Biomedical and biological mass spectrometry.

This review focuses on biological and biomedical mass spectrometry, and covers a selection of publications in this area included in the MEDLINE database for the period 1987-2001. Over the last 15 years, biological and biomedical mass spectrometry has progressed out of all recognition. The development of soft ionization methods, such as electrospray ionization and matrix-assisted laser desorption ionization, has mainly contributed to the remarkable progress, because they can easily produce gas-phase ions of large, polar, and thermally labile biomolecules, such as proteins, peptides, nucleic acids and others. The innovations of ionization methods have led to remarkable progress in mass spectrometric technology and in biochemistry, biotechnology and molecular biology research. In addition, mass spectrometry is one of the powerful and effective technologies for drug discovery and development. It is applicable to studies on structural determination, drug metabolism, including pharmacokinetics and toxicokinetics, and de novo drug discovery by applying post-genomic approarches. In the present review, the innovative soft ionization methods are first discussed along with their features. Also, the characteristics of the mass spectrometers which are active in the biological and biomedical research fields are also described. In addition, examples of the applications of biological and biomedical mass spectrometry are provided.     

A guide to design the trajectory of active particles: From fundamentals to applications

Active particles convert external energy into motility, displaying a variety of dynamical features. Recent progress in the field has marked a shift in focus from understanding the origin and sources of active motion to controlling the dynamics and trajectory of individual microswimmers. This review explores the advancements made in a two-fold perspective—the role of particle design and that of external factors. Our main goal is to highlight the guiding principles, which determine active particle trajectory. These include, on the one hand, the role of the morphology of active particles and their assemblies in driving translation, rotation, and corresponding coupling between the two. On the other hand, the effect of environmental parameters such as the presence of physicochemical heterogeneities including interfaces, suspended obstacles, and boundaries on the modality and trajectory of active colloids. We discuss the potential of using active particles in biomedical and environmental applications through recent examples.     

软机器人的运动行为研究进展

软机器人的出现不仅弥补了传统机器人的缺点,并逐渐成为机器人领域的热点和前沿之一,近年来该领域研究进展十分迅速。本文总结了典型软机器人的运动行为的研究进展,介绍了软机器人按材质类型的分类(包括液晶软机器人、生物分子软机器人、PDMS软机器人、液体软机器人和自振荡凝胶软机器人)及其功能和潜在应用,讨论了当前不同类别软机器人运动的特点和存在的问题,在此基础上展望了软机器人领域面临的机遇、挑战和未来发展方向。     

Complex three-dimensional microparticles from microfluidic lithography

Complex 3D microparticle, as an emerging and attractive field, has attracted more and more attention due to its versatile morphologies and broad range of applications. In this review, we provide an overall recent progress in 3D microparticles fabricated by microfluidic lithography. This review will focus on the synthesis mechanisms, synthesis process, the resultant 3D microparticles, and their applications. Finally, we will look into the future trends in complex 3D microparticles. This review will be beneficial for researchers in numerous fields, including functional materials, sensors, encryption, and biomedical engineering.     

Biohybrid bacterial microswimmers with metal-organic framework exoskeletons enable cytoprotection and active drug delivery in a harsh environment

The inspiring idea of using motile bacteria as bioengines to create biohybrid microswimmers has been realized by integrating functionalized cargos with bacteria recently. However, existing pernicious factors in ambient conditions, such as enzymes, may attack bacterial microsystems when they are executing tasks. Here, a versatile bacterial microswimmer system with cytoprotective metal-organic framework (MOF) exoskeletons is reported, capable of protecting the bioengine from enzyme degradation. Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (NPs) are fully coated on the surface of motile bacteria (Escherichia coli MG1655) through tannic acid (TA) complexation. The ZIF-8 wrapping is demonstrated with negligible influence on bacterial motility under optimized conditions. Moreover, ZIF-8@E. coli microswimmers still maintain their shapes and motion performance in the presence of lysozyme, verifying the effective preservation of formed ZIF-8 exoskeletons on the bacterial surface. Coupling with the drug loading capacity of ZIF-8, Doxorubicin (DOX)-loaded ZIF-8@E. coli microsystems retain their effective propulsion after being treated with lysozyme, enabling the accelerated crossing through the Transwell membrane and improving anticancer efficacy compared with passive drugs. The fabricated bacterial microswimmers were also verified with chemotactic motion and prolonged retention time in the mouse bladder, holding great potential to design an active medical platform with improved therapeutic efficacy for targeted disease treatment, such as bladder cancer. Combining bacteria with MOFs generates multifunctional biohybrid microswimmers with capabilities of cytoprotection and active drug delivery. Such design facilitates the development of active biosystems to apply in harsh environments and meets rigorous requirements in clinical biomedical applications.     

