水凝胶仿生柔性电子学

水凝胶力学性质与生物组织相似,生物相容性好,在生物电子学领域具有独特的优势.受生物组织——如皮肤、神经、肌肉等启发,发展了具有仿生结构和功能的水凝胶材料.以这种水凝胶材料制作而成的柔性电子器件具有感知温度、压力、应变、电场等外界刺激的功能,可模拟生物组织的传感能力,在仿生电子皮肤,人工肌肉,人工神经等领域具有重要的应用...     

Advances in nitric oxide-releasing hydrogels for biomedical applications

Hydrogels provide a plethora of advantages to biomedical treatments due to their highly hydrophilic nature and tissue-like mechanical properties. Additionally, the numerous and widespread endogenous roles of nitric oxide have led to an eruption in research developing biomimetic solutions to the many challenges the biomedical world faces. Though many design factors and fabrication details must be considered, utilizing hydrogels as nitric oxide delivery vehicles provides promising materials in several applications. Such applications include cardiovascular therapy, vasodilation and angiogenesis, antimicrobial treatments, wound dressings, and stem cell research. Herein, a recent update on the progress of NO-releasing hydrogels is presented in depth. In addition, considerations for the design and fabrication of hydrogels and specific biomedical applications of nitric oxide-releasing hydrogels are discussed.     

Enzyme association with lipidic Langmuir-Blodgett films: interests and applications in nanobioscience

This review presents the recent advances in the achievement of organized proteo-lipidic nanostructures based on Langmuir-Blodgett technology and their potential applications in the nanobioscience area. By using the self-assembled properties of amphiphilic biomolecules at the air-water interface, the Langmuir-Blodgett (LB) technique offers the possibility to prepare ultrathin layers suitable for biomolecule immobilization at the molecular level. This review will provide a general overview of the enzyme association with preformed Langmuir-Blodgett films in connection with their potential applications in biosensing device developments, and then introduce the design of a new functionalised biomimetic nanostructure with oriented recognition site. The potential applications of such an organized proteo-lipidic nanostructure for biocatalysis investigations of an immobilised enzyme in a biomimetic situation and for the development of bioelectronic devices are finally discussed.     

仿生干湿摩擦黏附器件的研究进展

生物在自然界的演化过程中进化出了许多独特的干湿摩擦、黏附器官来适应其生存环境.研究人员通过对自然界中典型摩擦与黏附现象的研究、认识和总结,提出了相应的仿生界面摩擦、黏附理论与模型,用于指导人工合成型智能摩擦黏附材料与器件.目前,仿生摩擦、黏附材料体系与器件的设计策略主要以表面微结构、界面物理化学相互作用以及机械形变为基...     

Multifunctional cold spray coatings for biological and biomedical applications: A review

A variety of coating techniques are available for medical devices to be tailored with surface properties aimed at optimizing their performance in biological environments. Cold spray, as a member of the thermal spray family, is now being exploited to efficiently deposit micro- to nanometer sized metallic or non-metallic particles on surgical implants, medical devices and surfaces in the healthcare environment to create functional coatings. Cold spray has attracted attention in the context of biomedical applications due to the fact that multiple materials can be combined easily at the surface of these devices, and that oxygen-sensitive and heat-sensitive organic molecules, including bioactive compounds, can be incorporated in these coatings due to the relatively low temperatures used in the process. The ability to maintain material and chemical properties and the ability to create functional coatings make the cold spray process particularly suitable for applications in the MedTech industry sector.This review explores the fabrication of cold spray coatings including the types of materials that have been used for biomedical purposes, provides a detailed analysis of the factors affecting cold spray coating performance, and gives an overview over the most recent developments related to the technology. Cold spray coatings that have been used until this point in time in biomedical applications can be broadly classified as biocompatible coatings, anti-infective coatings, anti-corrosive coatings, and wear-resistant coatings. In addition, this review discusses how these applications can be broadened, for example by providing antiviral effect against coronavirus (COVID-19). While we highlight examples for multifunctional cold spray coatings, we also explore the current challenges and opportunities for cold spray coatings in the biomedical field and predict likely future developments.     

