Search results for "Acrylates"
showing 10 items of 115 documents
Series of fibrinous inflammation after implantation of capsular tension rings
2014
Purpose To analyze the cause of fibrinous inflammation in eyes with capsular tension rings (CTRs) after cataract surgery. Setting Department of Ophthalmology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany. Design Retrospective case series. Methods High-performance liquid chromatography was implemented to eliminate impurities. One CTR was explanted for microbiologic examination. The pH values of the CTR and the storage solution were analyzed, Seldi and Maldi tests were performed, as well as toxicity tests with immortal cell lines. Material batches were analyzed. The organic carbon content of CTRs, detergents, and storage solutions was checked. The presence of…
Enteroscopic Cyanoacrylate Sclerotherapy of Jejunal and Gallbladder Varices in a Patient with Portal Hypertension
2001
Bleeding from varices outside the gastroesophageal region is a rare, but regularly reported complication of portal hypertension. The treatment differs from the management of esophageal and gastric varices. We present here a report on the diagnosis and treatment of bleeding jejunal and gallbladder varices in a man with portal hypertension caused by chronic calcifying pancreatitis. The patient was suffering from recurrent, frequent, and massive gastrointestinal bleeding from varices at the anastomotic area of a cholecystojejunostomy. For diagnostic purposes, we carried out percutaneous Duplex ultrasonography and push enteroscopy with the Doppler technique. The treatment of varices in this are…
Effect of a closed foldable equator ring on capsular bag shrinkage in cataract surgery.
2005
To evaluate the effect of a closed foldable equator ring (CFER) versus a conventional capsular tension ring (CTR) on capsular bag shrinkage.Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.In this prospective study, 70 eyes of 70 patients were randomized to 2 groups using a 1:1 block scheme. After uneventful cataract surgery, a capsular measuring ring was implanted in all eyes to measure the capsular bag diameter in vivo. In Group 1, a CTR was implanted in the capsular bag. In Group 2, a CFER was inserted. Biometric characteristics such as axial length and the horizontal and vertical corneal radii were measured preoperatively. The capsular bag diameter and capsulor…
A New Hyaluronic Acid Derivative Obtained from Atom Transfer Radical Polymerization as a siRNA Vector for CD44 Receptor Tumor Targeting.
2015
Two derivatives of hyaluronic acid (HA) have been synthesized by atom transfer radical polymerization (ATRP), starting from an ethylenediamino HA derivative (HA-EDA) and by using diethylaminoethyl methacrylate (DEAEMA) as a monomer for polymerization. Both samples, indicated as HA-EDA-pDEAEMA a and b, are able to condense siRNA, as determined by gel retardation assay and resulting complexes show a size and a zeta potential value dependent on polymerization number, as determined by dynamic light scattering measurements. In vitro studies performed on HCT 116 cell line, that over express CD44 receptor, demonstrate a receptor mediated uptake of complexes, regardless of their surface charge. New…
Iris-Like Tunable Aperture Employing Liquid-Crystal Elastomers
2014
A liquid-crystal elastomer (LCE) iris inspired by the human eye is demonstrated. With integrated polyimide-based platinum heaters, the LCE material is thermally actuated. The radial contraction direction, similar to a mammalian iris, is imprinted to the LCE by a custom-designed magnetic field. Actuation of the device is reproducible over multiple cycles and controllable at intermediate contraction states.
Toward potent antibiofilm degradable medical devices: A generic method for the antibacterial surface modification of polylactide
2013
International audience; The effects of biomaterials on their environment must be carefully modulated in most biomedical applications. Among other approaches, this modulation can be obtained through the modification of the biomaterial surface. This paper proposes a simple and versatile strategy to produce non-leaching antibacterial polylactide (PLA) surfaces without any degradation of the polyester chains. The method is based on a one-pot procedure that provides a "clickable" PLA surface via anionic activation which is then functionalized with an antibacterial quaternized poly(2-(dimethylamino)ethyl methacrylate) (QPDMAEMA) by covalent immobilization on the surface. The anti-adherence and an…
Preparation, characterization and in vitro antimicrobial activity of ampicillin-loaded polyethylcyanoacrylate nanoparticles.
1998
In this paper, the experimental conditions for preparing ampicillin-loaded polyethylcyanoacrylate (PECA) nanoparticles are described. The effects of drug concentration and surfactant type in the polymerization medium on the particle size distribution and loading capacity were studied. The results of these studies show that only the type of surfactant has an impact on the nanoparticle dimensions. The release rate of ampicillin from PECA nanoparticles at pH 7.4 (extracellular value pH) performed either with and without esterases, show that the drug release is considerably increased in the presence of these exzymes. The results of drug release study at pH 1.1 (simulated gastric juice) are very…
Preparation and evaluation of butyl acrylate-based monolithic columns for CEC using ammonium peroxodisulfate as a chemical initiator.
2008
Acrylate-ester-based monoliths for CEC using peroxodisulfate as a chemical initiator were prepared. The influence of two ternary porogenic solvents on the physical and chromatographic properties of butyl acrylate monolithic stationary phases was investigated. The composition and the ratio of porogenic solvent were adjusted to obtain highly permeable rigid monoliths with adequate column efficiency. Among the prepared butyl acrylate monoliths, those polymerized from a ternary porogenic solvent of acetonitrile/ethanol/water exhibited the most promising performance with a minimum plate height for naphthalene of 10.5 microm and a bed permeability of 7.3 x 10(-14) m(2). A comparison in terms of e…
Nanostructuring with a crosslinkable discotic material.
2007
A high-yielding synthesis afforded a hexa-peri-hexabenzocoronene carrying acrylate units at the end of six attached alkyl spacers. The polymerization of these acrylate moieties could be initiated with thermal energy and through direct photoactivation without the addition of a photoinitiator. This allowed the organization of the liquid-crystalline material to be fixed in either the crystalline state or the mesophase, which preserved the organization in the respective phase. The use of a focused synchrotron beam permitted selected regions of a thin film to be rendered insoluble. After "developing" the film in this lithographic process by dissolving the soluble, unpolymerized material, defined…
Amoxicillin-loaded polyethylcyanoacrylate nanoparticles: influence of PEG coating on the particle size, drug release rate and phagocytic uptake.
2001
Polyethyleneglycol (PEG)-coated polyethylcyanoacrylate (PECA) nanoparticles loaded with amoxicillin were prepared and the influence of the PEG coating on the particle size, zeta potential, drug release rate and phagocytic uptake by murine macrophages was studied. Experimental results show that this colloidal drug delivery system could be useful for intravenous or oral administration. The profile of amoxicillin release from PECA nanoparticles system was studied under various conditions similar to those of some corporeal fluids. In all these experiments, amoxicillin release in the free form was studied by HPLC analysis. Experimental results showed that at pH 7.4 drug release rises when molecu…