Recent Progress in Shape Memory Polymers for Biomedical Applications

Shape memory polymers (SMPs) as one type of the most important smart materials have attracted increasing attention due to their promising application in the field of biomedicine,textiles,aerospace et al.Following a brief intoduction of the conception and classification of SMPs,this review is focused on the progress of shape memory polymers for biomedical applications.The progress includes the early researches based on thermo-induced SMPs,the improvement of the stimulus,the development of shape recovery ways and the expansion of the applications in biomedical field.In addition,future perspectives of SMPs in the field of biomedicine are also discussed.     

Advancement in the Biomedical Applications of the (Nano)gel Structures Based on Particular Polysaccharides

(Nano)gels from macromolecular compounds—natural, synthetic, or a combination thereof, suitable crosslinkers—and conferred characteristics—such as degradability, size, charge, amphiphilicity, responsiveness, and softness—are capable of responding to the challenges imposed by bioengineering applications. Polysaccharide‐based gels have received particular attention in this field. This review addresses recent advancement in the use of (nano)gel structures prepared only from compounds based on gellan gum, heparin, chondroitin sulfate, carrageenan, guar gum, galactose, or agarose, which represent an important part of the special class of natural polymers, the polysaccharides. Also, future trends are taken into discussion regarding the (nano)gels' use in biomedical applications such as biomimetics, biosensors, artificial muscles, and chemical separations in relation with their ability to be used as a vehicle for various biomolecules due to their physicochemical properties, biocompatibility, and biodegradability.     

Recent progress in polymer hydrogel bioadhesives

Adhesive hydrogels have broad applications in tissue adhesives, hemostatic agents, and biomedical sensors. Various bio-inspired glues and synthetic adhesives are clinically used as conventional hemostatic agents and auxiliary tools for wound closure. Medical adhesives are needed to effectively and quickly control bleeding, thereby reducing the risk of complications caused by severe blood loss. Medical sensors need to have excellent skin compliance, mechanical properties, sensitivity, and biological safety. This review focuses on recent progress in adhesive hydrogel systems, their structures, adhesion mechanisms, construction strategies, and emerging applications in the biomedical field.     

Construction of Smart Stimuli-Responsive DNA Nanostructures for Biomedical Applications

DNA nanostructures have recently attracted increasing interest in biological and biomedical applications by virtue of their unique properties, such as structural programmability, multi-functionality, stimuli-responsive behaviors, and excellent biocompatibility. In particular, the intelligent responsiveness of smart DNA nanostructures to specific stimuli has facilitated their extensive development in the field of high-performance biosensing and controllable drug delivery. This minireview begins with different self-assembly strategies for the construction of various DNA nanostructures, followed by the introduction of a variety of stimuli-responsive functional DNA nanostructures for assembling metastable soft materials and for facilitating amplified biosensing. The recent achievements of smart DNA nanostructures for controllable drug delivery are highlighted. Finally, the current challenges and possible developments of this promising research are discussed in the fields of intelligent nanomedicine.     

Stimulus‐Responsive Metal–Organic Frameworks

Materials that can recognize the changes in their local environment and respond by altering their inherent physical and/or chemical properties are strong candidates for future “smart” technology materials. Metal–organic frameworks (MOFs) have attracted a great deal of attention in recent years owing to their designable architecture, host–guest chemistry, and softness as porous materials. Despite this fact, studies on the tuning of the properties of MOFs by external stimuli are still rare. This review highlights the recent developments in the field of stimulus‐responsive MOFs or so‐called smart MOFs. In particular, the various stimuli used and the utility of stimulus‐responsive smart MOFs for various applications such as gas storage and separation, sensing, clean energy, catalysis, molecular motors, and biomedical applications are highlighted by using representative examples. Future directions in the developments of stimulus‐responsive smart MOFs and their applications are proposed from a personal perspective.     

手性纳米材料: 生物成像、 生物传感与治疗

手性无机纳米结构不仅形貌和结构可调控、 易于表面功能化修饰, 而且光学性质独特, 在生物领域的应用上展现了很大的优异性. 本文综述了近年来手性纳米技术在生物医学领域的研究进展, 重点介绍了手性金属和手性半导体纳米结构的合成策略、 圆二色效应、 光手性机制及在生物成像、 生物传感、 肿瘤以及神经退行性疾病等医学领域的应用. 手性纳米材料的研究丰富了生物化学的纳米技术手段, 促进了肿瘤等重大疾病诊断与治疗技术的进步, 推动了手性在生命科学中的发展, 鼓励了研究者对这一新兴领域的持续探索与挑战.     

