液滴生成方式及其基本操控,比较分析了微液滴的传统制备法与微流控合成法的异同,介绍了近年来微流控液滴技术在功能材料合成、生物医学和食品加工等领域中的研究新进展,探讨并展望了微流控液滴技术的潜在价值和未来发展方向.     

A review of recent, unconventional applications of ion mobility spectrometry (IMS)

The applications of ion mobility spectrometry (IMS) have grown exponentially beyond its uses for explosive, illicit drug and chemical warfare agent monitoring in recent years. Instrumental developments including new drift tube materials and ionization sources have enabled the manufacturing of more sophisticated and affordable IMS equipment for the advantageous analysis of samples with no pretreatment. The most recent applications of IMS include quality control and cleaning validation procedures in the pharmaceutical industry; determinations of contaminants in food samples; clinical analyses of biological fluids; environmental analyses of contaminants in gaseous, liquid and solid samples; and (bio)process quality control monitoring. Coupling IMS with MSⁿ has enabled the analysis of very complex samples and the extraction of knowledge unavailable from isolated MS measurements, especially in the polymer and petroleomic industries.     

微流控细胞芯片生命分析应用多元化

微流控芯片是现代生命科学研究领域的重要分析工具.结合研究者近年来开展的研究工作和取得的相关进展,本文主要介绍了微流控细胞芯片的功能特征,同时从动物细胞、植物细胞以及微生物细胞三方面系统阐述了微流控芯片生命分析多元化的发展现状,并对其应用前景进行了展望.     

Multiplex bioanalytical methods for food and environmental monitoring

Recent advances in miniaturization of analytical systems and newly emerging technologies offer platforms with greater automation and multiplexing capabilities than traditional biological binding assays. Multiplexed bioanalytical techniques provide control agencies and food industries with new possibilities for improved, more efficient monitoring of food and environmental contaminants. This review deals with recent developments in planar-array and suspension-array technologies, and their applications in detecting pathogens, food allergens and adulterants, toxins, antibiotics and environmental contaminants.     

Intelligent droplet tracking with correlation filters for digital microfluidics

Tracking the movement of droplets in digital microfluidics is essential to improve its control stability and obtain dynamic information for its applications such as point-of-care testing, environment monitoring and chemical synthesis. Herein, an intelligent, accurate and fast droplet tracking method based on machine vision is developed for applications of digital microfluidics. To continuously recognize the transparent droplets in real-time and avoid the interferes from background patterns or inhomogeneous illumination, we introduced the correlation filter tracker, enabling online learning of the multi-features of the droplets in Fourier domain. Results show the proposed droplet tracking method could accurately locate the droplets. We also demonstrated the capacity of the proposed method for estimation of the droplet velocity as faster as 20 mm/s, and its application in online monitoring the Griess reaction for both colorimetric assay of nitrite and study of reaction kinetics.     

Combining nanosurface chemistry and microfluidics for molecular analysis and cell biology

Development of new tools catalyzes progress in biochemical sciences [G.M. Whitesides, E. Ostuni, S. Takayama, X.Y. Jiang, D.E. Ingber, Annual Review of Biomedical Engineering 3 (2001) 335]. Recent advances in micro-/nano-technology have resulted in an explosion of the number of new tools available for biochemical sciences. We have used surface chemistry, nano-structures and microfluidics to create a set of tools applicable for problems ranging from molecular to cellular analysis. These tools will promote the understanding of fundamental problems in cell biology, development and neurobiology, and become useful for real-world applications such as molecular diagnostics, food analysis and environmental monitoring.     

Lipases and their industrial applications

Lipases (triacylglycerol acylhydrolase, EC 3.1.1.3) are part of the family of hydrolases that act on carboxylic ester bonds. The physiologic role of lipases is to hydrolyze triglycerides into diglycerides, monoglycerides, fatty acids, and glycerol. These enzymes are widely found throughout the animal and plant kingdoms, as well as in molds and bacteria. Of all known enzymes, lipases have attracted the most scientific attention. In addition to their natural function of hydrolyzing carboxylic ester bonds, lipases can catalyze esterification, interesterification, and transesterification reactions in nonaqueous media. This versatility makes lipases the enzymes of choice for potential applications in the food, detergent, pharmaceutical, leather, textile, cosmetic, and paper industries. The most significant industrial applications of lipases have been mainly found in the food, detergent, and pharmaceutical sectors. Limitations of the industrial use of these enzymes have mainly been owing to their high production costs, which may be overcome by molecular technologies, enabling the production of these enzymes at high levels and in a virtually purified form.     

