Self-assembled Supramolecular Artificial Transmembrane Ion Channels: Recent Progress and Application

Natural protein channels have evolved with fantastic spatial structures, which play pivotal physiological functions in all living systems. Learning from nature, chemical scientists have developed a myriad of artificial transmembrane ion channels by using various chemical strategies, among which the non-covalent supramolecular ion channels exhibit remarkable advantages over other forms(e.g., single-molecule ion channel), which exhibited facile preparation methods, easier structural modification and functionalization. In this review, we have systematically summarized the recent progress of supramolecular self-assembled artificial transmembrane ion channels, which were classified by different self-assembly mechanisms, such as hydrogen bonds, π-π interactions, etc. Detailed preparation process and self-assembly strategies of the supramolecular ion channels have been described. Moreover, potential biomedical applications of the supramolecular ion channels have also been carefully discussed in this review. Finally, future opportunities and challenges facing this field were also elaborately discussed. It is anticipated that this review could provide a panoramic sketch and future directions towards the construction of novel artificial ion channels with novel functions and biomedical applications.     

Strong Protein Adhesives through Lanthanide-enhanced Structure Folding and Stack Density

Generating strong adhesion by engineered proteins has the potential for high technical applications. Current studies of adhesive proteins are primarily limited to marine organisms, e.g., mussel adhesive proteins. Here, we present a modular engineering strategy to generate a type of exotic protein adhesives with super strong adhesion behaviors. In the protein complexes, the lanmodulin (LanM) underwent α-helical conformational transition induced by lanthanides, thereby enhancing the stacking density and molecular interactions of adhesive protein. The resulting adhesives exhibited outstanding lap-shear strength of ≈31.7 MPa, surpassing many supramolecular and polymer adhesives. The extreme temperature (−196 to 200 °C) resistance capacity and underwater adhesion performance can significantly broaden their practical application scenarios. Ex vivo and in vivo experiments further demonstrated the persistent adhesion performance for surgical sealing and healing applications.     

面向近红外脑功能成像的光学自导引漫射光断层成像方法

为降低近红外脑功能漫射光断层成像(DOT)固有的逆问题病态性,并避免多模态方法的图像配准等问题,提出了基于光学自导引提供先验功能信息的脑功能DOT方法(OT-DOT),并发展了图像重构方法.模拟验证表明:上皮厚度(TLT)已知时,OT-DOT获得的重构量化度(QR)约为传统DOT的4.2倍;当TLT的估计误差小于±10%时,OT-DOT重构的QR值可达92%以上,远远优于传统DOT;噪声鲁棒性测试表明,OT-DOT与传统DOT的噪声鲁棒性相近.利用连续光DOT测量系统的仿体实验重构结果表明,所发展的OT-DOT算法获得的重构结果优于传统DOT算法.     

石墨烯的生物医用研究进展

石墨烯及其衍生物在生物医学领域的应用愈来愈受到人们的关注,其研究领域已经涉及到生物传感、疾病诊断、药物和基因载体、抗菌和抗病毒、生物成像以及肿瘤的光热和光动力治疗、组织工程等。研究的热点也多集中在石墨烯的生物安全性和生物降解性及其衍生物的合成与制备,但至今仍有一些问题尚未解决。本文主要是介绍近几年有关石墨烯生物相容性及其在生物医学领域的研究进展,并对其发展前景进行了展望。     

Strengths and weaknesses of in-tube solid-phase microextraction: A scoping review

In-tube solid-phase microextraction (in-tube SPME or IT-SPME) is a sample preparation technique which has demonstrated over time its ability to couple with liquid chromatography (LC), as well as its advantages as a miniaturized technique. However, the in-tube SPME perspectives in the forthcoming years depend on solutions that can be brought to the environmental, industrial, food and biomedical analysis. The purpose of this scoping review is to examine the strengths and weaknesses of this technique during the period 2009 to 2015 in order to identify research gaps that should be addressed in the future, as well as the tendencies that are meant to strengthen the technique.     

Controlled synthesis of polypeptides

Polypeptides are one kind of promising biodegradable and biocompatible biomedical polymers with the structural units of various α-amino acids. Polypeptides were first polymerized by the ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCAs) by Leuchs and Hermann in 1906. In the past decades, several effective strategies, including the selection of initiators, the adjustment of reaction conditions, and the introduction of catalysts, have been reported to improve the controllability of the ROP of various α-amino acid NCAs to synthesize different polypeptides with precise chemical structures and low polydispersity indexes. In this Review, the strategies, mechanisms, challenges, and opportunities for controlled synthesis of polypeptides by the ROP of different α-amino acid NCAs have been declared.     

CE-MS for metabolomics: Developments and applications in the period 2018–2020

Capillary electrophoresis-mass spectrometry (CE-MS) is now a mature analytical technique in metabolomics, notably for the efficient profiling of polar and charged metabolites. Over the past few years, (further) progress has been made in the design of improved interfacing techniques for coupling CE to MS; also, in the development of CE-MS approaches for profiling metabolites in volume-restricted samples, and in strategies that further enhance the metabolic coverage. In this article, which is a follow-up of a previous review article covering the years 2016–2018 (Electrophoresis 2019, 40, 165–179), the main (technological) developments in CE-MS methods and strategies for metabolomics are discussed covering the literature from July 2018 to June 2020. Representative examples highlight the utility of CE-MS in the fields of biomedical, clinical, microbial, plant and food metabolomics. A complete overview of recent CE-MS-based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings, and MS detection mode. Finally, some general conclusions and perspectives are given.     

基于微波光子学的准分布式光纤传感解调技术

准分布式光纤传感系统在土木工程、能源勘测、航空航天、国防、化工等领域一直发挥着不可替代的重要作用。以微波光子学为基础的准分布式光纤传感解调技术被广泛应用于光纤复用系统的快速、高精度的信号解调与传感器定位。与传统的光学波长解调方案相比,该技术大幅提高了系统的解调速率,弥补了传统解调方法在传感器定位方面的缺陷。本文主要介绍了近年来国内外在基于微波光子学的准分布式光纤传感解调领域的研究进展,从光纤光栅准分布式传感系统和光纤法布里-珀罗准分布式传感系统两方面入手,对比分析了现有的数种微波解调光纤准分布式系统的优缺点,并对基于微波光子学的准分布式光纤传感解调技术的未来发展方向进行了总结与展望。     

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).