TY - JOUR A1 - Hoogenboom, Richard A1 - Schlaad, Helmut T1 - Thermoresponsive poly(2-oxazoline)s, polypeptoids, and polypeptides JF - Polymer Chemistry N2 - This review covers the recent advances in the emerging field of thermoresponsive polyamides or polymeric amides, i.e., poly(2-oxazoline)s, polypeptoids, and polypeptides, with a specific focus on structure-thermoresponsive property relationships, self-assembly, and applications. Y1 - 2016 U6 - https://doi.org/10.1039/c6py01320a SN - 1759-9954 SN - 1759-9962 VL - 8 IS - 1 SP - 24 EP - 40 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Yarman, Aysu A1 - Kurbanoglu, Sevinc A1 - Jetzschmann, Katharina J. A1 - Ozkan, Sibel A. A1 - Wollenberger, Ulla A1 - Scheller, Frieder W. T1 - Electrochemical MIP-Sensors for Drugs JF - Current Medicinal Chemistry N2 - In order to replace bio-macromolecules by stable synthetic materials in separation techniques and bioanalysis biomimetic receptors and catalysts have been developed: Functional monomers are polymerized together with the target analyte and after template removal cavities are formed in the "molecularly imprinted polymer" (MIP) which resemble the active sites of antibodies and enzymes. Starting almost 80 years ago, around 1,100 papers on MIPs were published in 2016. Electropolymerization allows to deposit MIPs directly on voltammetric electrodes or chips for quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). For the readout of MIPs for drugs amperometry, differential pulse voltammetry (DPV) and impedance spectroscopy (EIS) offer higher sensitivity as compared with QCM or SPR. Application of simple electrochemical devices allows both the reproducible preparation of MIP sensors, but also the sensitive signal generation. Electrochemical MIP-sensors for the whole arsenal of drugs, e.g. the most frequently used analgesics, antibiotics and anticancer drugs have been presented in literature and tested under laboratory conditions. These biomimetic sensors typically have measuring ranges covering the lower nano-up to millimolar concentration range and they are stable under extreme pH and in organic solvents like nonaqueous extracts. KW - Biomimetic sensors KW - molecularly imprinted polymers KW - drug sensors KW - drug imprinting KW - electropolymerization KW - electrochemical sensors Y1 - 2018 U6 - https://doi.org/10.2174/0929867324666171005103712 SN - 0929-8673 SN - 1875-533X VL - 25 IS - 33 SP - 4007 EP - 4019 PB - Bentham Science Publishers LTD CY - Sharjah ER - TY - JOUR A1 - Bornhorst, Julia A1 - Kipp, Anna P. A1 - Haase, Hajo A1 - Meyer, Soeren A1 - Schwerdtle, Tanja T1 - The crux of inept biomarkers for risks and benefits of trace elements JF - Trends in Analytical Chemistry N2 - Nowadays, the role of trace elements (TE) is of growing interest because dyshomeostasis of selenium (Se), manganese (Mn), zinc (Zn), and copper (Cu) is supposed to be a risk factor for several diseases. Thereby, research focuses on identifying new biomarkers for the TE status to allow for a more reliable description of the individual TE and health status. This review mirrors a lack of well-defined, sensitive, and selective biomarkers and summarizes technical limitations to measure them. Thus, the capacity to assess the relationship between dietary TE intake, homeostasis, and health is restricted, which would otherwise provide the basis to define adequate intake levels of single TE in both healthy and diseased humans. Besides that, our knowledge is even more limited with respect to the real life situation of combined TE intake and putative interactions between single TE. KW - Trace elements KW - Copper KW - Zinc KW - Manganese KW - Selenium KW - Biomarker KW - Inductively coupled plasma mass spectrometry KW - Hyphenated techniques KW - Isotope ratios Y1 - 2018 U6 - https://doi.org/10.1016/j.trac.2017.11.007 SN - 0165-9936 SN - 1879-3142 VL - 104 SP - 183 EP - 190 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Fudickar, Werner A1 - Linker, Torsten T1 - Release of Singlet Oxygen from Organic Peroxides under Mild Conditions JF - ChemPhotoChem N2 - Singlet oxygen can be released in the dark in nearly quantitative yield from endoperoxides of naphthalenes, anthracenes and pyridones as an alternative to its generation by photosensitization. Recently, new donor systems have been designed which operate at very low temperatures but which are prepared from their parent forms at acceptable rates. Enhancement of the reactivity of donors is conveniently achieved by the design of the substitution pattern or through the use of plasmonic heating of nanoparticle-bound donors. The most important aim of these donor molecules is to transfer singlet oxygen in a controlled and directed manner to a target. Low temperatures and the linking between donors and acceptors reduce the random walk of oxygen and may force an attack at the desired position. By using chiral donor systems, new stereocenters might be introduced into prochiral acceptors. KW - donor-acceptor systems KW - oxygenation KW - peroxides KW - polycycles KW - retro reactions Y1 - 2018 U6 - https://doi.org/10.1002/cptc.201700235 SN - 2367-0932 VL - 2 IS - 7 SP - 548 EP - 558 