30 research outputs found

    Incorporation of indole significantly improves the transfection efficiency of guanidinium‐containing poly(methacrylamide)s

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    Abstract A highly efficient transfection agent is reported that is based on terpolymer consisting of N ‐(2‐hydroxypropyl)methacrylamide (HPMA), N ‐(3‐guanidinopropyl) methacrylamide (GPMA), and N ‐(2‐indolethyl)methacrylamide monomers (IEMA) by analogy to the amphipathic cell‐penetrating peptides containing tryptophan and arginine residues. The incorporation of the indole‐bearing monomer leads to successful plasmid DNA condensation even at a nitrogen‐to‐phosphate (N/P) ratio of 1. The hydrodynamic diameter of polyplexes is determined to be below 200 nm for all N/P ratios. The transfection studies demonstrate a 200‐fold increase of the transgene expression in comparison to P(HPMA‐co‐GPMA) with the same guanidinium content. This study reveals the strong potential of the indole group as a side‐chain pendant group that can increase the cellular uptake of polymers and the transfection efficiency of the respective polyplexes

    Access to Digital Cultural Heritage: Innovative Applications of Automated Metadata Generation Chapter 1: Digitization of Cultural Heritage – Standards, Institutions, Initiatives

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    The first chapter "Digitization of Cultural Heritage – Standards, Institutions, Initiatives" provides an introduction to the area of digitisation. The main pillars of process of creating, preserving and accessing of cultural heritage in digital space are observed. The importance of metadata in the process of accessing to information is outlined. The metadata schemas and standards used in cultural heritage are discussed. In order to reach digital objects in virtual space they are organized in digital libraries. Contemporary digital libraries are trying to deliver richer and better functionality, which usually is user oriented and depending on current IT trend. Additionally, the chapter is focused on some initiatives on world and European level that during the years enforce the process of digitization and organizing digital objects in the cultural heritage domain. In recent years, the main focus in the creation of digital resources shifts from "system-centred" to "user-centred" since most of the issues around this content are related to making it accessible and usable for the real users. So, the user studies and involving the users on early stages of design and planning the functionality of the product which is being developed stands on leading position

    Indole, phenyl, and phenol Groups: The role of the comonomer on gene delivery in guanidinium containing methacrylamide terpolymers

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    Abstract This report highlights the importance of hydrophobic groups mimicking the side chains of aromatic amino acids, which are tryptophan, phenylalanine, and tyrosine, in guanidinium bearing poly(methacrylamide)s for the design of non‐viral gene delivery agents. Guanidinium containing methacrylamide terpolymers are prepared by aqueous reversible addition–fragmentation chain transfer ( a RAFT) polymerization with different hydrophobic monomers, N ‐(2‐indolethyl)methacrylamide (IEMA), N ‐phenethylmethacrylamide (PhEMA), or N ‐(4‐hydroxyphenethyl)methacrylamide (PhOHEMA) by aiming similar contents. The well‐defined polymers are obtained with a molar mass of ≈15 000 g mol −1 and ≈1.1 dispersity. All terpolymers demonstrate almost comparable in vitro cell viability and hemocompatibility profiles independent of the type of side chain. Although they all form positively charged, enzymatically stable polyplexes with plasmid DNA smaller than 200 nm, the incorporation of the IEMA monomer improve these parameters by demonstrating a higher DNA binding affinity and forming nanoassemblies of about 100 nm. These physicochemical characteristics are correlated with increased transfection rates in CHO‐K1 cells dependent on the type of the monomer and the nitrogen to phosphate (N/P) ratio of the polyplexes, as determined by luciferase reporter gene assays

    Influence of Lipid Heterogeneity and Phase Behavior on Phospholipase A2 Action at the Single Molecule Level

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    We monitored the action of phospholipase A2 (PLA2) on L- and D-dipalmitoylphosphatidylcholine (DPPC) Langmuir monolayers by mounting a Langmuir-trough on a wide-field fluorescence microscope with single molecule sensitivity. This made it possible to directly visualize the activity and diffusion behavior of single PLA2 molecules in a heterogeneous lipid environment during active hydrolysis. The experiments showed that enzyme molecules adsorbed and interacted almost exclusively with the fluid region of the DPPC monolayers. Domains of gel state L-DPPC were degraded exclusively from the gel-fluid interface where the build-up of negatively charged hydrolysis products, fatty acid salts, led to changes in the mobility of PLA2. The mobility of individual enzymes on the monolayers was characterized by single particle tracking (SPT). Diffusion coefficients of enzymes adsorbed to the fluid interface were between 3 mu m^2/s on the L-DPPC and 4.6 mu m^/s on the D-DPPC monolayers. In regions enriched with hydrolysis products the diffusion dropped to approx. 0.2 mu m^2/s. In addition, slower normal and anomalous diffusion modes were seen at the L-DPPC gel domain boundaries where hydrolysis took place. The average residence times of the enzyme in the fluid regions of the monolayer and on the product domain were between approx. 30 and 220 ms. At the gel domains it was below the experimental time resolution, i.e. enzymes were simply reflected from the gel domains back into solution.Comment: 10 pages, 10 figure

    ï»żLevel of hypertension treatment adherence during pandemic

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    Adherence to antihypertensive medications is the cornerstone for achieving metabolic syndrome control. The aim of this study was to explore how the pandemic has affected the adherence of patients with high BP to prescribed antihypertensive drugs. This multicentre observational study utilized self-completed questionnaires among patients between June and November 2020. Overall, 842 patients were included in the study. The likelihood of adherence was assessed using the 5‐item version of the Medication Adherence Report Scale (MARS-5Professor Rob Horne). The average MARS score of the sample was 16.81, the median was 4.162, and the most common value was 3 (24.5% of respondents) for the patients treated during the pandemic. The study suggests that several sociodemographic factors but not the COVID pandemic play a role in treatment adherence

    Making Photocatalysts Screenable - A Milli Scale Multi-Batch Screening Photoreactor as Extension for the Modular Photoreactor

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    Development and evaluation of new photocatalytic systems requires screening of large parameter spaces. For such investigations, a photonically characterized, simple, and low-cost multi-batch screening photoreactor is presented that enables the screening of up to 49 sealed 4 mL milli batch reactors. The reactor concept is based on theoretical contemplation of the geometrical and optical properties of suited reflector concepts and utilizes basic components of the modular photoreactor introduced recently. Raytracing, radiometry and chemical actinometry were used for the photonic characterization. Applicability of the screening setup under catalytic conditions was evaluated using a benchmark system for photoinduced hydrogen evolution consisting of [Ru(bpy)3](PF6)2 as photosensitizer, ascorbic acid as sacrificial agent and Mo3S132- as catalyst. Extending screening to metal-free organic photosensitizers, bimane compounds are reported as photosensitizers for photoinduced hydrogen evolution in various catalytic systems
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