30 research outputs found
Incorporation of indole significantly improves the transfection efficiency of guanidiniumâcontaining poly(methacrylamide)s
Abstract A highly efficient transfection agent is reported that is based on terpolymer consisting of N â(2âhydroxypropyl)methacrylamide (HPMA), N â(3âguanidinopropyl) methacrylamide (GPMA), and N â(2âindolethyl)methacrylamide monomers (IEMA) by analogy to the amphipathic cellâpenetrating peptides containing tryptophan and arginine residues. The incorporation of the indoleâbearing monomer leads to successful plasmid DNA condensation even at a nitrogenâtoâphosphate (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 200âfold increase of the transgene expression in comparison to P(HPMAâcoâGPMA) with the same guanidinium content. This study reveals the strong potential of the indole group as a sideâchain 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 â Standards, Institutions, Initiatives
The first chapter "Digitization of Cultural Heritage â 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
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 nonâviral gene delivery agents. Guanidinium containing methacrylamide terpolymers are prepared by aqueous reversible additionâfragmentation chain transfer ( a RAFT) polymerization with different hydrophobic monomers, N â(2âindolethyl)methacrylamide (IEMA), N âphenethylmethacrylamide (PhEMA), or N â(4âhydroxyphenethyl)methacrylamide (PhOHEMA) by aiming similar contents. The wellâdefined polymers are obtained with a molar mass of â15â000 g mol â1 and â1.1 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 CHOâK1 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
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
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 5âitem 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
Exploiting the Nitrilotriacetic Acid Moiety for Biolabeling with Ultrastable Perylene Dyes
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1,7,9,10-Tetrasubstituted PMIs Accessible through Decarboxylative Bromination: Synthesis, Characterization, Photophysical Studies, and Hydrogen Evolution Catalysis
In this work, we present a new synthetic strategy for fourfold-substituted perylene monoimides via tetrabrominated perylene monoanhydrides. X-ray diffraction analysis unveiled the intramolecular stacking orientation between the substituents and semicircular packing behavior. We observed the remarkable influence of the substituent on the longevity and nature of the excited state upon visible light excitation. In the presence of poly(dehydroalanine)-graft-poly(ethylene glycol) graft copolymers as solubilizing template, the chromophores are capable of sensitizing [Mo3S13]2â clusters in aqueous solution for stable visible light driven hydrogen evolution over three days. © 2020 The Authors. Chemistry - A European Journal published by Wiley-VCH Gmb
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Full membrane spanning self-assembled monolayers as model systems for UHV-based studies of cell-penetrating peptides
Biophysical studies of the interaction of peptides with model membranes provide a simple yet effective approach to understand the transport of peptides and peptide based drug carriers across the cell membrane. Herein, the authors discuss the use of self-assembled monolayers fabricated from the full membrane-spanning thiol (FMST) 3-((14-((40-((5-methyl-1-phenyl-35-(phytanyl)oxy- 6,9,12,15,18,21,24,27,30,33,37-undecaoxa-2,3-dithiahenpentacontan-51-yl)oxy)-[1,10-biphenyl]-4- yl)oxy)tetradecyl)oxy)-2-(phytanyl)oxy glycerol for ultrahigh vacuum (UHV) based experiments. UHV-based methods such as electron spectroscopy and mass spectrometry can provide important information about how peptides bind and interact with membranes, especially with the hydrophobic core of a lipid bilayer. Near-edge x-ray absorption fine structure spectra and x-ray photoelectron spectroscopy (XPS) data showed that FMST forms UHV-stable and ordered films on gold. XPS and time of flight secondary ion mass spectrometry depth profiles indicated that a proline-rich amphipathic cell-penetrating peptide, known as sweet arrow peptide is located at the outer perimeter of the model membrane.This is the publisherâs final pdf. The article is copyrighted by the American Vacuum Society and published by the American Institute of Physics Publishing. It can be found at: http://scitation.aip.org/content/avs/journal/bip;jsessionid=1g93rvqb7shb6.x-aip-live-03
Making Photocatalysts Screenable - A Milli Scale Multi-Batch Screening Photoreactor as Extension for the Modular Photoreactor
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