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mota, Cristiano A1 - Coelho, Catarina A1 - Leimkühler, Silke A1 - Garattini, Enrico A1 - Terao, Mineko A1 - Santos-Silva, Teresa A1 - Romao, Maria Joao T1 - Critical overview on the structure and metabolism of human aldehyde oxidase and its role in pharmacokinetics JF - Coordination chemistry reviews N2 - Aldehyde oxidases are molybdenum and flavin dependent enzymes characterized by a very wide substrate specificity and performing diverse reactions that include oxidations (e.g., aldehydes and azaheterocycles), hydrolysis of amide bonds, and reductions (e.g., nitro, S-oxides and N-oxides). Oxidation reactions and amide hydrolysis occur at the molybdenum site while the reductions are proposed to occur at the flavin site. AOX activity affects the metabolism of different drugs and xenobiotics, some of which designed to resist other liver metabolizing enzymes (e.g., cytochrome P450 monooxygenase isoenzymes), raising its importance in drug development. This work consists of a comprehensive overview on aldehyde oxidases, concerning the genetic evolution of AOX, its diversity among the human population, the crystal structures available, the known catalytic reactions and the consequences in pre-clinical pharmacokinetic and pharmacodynamic studies. Analysis of the different animal models generally used for pre-clinical trials and comparison between the human (hAOX1), mouse homologs as well as the related xanthine oxidase (XOR) are extensively considered. The data reviewed also include a systematic analysis of representative classes of molecules that are hAOX1 substrates as well as of typical and well characterized hAOX1 inhibitors. The considerations made on the basis of a structural and functional analysis are correlated with reported kinetic and metabolic data for typical classes of drugs, searching for potential structural determinants that may dictate substrate and/or inhibitor specificities. KW - Drug metabolism KW - Aldehyde oxidase KW - Xenobiotics KW - Molybdoenzymes KW - Non-CYP enzymes KW - Hepatic clearance Y1 - 2018 U6 - https://doi.org/10.1016/j.ccr.2018.04.006 SN - 0010-8545 SN - 1873-3840 VL - 368 SP - 35 EP - 59 PB - Elsevier CY - Lausanne ER - TY - JOUR A1 - Heck, Christian A1 - Michaeli, Yael A1 - Bald, Ilko A1 - Ebenstein, Yuval T1 - Analytical epigenetics BT - single-molecule optical detection of DNA and histone modifications JF - Current Opinion in Biotechnology N2 - The field of epigenetics describes the relationship between genotype and phenotype, by regulating gene expression without changing the canonical base sequence of DNA. It deals with molecular genomic information that is encoded by a rich repertoire of chemical modifications and molecular interactions. This regulation involves DNA, RNA and proteins that are enzymatically tagged with small molecular groups that alter their physical and chemical properties. It is now clear that epigenetic alterations are involved in development and disease, and thus, are the focus of intensive research. The ability to record epigenetic changes and quantify them in rare medical samples is critical for next generation diagnostics. Optical detection offers the ultimate single-molecule sensitivity and the potential for spectral multiplexing. Here we review recent progress in ultrasensitive optical detection of DNA and histone modifications. Y1 - 2018 U6 - https://doi.org/10.1016/j.copbio.2018.09.006 SN - 0958-1669 SN - 1879-0429 VL - 55 SP - 151 EP - 158 PB - Elsevier CY - London ER - TY - JOUR A1 - Hu, Shuangyan A1 - Zhao, Junpeng A1 - Zhang, Guangzhao A1 - Schlaad, Helmut T1 - Macromolecular architectures through organocatalysis JF - Progress in Polymer Science N2 - In virtue of the rising demand for metal-free polymeric materials, organocatalytic polymerization has emerged and blossomed unprecedentedly in the past 15 years into an appealing research area and a powerful arsenal for polymer synthesis. In addition to the inherent merits as being metal-free, small molecule organocatalysts have also provided opportunities to develop alternative and, in many cases, more expedient synthetic approaches toward macromolecular architectures, that play a crucial role in shaping the properties of the obtained polymers. A majority of preliminary studies exploring for new catalysts, catalytic mechanisms and optimized polymerization conditions are extended to application of the catalytic systems on rational design and controlled synthesis of various macromolecular architectures. Such endeavors are described in this review, categorized by the architectural elements including chain structure (types, sequence and composition of monomeric units constituting the polymer chains), topological structure (the fashion different polymer chains are covalently attached to each other within the macromolecule) and functionality (position and amount of functional groups that endow the entire macromolecule with specific chemical, physico-chemical or biological properties). (C) 2017 Published by Elsevier B.V. KW - Organocatalytic polymerization KW - Metal-free polymerization KW - Macromolecular architecture KW - Controlled polymer synthesis Y1 - 2017 