Search results for "Hydrophobic and Hydrophilic Interactions"
showing 10 items of 189 documents
Comparative study of taurine and tauropyrone: GABA receptor binding, mitochondrial processes and behaviour.
2011
Abstract Objectives Taurine, a sulfur-containing amino acid, has high hydrophilicity and is poorly absorbed. Tauropyrone, a taurine-containing 1,4-dihydropyridine derivative, is suggested to have greater activity than taurine owing to improved physicochemical properties that facilitate delivery of the compound to target cells. The aim of this study was to determine whether the 1,4-dihydropyridine moiety in tauropyrone improves the pharmacological efficacy of taurine in vitro and in vivo. Methods The effects of taurine and tauropyrone, as well as of the 1,4-dihydropyridine moiety were compared in in-vitro experiments to determine the binding to GABA receptors and influence on mitochondrial p…
Supramolecular Design of Low-dimensional Carbon Nano-hybrids encoding a Polyoxometalate-bis-Pyrene Tweezer
2014
A novel bis-pyrene tweezer anchored on a rigid polyoxometalate scaffold fosters a unique interplay of hydrophobic and electrostatic supramolecular interactions, to shape carbon nanostructures (CNSs)-based extended architectures.
Nanocapsules with specific targeting and release properties using miniemulsion polymerization.
2013
The field of application for nanosized materials ranges from mere technical purposes to a growing field of applications in biomedicine. Among the different techniques and processes to produce these materials for encapsulation of reporter molecules and drugs, the miniemulsion process has been proven to be highly adaptable to these specific needs.The review covers the recent developments in the field of miniemulsion as a very powerful technique for the formation of complex carriers for the encapsulation of different kinds of reporter molecule and drugs. The use of a wide variety of polymerization techniques in the miniemulsion process and possible utilization of a wide range of monomers as re…
Imbibition of Femtoliter-Scale DNA-Rich Aqueous Droplets into Porous Nylon Substrates by Molecular Printing
2019
This work presents the first reported imbibition mechanism of femtoliter (fL)-scale droplets produced by microchannel cantilever spotting (μCS) of DNA molecular inks into porous substrates (hydrophilic nylon). Differently from macroscopic or picoliter droplets, the downscaling to the fL-size leads to an imbibition process controlled by the subtle interplay of evaporation, spreading, viscosity, and capillarity, with gravitational forces being quasi-negligible. In particular, the minimization of droplet evaporation, surface tension, and viscosity allows for a reproducible droplet imbibition process. The dwell time on the nylon surface permits further tuning of the droplet lateral size, in acc…
From the solution processing of hydrophilic molecules to polymer-phthalocyanine hybrid materials for ammonia sensing in high humidity atmospheres.
2014
We have prepared different hybrid polymer-phthalocyanine materials by solution processing, starting from two sulfonated phthalocyanines, s-CoPc and CuTsPc, and polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly(acrylic acid-co-acrylamide) (PAA-AM), poly(diallyldimethylammonium chloride) (PDDA) and polyaniline (PANI) as polymers. We also studied the response to ammonia (NH3) of resistors prepared from these sensing materials. The solvent casted films, prepared from s-CoPc and PVP, PEG and PAA-AM, were highly insulating and very sensitive to the relative humidity (RH) variation. The incorporation of s-CoPc in PDDA by means of layer-by-layer (LBL) technique allowed to stabilize the fi…
Ruthenium-Containing Block Copolymer Assemblies: Red-Light-Responsive Metallopolymers with Tunable Nanostructures for Enhanced Cellular Uptake and An…
2015
The use of self-assembled nanostructures consisting of red-light-responsive Ru(II)-containing block copolymers (BCPs) for anticancer phototherapy is demonstrated. Three Ru-containing BCPs with different molecular weights are synthesized. Each BCP contains a hydrophilic poly(ethylene glycol) block and an Ru-containing block. In the Ru-containing block, more than half of the side chains are coordinated with [Ru(2,2':6',2''-terpyridine)(2,2'-biquinoline)](2+) , resulting in more than 40 wt% Ru complex in the BCPs. The Ru complex acts as both a red-light-cleavable moiety and a photoactivated prodrug. Depending on their molecular weights, the BCPs assemble into micelles, vesicles, and large comp…
Elastic Superhydrophobic and Photocatalytic Active Films Used as Blood Repellent Dressing.
2020
Durable and biocompatible superhydrophobic surfaces are of significant potential use in biomedical applications. Here, a nonfluorinated, elastic, superhydrophobic film that can be used for medical wound dressings to enhance their hemostasis function is introduced. The film is formed by titanium dioxide nanoparticles, which are chemically crosslinked in a poly(dimethylsiloxane) (PDMS) matrix. The PDMS crosslinks result in large strain elasticity of the film, so that it conforms to deformations of the substrate. The photocatalytic activity of the titanium dioxide provides surfaces with both self-cleaning and antibacterial properties. Facile coating of conventional wound dressings is demonstra…
Amphiphilic polyaspartamide copolymer-based micelles for rivastigmine delivery to neuronal cells
2012
A novel polysorbate-80 (PS(80))-attached amphiphilic copolymer comprising a hydrophilic α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) backbone and hydrophobic squalenyl-C(17) (Sq(17)) portions was synthesized and characterized; the formation of polymeric micelles was also evaluated. Rivastigmine free-base (Riv), a hydrophobic drug employed to treat Alzheimer's disease, was chosen as model drug to investigate micelle's ability to incorporate hydrophobic molecules and target them to neuronal cells. Micelle formation was studied through analyses including fluorescence spectroscopy and 2D (1)H-NMR NOESY experiments. Finally, the capacity of Riv-loaded micelles, versus free drug, to penetrat…
Reversible Modulation of Elasticity in Fluoroazobenzene-Containing Hydrogels Using Green and Blue Light.
2017
Hydrogels are soft materials that have found multiple applications in biomedicine and represent a good platform for the introduction of molecular switches and synthetic machines into macromolecular networks. Tuning their mechanical properties reversibly with light is appealing for a variety of advanced applications and has been demonstrated in the past; however, their activation typically requires the use of UV light, which displays several drawbacks related to its damaging character and limited penetration in tissues and materials. This study circumvents this limitation by introducing all-visible ortho-fluoroazobenzene switches into a hydrophilic network, which, as a result, can be activat…
Endocytotic uptake of HPMA-based polymers by different cancer cells: impact of extracellular acidosis and hypoxia.
2017
Daniel Gündel,1 Mareli Allmeroth,2 Sarah Reime,1 Rudolf Zentel,2 Oliver Thews1 1Institute of Physiology, Martin Luther University Halle-Wittenberg, Halle (Saale), 2Institute of Organic Chemistry, Johannes Gutenberg-University, Mainz, Germany Background: Polymeric nanoparticles allow to selectively transport chemotherapeutic drugs to the tumor tissue. These nanocarriers have to be taken up into the cells to release the drug. In addition, tumors often show pathological metabolic characteristics (hypoxia and acidosis) which might affect the polymer endocytosis.Materials and methods: Six different N-(2-hydroxypropyl)methacrylamide (HPMA)-based polymer structures (homopolymer as well as…