Towards online,continuous monitoring for rheometry of complex fluids

This paper presents an overview of the developments that have been made towards the design of an inline rheometer that has the capabilities for monitoring in real time the viscous constitutive parameters of non-Newtonian fluids in a pipe flow. This has potential applications for a wide range of fluids, including hydrocolloid solutions and polymer solutions. This is of relevance to many industries, for example the pharmaceutical, lubrication, food and printing industries. The use of mathematical algorithms for inferring rheological parameters from properties of flow field statistics is explored. Particular focus is given to the development of a flow cell rheometer containing a T-junction geometry with the capacity to induce a range of shear rates in the vicinity of the bend, and a distribution of elongational viscosities along the back-wall. Such features create an information-rich flow field that is beneficial for the development of a rheometer with a fast response time that is suitable for commercial purposes.     

Present and future of expert systems in food analysis

This paper presents an overview of the most relevant contributions in the field of expert system (ES) applications in chemical analysis of foods, along with a critical discussion of future, would-be developments. It illustrates the possibilities offered as well as the fact that quality control laboratories should be aware of the power of artificial intelligence that modern computer technology affords. It is worth noting that the applications described are straightforward with a certain versatility and can, therefore, be implemented for other analytes and/or food samples. Special attention is devoted to the promising distributed knowledge-based systems due to their potential advantages over the existing centralized approaches, as inferred from a recent example of application to the on-line monitoring of some key chemical parameters in the course of a food production process. Short and middle term predictions concerning the potential of ES in food analysis are also made.     

Microfluidic integration for electrochemical biosensor applications

Electrochemical biosensors are particularly suitable for miniaturization and integration in microfluidic devices. Applications include the detection of whole cells, cell components, proteins, and small molecules to address tasks in the fields of diagnostics and food and environmental control. Microfluidic setups range from simple channels for sample transport to channels with integrated sensing electrodes to highly sophisticated platforms with additional elements for sample preparation. The design of the microfluidics depends on both the type of detection and on the application and sample material. This review summarizes recent work on electrochemical biosensors with integrated microfluidics with the focus on developments for real sample applications, particularly those including measurements with real sample media.     

Applications of Modular Microfluidics Technology

Microfluidics has been widely used in the life science, analytical chemistry, environmental science and other fields in the recent years. Traditional microfluidics systems usually use a highly integrated system with multiple components for handling the fluid in the micro/nano scale. The design and fabrication of integrated microfluidics usually require highly sophisticated instruments and operation professionals. With the experience inherited from integrated circuit and micro electro mechanical system, the modular microfluidics system has been experienced a rapid development in recent years. Modular microfluidics system is a combination of a series of individual modules to achieve complicated liquid handling functions. Compared with conventional microfluidics approach, the modular microfluidics method has the potential in significantly reducing the fabrication cost by using the massive production of single chip, besides, it is easy to be operated, and the user can easily assembly the modules to obtain their customized microfluidics system. The concept of modular microfluidics also indicates the future development path for the standardization of microfluidics system and also provides a promising approach for the industrial massive production of microfluidics. However, the study of modular microfluidics is still in an early stage. Although lots of studies have been conducted with varies materials, fabrication methods and interface technologies, issues like modular interface still restricted the further development of microfluidics. In this paper, a comprehensive review for the latest research on the modular microfluidics and applications in biological and medical fields is provided, and the future research trends of modular microfluidics is also discussed.     

Microfluidic platform for on-demand generation of spatially indexed combinatorial droplets

We propose a highly versatile and programmable nanolitre droplet-based platform that accepts an unlimited number of sample plugs from a multi-well plate, performs digitization of these sample plugs into smaller daughter droplets and subsequent synchronization-free, robust injection of multiple reagents into the sample daughter droplets on-demand. This platform combines excellent control of valve-based microfluidics with the high-throughput capability of droplet microfluidics. We demonstrate the functioning of a proof-of-concept device which generates combinatorial mixture droplets from a linear array of sample plugs and four different reagents, using food dyes to mimic samples and reagents. Generation of a one dimensional array of the combinatorial mixture droplets on the device leads to automatic spatial indexing of these droplets, precluding the need to include a barcode in each droplet to identify its contents. We expect this platform to further expand the range of applications of droplet microfluidics to include applications requiring a high degree of multiplexing as well as high throughput analysis of multiple samples.     

Biomolecule immobilization techniques for bioactive paper fabrication

Research into paper-based sensors or functional materials that can perform analytical functions with active recognition capabilities is rapidly expanding, and significant research effort has been made into the design and fabrication of bioactive paper at the biosensor level to detect potential health hazards. A key step in the fabrication of bioactive paper is the design of the experimental and operational procedures for the immobilization of biomolecules such as antibodies, enzymes, phages, cells, proteins, synthetic polymers and DNA aptamers on a suitably prepared paper membrane. The immobilization methods are concisely categorized into physical absorption, bioactive ink entrapment, bioaffinity attachment and covalent chemical bonding immobilization. Each method has individual immobilization characteristics. Although every biomolecule–paper combination has to be optimized before use, the bioactive ink entrapment method is the most commonly used approach owing to its general applicability and biocompatibility. Currently, there are four common applications of bioactive paper: (1) paper-based bioassay or paper-based analytical devices for sample conditioning; (2) counterfeiting and countertempering in the packaging and construction industries; (3) pathogen detection for food and water quality monitoring; and (4) deactivation of pathogenic bacteria using antimicrobial paper. This article reviews and compares the different biomolecule immobilization techniques and discusses current trends. Current, emerging and future applications of bioactive paper are also discussed.     