U6 - https://doi.org/10.1016/j.progpolymsci.2017.07.002 SN - 0079-6700 SN - 1873-1619 VL - 74 SP - 34 EP - 77 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Braune, Steffen A1 - Latour, Robert A. A1 - Reinthaler, Markus A1 - Landmesser, Ulf A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - In Vitro Thrombogenicity Testing of Biomaterials JF - Advanced healthcare materials N2 - The short- and long-term thrombogenicity of implant materials is still unpredictable, which is a significant challenge for the treatment of cardiovascular diseases. A knowledge-based approach for implementing biofunctions in materials requires a detailed understanding of the medical device in the biological system. In particular, the interplay between material and blood components/cells as well as standardized and commonly acknowledged in vitro test methods allowing a reproducible categorization of the material thrombogenicity requires further attention. Here, the status of in vitro thrombogenicity testing methods for biomaterials is reviewed, particularly taking in view the preparation of test materials and references, the selection and characterization of donors and blood samples, the prerequisites for reproducible approaches and applied test systems. Recent joint approaches in finding common standards for a reproducible testing are summarized and perspectives for a more disease oriented in vitro thrombogenicity testing are discussed. KW - biomaterials KW - blood tests KW - implants KW - in vitro KW - thrombogenicity Y1 - 2019 U6 - https://doi.org/10.1002/adhm.201900527 SN - 2192-2640 SN - 2192-2659 VL - 8 IS - 21 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Wolff, Christian Michael A1 - Caprioglio, Pietro A1 - Stolterfoht, Martin A1 - Neher, Dieter T1 - Nonradiative Recombination in Perovskite Solar Cells BT - the Role of Interfaces JF - Advanced materials N2 - Perovskite solar cells combine high carrier mobilities with long carrier lifetimes and high radiative efficiencies. Despite this, full devices suffer from significant nonradiative recombination losses, limiting their V-OC to values well below the Shockley-Queisser limit. Here, recent advances in understanding nonradiative recombination in perovskite solar cells from picoseconds to steady state are presented, with an emphasis on the interfaces between the perovskite absorber and the charge transport layers. Quantification of the quasi-Fermi level splitting in perovskite films with and without attached transport layers allows to identify the origin of nonradiative recombination, and to explain the V-OC of operational devices. These measurements prove that in state-of-the-art solar cells, nonradiative recombination at the interfaces between the perovskite and the transport layers is more important than processes in the bulk or at grain boundaries. Optical pump-probe techniques give complementary access to the interfacial recombination pathways and provide quantitative information on transfer rates and recombination velocities. Promising optimization strategies are also highlighted, in particular in view of the role of energy level alignment and the importance of surface passivation. Recent record perovskite solar cells with low nonradiative losses are presented where interfacial recombination is effectively overcome-paving the way to the thermodynamic efficiency limit. KW - interfacial recombination KW - open-circuit voltage KW - perovskite solar cells KW - photoluminescence Y1 - 2019 U6 - https://doi.org/10.1002/adma.201902762 SN - 0935-9648 SN - 1521-4095 VL - 31 IS - 52 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schöne, Anne-Christin A1 - Roch, Toralf A1 - Schulz, Burkhard A1 - Lendlein, Andreas T1 - Evaluating polymeric biomaterial-environment interfaces by Langmuir monolayer techniques JF - Interface : journal of the Royal Society N2 - Polymeric biomaterials are of specific relevance in medical and pharmaceutical applications due to their wide range of tailorable properties and functionalities. The knowledge about interactions of biomaterials with their biological environment is of crucial importance for developing highly sophisticated medical devices. To achieve optimal in vivo performance, a description at the molecular level is required to gain better understanding about the surface of synthetic materials for tailoring their properties. This is still challenging and requires the comprehensive characterization of morphological structures, polymer chain arrangements and degradation behaviour. The review discusses selected aspects for evaluating polymeric biomaterial-environment interfaces by Langmuir monolayer methods as powerful techniques for studying interfacial properties, such as morphological and degradation processes. The combination of spectroscopic, microscopic and scattering methods with the Langmuir techniques adapted to polymers can substantially improve the understanding of their in vivo behaviour. KW - Langmuir monolayer KW - biodegradable polymers KW - air - water interface KW - protein Langmuir layers Y1 - 2017 U6 - https://doi.org/10.1098/rsif.2016.1028 SN - 1742-5689 SN - 1742-5662 VL - 14 PB - Royal Society CY - London ER -