Search results for "Acrylates"
showing 10 items of 115 documents
Ahmed valve, suture-less implantation: A new approach to an easier technique.
2013
Purpose Tissue adhesives have been used in ophthalmology instead of sutures to minimize the operating time. This case series investigated the effectiveness and safety of use of cyanoacrylate in Ahmed valve implantation through pars plana for refractory glaucoma. Patients and methods Seventeen eyes of 17 patients with refractory glaucoma underwent Ahmed valve scleral suture-less implantation through pars plana with a cyanoacrylate suture of the plate. Refractory glaucoma was defined as intraocular pressure (IOP) ≥ 21 mm Hg with antiglaucoma eye drops, good adherence to treatment, and no previous glaucoma surgery. IOP control and development of complications were evaluated during the follow-u…
Biostable Scaffolds of Polyacrylate Polymers Implanted in the Articular Cartilage Induce Hyaline-Like Cartilage Regeneration in Rabbits
2017
[EN] Purpose: To study the influence of scaffold properties on the organization of ¿in vivo¿ cartilage regeneration. Our hypothesis is that stress transmission to the cells seeded inside the scaffold pores or surrounding it, which is highly dependent on the scaffold properties, determine differentiation of both mesenchymal cells and dedifferentiated autologous chondrocytes. Methods: Four series of porous scaffolds made of different polyacrylate polymers, previously seeded with cultured rabbit chondrocytes or without cells preseeded, were implanted in cartilage defects in rabbits. Subchondral bone was always injured during the surgery in order to allow blood to reach the implantation site an…
Chemical initiation for butyl and lauryl acrylate monolithic columns for CEC.
2009
Butyl acrylate (BA)- and lauryl acrylate (LA)-based monolithic stationary phases for CEC were synthesized, using a redox system as initiator of polymerization. BA monoliths were initiated with ammonium peroxodisulfate, whereas LA columns were obtained with lauroyl peroxide as initiator. In both cases, TEMED was used to activate the process. The influence of porogenic solvent composition on both morphological and electrochromatographic properties of the resulting monoliths was investigated. Excellent efficiencies (minimum plate heights of 4.2-6.3 microm for BA columns and 2.6-5.3 microm for LA stationary phases, for a PAHs mixture) were achieved. The capability of separation of both types of…
Lauroyl peroxide as thermal initiator of lauryl methacrylate monolithic columns for CEC
2008
The preparation of lauryl methacrylate (LMA)-based monolithic columns for CEC using lauroyl peroxide (LPO) as thermal initiator of polymerization has been investigated. The influence of initiator amount and composition of porogenic solvent on the physical and electrochromatographic properties of the resulting LMA-based monoliths was evaluated. A comparison with LMA-based columns thermally polymerized with AIBN was performed. At a given porogenic solvent composition, LMA stationary phases initiated with LPO showed higher permeabilities and better efficiency values than those prepared using AIBN as initiator. The optimum polymerization mixture found for LPO initiator provided a minimum plate …
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…
Zwitterionic codeine-derived methacrylate monoliths for enantioselective capillary electrochromatography of chiral acids and chiral bases
2018
Thiol-ene click reaction of N-acetyl-L-cysteine methyl ester to codeine, followed by reaction with allyl isocyanate and hydrolysis to the corresponding zwitterionic chiral selector and its subsequent bonding to the surface of a methacrylate monolith provided a new chiral capillary column for enantiomer separation of chiral acids and chiral bases. First, the epoxy groups of a poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith were converted into amine residues, followed by reaction with allylglycidyl ether. In this way, a spacer arm was bonded to the surface before coating and cross-linking poly(3-mercaptopropyl methylsiloxane) (PMPMS) via radical addition (thiol-ene click react…
The European multicenter cohort study on cyanoacrylate embolization of refluxing great saphenous veins
2014
ObjectiveCyanoacrylate (CA) embolization of refluxing great saphenous veins (GSVs) has been previously described. The outcomes from a multicenter study are still lacking.MethodsA prospective multicenter study was conducted in seven centers in four European countries to abolish GSV reflux by endovenous CA embolization. Neither tumescent anesthesia nor postinterventional compression stockings were used. Varicose tributaries remained untreated until at least 3 months after the index treatment. Clinical examination, quality of life assessment, and duplex ultrasound evaluation were performed at 2 days and after 1, 3, 6, and 12 months.ResultsIn 70 patients, of whom 68 (97.1%) were available for 1…
Hybrid methacrylate monolithic columns containing magnetic nanoparticles for capillary electrochromatography
2015
Abstract Vinylized iron oxide magnetic nanoparticles (VMNPs) were incorporated into polymethacrylate monolithic columns to develop novel stationary phases with enhanced separation performance. The VMNPs were dispersed in a polymerization mixture containing gycidyl methacrylate and ethylene glycol dimethacrylate as monomers, cyclohexanol and 1-dodecanol as porogens and azobisisobutyronitrile as initiator. The stability of the VMNPs in the polymerization mixture was investigated at several VMNP contents. Using short UV-polymerization times, polymeric beds with homogenously dispersed VMNPs were obtained. The novel stationary phases were characterized by scanning electron microscopy. The chroma…
Cytotoxic effect of silorane and methacrylate based composites on the human dental pulp stem cells and fibroblasts
2014
Objectives: The aim of this study was to compare the cytotoxic effect of a methacrylate-based and a silorane- based composite on the human dental pulp stem cells (DPSCs) versus human dental pulp fibroblasts (DPFs). Study Design: Samples of the Filtek Z250 and P90 were polymerized and immersed in the culture medium to obtain extracts after incubation for one, seven and 14 days. Magnetic cell sorting based on the CD146 expression was performed to purify DPSCs and DPFs. After incubation of both cells with the extracts, cytotoxicity was de - termined using the MTT test. Results: For the extracts of first and seventh day, both composites showed significantly lower cytotoxicity on DPSCs than DPFs…
Electrophoretic flow behaviour and mobility of colloidal fluids and crystals.
2007
We report on measurements of the electrophoretic mobility mu of charged colloidal spheres in the deionized state, where the suspensions show fluid or crystalline order. In the fluid state, parabolic flow profiles are observed due to electro-osmotic solvent flow. In the crystalline state, complex flow profiles occur due to additional crystal cohesion. The mobility mu then may inferred from the flow velocity averaged over the complete cell cross section as performed in our home built super-heterodyne Doppler velocimeter. For two particle species of 68 and 122 nm diameter we measured mu as a function of particle concentration. Starting from a plateau value at low concentration, mu decreases ap…