Applications of capillary electrophoresis to the determination of antibiotics in food and environmental samples

In this paper we review applications of capillary electrophoresis (CE) to the determination of antibiotic residues in food derived from animals and in environmental samples. Although many CE methods have been used to determine antibiotics in the pharmaceutical field (drug quality control or therapeutic monitoring in biological samples), food and environmental applications have been increasing in recent years. Due to the maximum residue limits established by the EU, in Directive 2377/90/EEC, for foodstuffs of animal origin and considering the low levels that can be found in environmental or waste waters or soils, different strategies to increase sensitivity have been developed, including off-line preconcentration, on-line stacking modes to use higher sample volumes, or in-line solid-phase extraction. Also, several detection techniques, such as fluorescence, laser-induced fluorescence, electrochemical detection, or mass spectrometry have been used; the last of these also enables unequivocal identification of the residues, required by Commission Decision 2002/657/EC. All these aspects will be discussed in this paper, in relation to the main groups of antibiotics used in veterinary and human medicine, for which applications in food and environmental samples have been developed by using CE as an efficient alternative to liquid chromatography.     

Chromatographic analysis of banned antibacterial growth promoters in animal feed

The issue of antimicrobial use in animals used as food is of global concern. Antimicrobials are used in animal agriculture to improve health and welfare of animals, meat quality, the economic efficiency of growth and production and public health by decreasing shedding of zoonotic pathogens. However, large quantities are often used without professional supervision. The growth-promotant (now reclassified as zootechnical feed additives) effect of low levels of antibiotics in animal feeds was first described in the late 1940s. Already in 1969 the Swann Committee recommended that use of antibiotics as a supplement in animal feedstuff should be restricted to those with little or no application as therapeutic agents for humans and animals, which would not impair the efficacy of therapeutic antibiotics through the development of resistant strains of organisms. Antimicrobials like avoparcin, ardacin, zinc bacitracin, virginiamycin, tylosin, spriramycin, carbadox and olaquindox were withdrawn within the period 1997-1999. Four others (monensin sodium, salinomycin sodium, avilamycin and flavophospholipol) were still permitted for use as growth promoters in animal feed to animals marketed in the European Union (EU). Since January 2006, they have been banned as well. This review focuses on the analytical methods developed to be an effective tool for monitoring compliance with the ban.     

Electrohydrodynamic processing for the production of zein-based microstructures and nanostructures

Recently, plant-derived proteins have increased in interest and use owing to a combination of interesting properties and industry-wide trends to replace animal-derived proteins. Electrohydrodynamic processing can be used to develop microstructures and nanostructures of plant proteins in a facile manner and, thus, increase their opportunities in the food, pharmaceutical, and biomedical industries. One of the most currently studied and promising plant proteins is zein. This review covers the most studied strategies to produce electrospun and electrosprayed zein-based structures. The most relevant properties, such as size, morphology, and surface area, are discussed as per the potential areas of interest, for instance, in the food, biomedical, and pharmaceutical industries. In addition, applications of other electrospun/electrosprayed plant-derived proteins are also presented, confirming the increasing interest of different industries in alternative proteins which can help promote sustainability.     

原位电离质谱技术在食品质量安全检测中的应用

原位电离质谱技术能够在常压环境下直接分析各种食品样品,无需或仅需极少的食品制备,大大提高了分析效率,已经成为一种重要的食品快速分析方法。本文对原位电离质谱的离子化技术和工作流程进行了介绍,从食品污染物检测、非法添加物筛查、食品真伪鉴别和品质评价等方面出发,综述了该技术在食品质量安全检测中的应用。讨论了其应用于食品分析领域时面临的挑战和未来发展趋势。     

魔芋葡甘聚糖功能材料研究与应用进展

为了更好地开发利用魔芋葡甘聚糖(KGM),本文阐明了KGM独特的结构、优良的理化性质,分析了其结构与性能的关系, 综述了在食品、化工、医药、石油钻探等应用领域中形成的以KGM为基本组成的功能材料研究进展。并对近几年国内外KGM在该领域的研究动向及其应用前景进行了探讨。     

Applying microdroplets as sensors for label-free detection of chemical reactions

Despite its tremendous high-throughput screening capabilities, widespread applications of droplet-based microfluidics are still limited by the poor availability of appropriate analytical assays. Here we report on a novel sensor method that exploits the osmosis-driven change in droplet size as a quantitative and label-free marker for reactions inside the droplets. We present an analysis of the underlying mechanism and apply the method for monitoring metabolic activity at a single-cell level.