Recent Advances in Polyurethane/POSS Hybrids for Biomedical Applications

Advanced organic-inorganic materials-composites, nanocomposites, and hybrids with various compositions offer unique properties required for biomedical applications. One of the most promising inorganic (nano)additives are polyhedral oligomeric silsesquioxanes (POSS); their biocompatibility, non-toxicity, and phase separation ability that modifies the material porosity are fundamental properties required in modern biomedical applications. When incorporated, chemically or physically, into polyurethane matrices, they substantially change polymer properties, including mechanical properties, surface characteristics, and bioactivity. Hence, this review is dedicated to POSS-PU composites that have recently been developed for applications in the biomedical field. First, different modes of POSS incorporation into PU structure have been presented, then recent developments of PU/POSS hybrids as bio-active composites for scaffolds, cardiovascular stents, valves, and membranes, as well as in bio-imaging and cancer treatment, have been described. Finally, characterization and methods of modification routes of polyurethane-based materials with silsesquioxanes were presented.     

Equivalent dynamic thermoviscoelastic modeling of ionic polymers

Ionic polymers have attracted considerable attention due to their interesting sensing and actuating behavior which make them a proper choice for use in a wide range of applications including biomimetic robots and biomedical devices. The complicated electro‐chemo‐mechanical dynamics of ionic polymer actuators is a drawback for their applications in functional devices. Therefore, establishing a mathematical model which could effectively predict the actuators' dynamic behavior is of great interest. In this paper, a mathematical model, named equivalent dynamic thermoviscoelastic (EDT) model, based on thermal analogy and beam theory is proposed for dynamic analysis of bending‐type ionic polymer actuators. Then, the developed model is extended for analyzing the performance of the actuator in finite element software. The finite element analysis of the actuator enables consideration of material and geometric nonlinearities and facilitates modeling of functional devices based on the ionic polymer actuators. The proposed modeling approach is validated using experimental data. Copyright © 2015 John Wiley & Sons, Ltd.     

Advances in Biohybridized Planar Polymer Membranes and Membrane-Like Matrices

The past few decades have seen increasing growth in the field of biomimetic membranes and thus also a rapid expansion of their biomedical and technological applications. Versatility, stability and scalability have moved biohybrid polymer membranes into the limelight. This review focuses on planar, soft polymer membranes and polymer-based matrices and their role as a host for different types of biomolecules. Because biomimetic polymer platforms present an extensive, ever-growing field, we limit ourselves mostly to the discussion of producing planar polymer membranes on solid supports that lend themselves to functionalization by biomolecules. We present an overview of the major highlights and challenges associated with the biohybridization of such polymer platforms. In particular, we elaborate on procedures developed to maintain optimal peptide and membrane protein performance in a customized polymer membrane or membrane-like environment. Finally, we discuss a number of applications of such biohybridized polymer platforms and contemplate future developments to further exploit their potential.     

Bioorganic applications of semisynthetic DNA-protein conjugates

Semisynthetic DNA-protein conjugates are versatile molecular tools useful, for instance, in the self-assembly of high-affinity reagents for immunological detection assays, the fabrication of highly functionalized laterally microstructured biochips, and the biomimetic "bottom-up" synthesis of nanostructured supramolecular devices. This concept paper summarizes the current state-of-the-art concerning the synthesis, characterization, and applications of such hybrid molecules, and also draws perspectives on future developments.     

氢键作用驱动原花青素构筑水基抗菌黏合剂北大核心CSCD

水下黏合剂在生物医学和工程应用领域的需求越来越大。然而,目前报道的大多数水下黏合剂的制备方法中通常需要复杂的化学偶联或修饰,以及昂贵的构筑基元。本文利用低成本的葡萄籽提取物原花青素(PA)和商业化的聚乙二醇寡聚物(PEG)为构筑基元,发展了一种简单且经济的水下黏合剂的构筑策略,实现了在氢键作用下诱导仿生黏合剂生成。此黏合剂既可以在水上又可以在水下黏附不同材质的基底,且可重复使用。此外,易于制备的PA/PEG黏合剂也具有良好的抗菌活性和生物相容性。由于PA/PEG黏合剂具有制备简单、广谱黏附性、可循环使用和抗菌性等优点,将在医疗器械和制药应用中得到广泛应用。     