Mechanical characterization of soft microparticles prepared by droplet microfluidics

Droplet microfluidics is one of the most promising approaches that allows preparation of microparticles with tailored structure and composition. Various functional microparticles have been developed using microfluidics, where their controlled structure shows high potential for a wide range of applications. Among these, soft polymeric microparticles which exhibit low elastic modulus compared to ceramics and metals are extensively investigated in biomedical applications due to their biocompatibility, high surface-to-volume ratio, as well as soft and deformable nature. As the mechanical properties of soft microparticles play important role in determining how they function in each application, it is essential to adequately characterize them for the optimal design of functional microparticles. In this review, we mainly discuss the mechanical characterization methods of soft microparticles and their elastic property. A brief overview of the droplet microfluidics-assisted fabrication of microparticles is also provided before discussing the mechanical characterization techniques. We then describe the general characterization methods and models employed to determine the elastic properties of microparticles. In addition, we discuss the relationship between the physical parameters (size, composition, and structure) and the elastic properties of the microparticles, followed by the role of elastic properties in various applications including microcarrier, bioink, and self-healing to name a few.     

A review on electrospun polymeric nanofibers: Production parameters and potential applications

This review deals with electrospun nanofibers and their applications in several fields. Nanofibers have mainly been produced via electrospinning technique due to the simple, cost-effective, and versatile setup. Electrospinning is defined as a process, which produces fibers from its polymer solutions under exposure of high electric field voltage. The technique needs optimization of several parameters such solution, processing and ambient parameters to refine nanofiber morphology, diameter and porosity. The basic technique has been modified to produce composite fibers and to increase production capacity. Nanofiber characterization methods are summarized with examples. The relation between electrospinning and electrospraying is discussed. Nanofibers have the ability to form highly porous mesh with large surface to volume ratio enhancing its performance for various applications such as water filtration, tissue engineering scaffold, wounds, fiber composites, drug release and protective clothes. Single nanofibers could potentially be used as soft microrobots for drug delivery. Finally, results from modeling and simulations are illustrated.     

Biosensors based on molecular beacons

A fundamental molecular beacon (MB) consists of a special short nucleic acid strand with a fluorophore-quencher pair attached to its ends. It provides a unique framework that is susceptible to conformational transitions between a hairpin (closed) conformation and an extended (open) conformation. These two conformations are readily discernible because of their differing fluorescence emission characteristics. The broad applicability of the robust MB sensing platform has attracted widespread interest, resulting in extensive research studies ranging from theoretical and bioanalytical chemistry to molecular biology and biomedical applications. In this paper, the principles of MB design and the modes and mechanisms of MB operation are reviewed, including MB modifications based on the utilisation of a thymidine-thymidine mismatch in hybridised MB stem, aptamers, peptides and locked nucleic acid strands in an MB loop, as well as plasmonic quenchers, quantum dots and interactions with graphene and graphene oxide. Specific applications of MBs in the analysis of enzymes, DNA mutation, phosphorylation, methylation and ligation, followed by the detection of pathogens and applications in cancer and other disease diagnostics and therapeutics are also reviewed. Molecular beacon-based sensing platforms are expanding rapidly and offer a promising bioanalytical tool for inexpensive and reliable analysis for research and field diagnostics.     

Microrobots in Brewery: Dual Magnetic/Light-Powered Hybrid Microrobots for Preventing Microbial Contamination in Beer

Yeasts play a key role in the production of alcoholic beverages by fermentation processes. However, because of their continuous growth, they commonly cause spoilage of the final product. Herein, we introduce dual magnetic/light-responsive self-propelled microrobots that can actively move in a beer sample and capture yeast cells. The presence of magnetic nanoparticles on the surface of the microrobots enables their magnetic actuation under fuel-free conditions. In addition, their photoactivity under visible-light irradiation leads to an overall enhancement of their swimming and yeast removal capabilities. It was found that after the application of the microrobots into a real unfiltered beer sample, these micromachines were able to remove almost 100 % of residual yeasts. In addition, these microrobots could also be added at the initial step of the fermentation process without altering the final beer properties, such as alcohol level, color, and pH. This work demonstrates the potential of using externally actuated microrobots as an innovative and low-cost solution for avoiding yeast spoilage in complex liquid environments, such as alcoholic beverages. Therefore, these autonomous self-propelled microrobots open new avenues for future applications in the food industry.     