A review of dielectrophoretic separation and classification of non-biological particles

Dielectrophoresis (DEP) is a selective electrokinetic particle manipulation technology that is applied for almost 100 years and currently finds most applications in biomedical research using microfluidic devices operating at moderate to low throughput. This paper reviews DEP separators capable of high-throughput operation and research addressing separation and analysis of non-biological particle systems. Apart from discussing particle polarization mechanisms, this review summarizes the early applications of DEP for dielectric sorting of minerals and lists contemporary applications in solid/liquid, liquid/liquid, and solid/air separation, for example, DEP filtration or airborne fiber length classification; the review also summarizes developments in DEP fouling suppression, gives a brief overview of electrocoalescence and addresses current problems in high-throughput DEP separation. We aim to provide inspiration for DEP application schemes outside of the biomedical sector, for example, for the recovery of precious metal from scrap or for extraction of metal from low-grade ore.     

Hybrid microgels with reversibly changeable multiple brilliant color

We report reversibly color changeable hybrid microgels that tune multiple brilliant colors due to interparticle interactions of SPR using several structured nanoparticles. The interparticle interactions were brought out using the thermosensitive swelling/deswelling property of microgel. We employ N-isopropylacrylamide (NIPAM) and glycidyl methacrylate (GMA) copolymerized microgels (NG microgels) as templates for in situ synthesis of Au nanoparticles. The seed Au nanoparticles could be stably grown by successive reduction of Au and Ag in the microgels. Interestingly, the hybrid microgels were able to exhibit multiple brilliant colors by attaching Au/Ag multiple core/shell bimetallic nanoparticles in the microgels, and the color change reversibility of each hybrid microgel was accomplished by adjusting the nanoparticles' sizes. Obtained microgels shown in this study will find important applications such as in biomedical and electronic devices.     

仿生高分子的研究进展

本文介绍了近年来结构仿生高分子材料和功能仿生高分子材料方面的研究进展,介绍了生物材料的多级有序结构、智能水凝胶、仿荷叶表面、高分子在细胞培养和生物矿化等方面的研究结果,探讨了这一领域的可能发展方向.     

On the cyclic deformation behavior,fracture properties and cytotoxicity of silicone-based elastomers for biomedical applications

This paper provides results from a comprehensive experimental characterization on five silicone-based elastomers used as substrates for mechanobiological studies or in soft biomedical implants. A previous paper was recently published which focused on the large strain deformation behavior of these materials. This second part analyzes their reliability for biomedical applications in terms of changes of deformation behavior with the history of loading (long term cyclic behavior), ability to resist loads in the presence of defects (fracture properties), and cytotoxicity. For the latter, all materials are confirmed to be non-toxic which is a prerequisite for their use in mechanobiological studies or as part of implants and biomedical devices. The response in long term uniaxial tests over 220′000 cycles was characterized and the results indicate general stability of the mechanical response with, for some conditions, softening mechanisms active mainly in the initial phase of the test (50′000 cycles). A critical aspect of elastomer performance and their suitability for application in biomedical devices concerns their fracture properties. The tearing energy varies in a range from brittle (with approximately 80 J/m² for PDMS Sylgard 184) to tough (with approximately 900 J/m² for SMI G/G 0.020).     

Biomimetic membranes for sensor and separation applications

Biological membranes constitute the set of membranes defining boundaries and organelles in living cells—the structural and functional building blocks of all known living organisms. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized and highly efficient transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create membrane-based sensor and/or separation devices? In the development of biomimetic sensor/separation technology, both channels (ion and water channels) and carriers (transporters) are important. Generally, each class of transport proteins conducts specific molecular species in and out of the cell while preventing the passage of others, a property critical for the overall conservation of the cells internal pH and salt concentration. Both ion and water channels are highly efficient membrane pore proteins capable of transporting solutes at very high rates, up to 10⁹ molecules per second. Carrier proteins generally have a lower turnover but are capable of transport against gradients. For both classes of proteins, their unique flux-properties make them interesting as candidates in biomimetic sensor/separation devices. An ideal sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to water, electrolytes, and non-electrolytes. The feasibility of a biomimetic device thus depends on the relative transport contribution from both protein and biomimetic support matrix. Also the stability of the incorporated protein must be addressed and the protein-biomimetic matrix must be encapsulated in order to protect it and make it sufficiently stable in a final application. Here I will review and discuss these challenges and how they are met in some current developments of biomimetic sensor/separation devices.     

Spintronic platforms for biomedical applications

Since the fundamental discovery of the giant magnetoresistance many spintronic devices have been developed and implemented in our daily life (e.g. information storage and automotive industry). Lately, advances in the sensors technology (higher sensitivity, smaller size) have potentiated other applications, namely in the biological area, leading to the emergence of novel biomedical platforms. In particular the investigation of spintronics and its application to the development of magnetoresistive (MR) biomolecular and biomedical platforms are giving rise to a new class of biomedical diagnostic devices, suitable for bench top bioassays as well as point-of-care and point-of-use devices. Herein, integrated spintronic biochip platforms for diagnostic and cytometric applications, hybrid systems incorporating magnetoresistive sensors applied to neuroelectronic studies and biomedical imaging, namely magneto-encephalography and magneto-cardiography, are reviewed. Also lab-on-a-chip MR-based platforms to perform biological studies at the single molecule level are discussed. Overall the potential and main characteristics of such MR-based biomedical devices, comparing to the existing technologies while giving particular examples of targeted applications, are addressed.     

Centrifugally-driven sample extraction, preconcentration and purification in microfluidic compact discs

Centrifugally-driven microfluidic compact discs (μ-CDs) have attracted significant interest within the analytical science community in the past decade, with the primary focus on the potential of such platforms for performing parallel and/or multiplex biological assays and further application in biomedical diagnostics. More recently, μ-CD-based devices were also applied to environmental analysis as platforms for multi-sample extraction and transportation, prior to off-disc analysis in the laboratory. This review critically summarizes recent developments in μ-CD platforms for sample extraction, preconcentration, fractionation and purification in bioanalytical and environmental applications. We also summarize the common methods employed in the fabrication of μ-CD platforms. Further, we discuss preparation of stationary phases in microfluidic channels embedded in μ-CDs, as applications of μ-CDs in sample extraction are generally based on enclosed series of extraction phases and microcolumns.     

UV-Vis-NIR Light-deformable Shape-memory Polyurethane Doped with Liquid-crystal Mixture and GO towards Biomimetic Applications

Nature has been inspiring material researchers to fabricate biomimetic functional devices for various applications, and shape-memory polymer materials(SMPMs) have received tremendous attention since the promising intelligent materials possess more advantages over others for the fabrication of biomimetic functional devices. As is well-known, SMPMs can be stimulated by heat, electricity, magnetism, pH, solvent and light. From the viewpoint of practical applications, ultraviolet(UV)-visible(Vis)-near infrared(NIR) light-responsive SMPMs are undoubtedly more advantageous. However, up to now, UV-Vis-NIR light-deformable SMPMs by combining photothermal and photochemical effects are still rarely reported. Here we designed a UV-Vis-NIR light-deformable SMP composite film via incorporating a liquid crystal(LC) mixture and graphene oxide(GO) into a shape-memory polyurethane matrix. The elongated composite films exhibited interesting photomechanical bending deformations with different light-triggered mechanisms,(1) photochemically induced LC phase transition upon UV exposure,(2) photochemically and photothermally induced LC phase transition upon visible-light irradiation,(3) photothermally triggered LC phase transition and partial stress relaxation upon low-intensity NIR exposure. All the deformed objects could recover to their original shapes by high-intensity NIR irradiation.Moreover, the biomimetic circadian rhythms of acacia leaves and the biomimetic bending/spreading of fingers were successfully achieved, which could blaze a way in the field of biomimetic functional devices due to the excellent light-deformable and shape-memory properties of the SMP composite films.