Fuel‐Free Micro‐/Nanomotors as Intelligent Therapeutic Agents

There are many efficient biological motors in Nature that perform complex functions by converting chemical energy into mechanical motion. Inspired by this, the development of their synthetic counterparts has aroused tremendous research interest in the past decade. Among these man‐made motor systems, the fuel‐free (or light, magnet, ultrasound, or electric field driven) motors are advantageous in terms of controllability, lifespan, and biocompatibility concerning bioapplications, when compared with their chemically powered counterparts. Therefore, this review will highlight the latest biomedical applications in the versatile field of externally propelled micro‐/nanomotors, as well as elucidating their driving mechanisms. A perspective into the future of the micro‐/nanomotors field and a discussion of the challenges we need to face along the road towards practical clinical translation of external‐field‐propelled micro‐/nanomotors will be provided.     

Laser ablation ICP-MS for quantitative biomedical applications

LA-ICP-MS allows precise, relatively fast, and spatially resolved measurements of elements and isotope ratios at trace and ultratrace concentration levels with minimal sample preparation. Over the past few years this technique has undergone rapid development, and it has been increasingly applied in many different fields, including biological and medical research. The analysis of essential, toxic, and therapeutic metals, metalloids, and nonmetals in biomedical tissues is a key task in the life sciences today, and LA-ICP-MS has proven to be an excellent complement to the organic MS techniques that are much more commonly employed in the biomedical field. In order to provide an appraisal of the fast progress that is occurring in this field, this review critically describes new developments for LA-ICP-MS as well as the most important applications of LA-ICP-MS, with particular emphasis placed on the quantitative imaging of elements in biological tissues, the analysis of heteroatom-tagged proteins after their separation and purification by gel electrophoresis, and the analysis of proteins that do not naturally have ICP-MS-detectable elements in their structures, thus necessitating the use of labelling strategies.     

表面抗菌功能涂层的构建及在生物医用材料中的应用研究

近年来,生物医用材料在使用过程中产生的医源性感染问题层出不穷,对人们健康和生命造成严重威胁.表面抗菌涂层构建是解决该类医源性感染问题最有效的策略之一.目前,按照作用机制和功能不同将表面抗菌涂层分为接触式抗菌涂层、抗黏附抑菌涂层、抗黏附杀菌涂层以及智能抗菌涂层.表面抗菌涂层的构建不仅赋予了生物医用材料抗菌性能,有效解决了上述医源性感染问题,还可以提高材料的生物相容性,赋予其抗黏附、抗氧化、生物识别、传感等功能.本文旨在对目前表面抗菌涂层的种类、构建方法以及其在生物医用材料领域中的应用做一全面论述,为进一步开发高性能表面抗菌涂层并扩展其应用提供新思路.     

Photomechanical polymer hydrogels based on molecular photoswitches

As intelligent materials responsive to light, photomechanical hydrogels not only possess high-water content, excellent softness and biocompatibility, but also can accomplish various mechanical motions upon spatiotemporal stimulation of external light, which exhibit great potential in biomedical and underwater bionic fields. Molecular photoswitches have been used broadly in preparation of photomechanical hydrogels owing to their high photosensitivity and reversible molecular structure transformations induced by light. Herein, the current progress of photomechanical hydrogels based on typical molecular photoswitches such as spiropyran, azobenzene, and hexaarylbiimidazole (HABI) are introduced. Especially, as a promising building unit for photomechanical hydrogels, HABI has been highlighted due to the unique molecular structures and reversible photoswitching capability. HABI-derived polymer hydrogels demonstrate flexible mechanical behaviors upon localized light irradiation. The characteristics and challenges of photomechanical hydrogels based on molecular photoswitches are also prospected.     

Layer-by-layer assembly of microcapsules and their biomedical applications

Nanoengineered multifunctional capsules with tailored structures and properties are of particular interest due to their multifunctions and potential applications as new colloidal structures in diverse fields. Among the available fabrication methods, the layer-by-layer (LbL) assembly of multilayer films onto colloidal particles followed by selective template removal has attracted extensive attention due to its advantages of precise control over the size, shape, composition, wall thickness and functions of the obtained capsules. The past decade has witnessed a rapid increase of research concerning the new fabrication strategies, functionalization and applications of this kind of capsules, particularly in the biomedical fields such as drug delivery, biosensors and bioreactors. In this critical review, the very recent progress of the multilayer capsules is summarized. First, the advances in assembly of capsules by the LbL technique are introduced with focus on tailoring the properties of hydrogen-bonded multilayer capsules by cross-linking, and fabrication of capsules based on covalent bonding and bio-specific interactions. Then the fabrication strategies which can speed up capsule fabrication are reviewed. In the following sections, the multi-compartmental capsules and the capsules that can transform their shape under stimulus are presented. Finally, the biomedical applications of multilayer capsules with particular emphasis on drug carriers, biosensors and bioreactors are described (306 references).