Search results for "Methylmethacrylate"
showing 10 items of 14 documents
Characterization of the Epithelial Permeation Enhancing Effect of Basic Butylated Methacrylate Copolymer—In Vitro Studies
2008
Membrane destabilizing properties and increased efflux of doxorubicin from liposomes caused by basic butylated methacrylate copolymer (BBMC), better known under its commercial trade name EUDRAGIT E, have been described in the scientific literature. Here, we investigated the effect of BBMC on suspended and filter-grown Caco2 cells with respect to apical-to-basal transport and membrane permeabilization using transport assays, trypan blue exclusion assay, measurements of transepithelial electrical resistance (TEER), confocal laser scanning microscopy, and transmission electron microscopy. The effect of inhibiting protein phosphatase 2A (PP2A) by okadaic acid was investigated by measuring TEER,…
mRNA-induction and cytokine release during in vitro exposure of human nasal respiratory epithelia to methyl methacrylate
2007
Abstract Background Methyl methacrylate (MMA) has been reported to cause histopathological changes in rodent nasal epithelium after inhalation challenges. Data in humans are lacking. Methods In this in vitro design 22 primary cell cultures taken from inferior turbinate tissue of healthy individuals were exposed to MMA concentrations of 50 ppm (German MAK-value) and 200 ppm. mRNA expression and cytokine release of inflammatory mediators were quantified after 4 h and after 24 h. Controls were exposed to synthetic air. Q-PCR analysis was performed for TNF-α, IL-1β, IL-6, IL-8, MCP-1, GMCSF, Cox-1 and Cox-2. ELISA assays were performed from culture supernatants for TNF-α, IL-1β, IL-6, IL-8, MCP…
Novel Biodegradable Composite of Calcium Phosphate Cement and the Collagen I Mimetic P-15 for Pedicle Screw Augmentation in Osteoporotic Bone
2021
Osteoporotic vertebral fractures often necessitate fusion surgery, with high rates of implant failure. We present a novel bioactive composite of calcium phosphate cement (CPC) and the collagen I mimetic P-15 for pedicle screw augmentation in osteoporotic bone. Methods involved expression analysis of osteogenesis-related genes during osteoblastic differentiation by RT-PCR and immunostaining of osteopontin and Ca2+ deposits. Untreated and decalcified sheep vertebrae were utilized for linear pullout testing of pedicle screws. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DEXA). Expression of ALPI II (p <
Evaluation of 2,3-epoxypropyl groups and functionalization yield in glycidyl methacrylate monoliths using gas chromatography
2014
Abstract Poly(glycidyl methacrylate- co -ethylene dimethacrylate) (poly(GMA- co -EDMA)) is most frequently used as parent monolith to obtain stationary phases with a variety of surface chemistries for liquid chromatography and capillary electrochromatography. Functionalization is performed by opening the accessible 2,3-epoxypropyl groups of the monolith with a suitable reagent. The number of 2,3-epoxypropyl groups which are accessible before and after the functionalization reaction, and the grafting yield, are important parameters, required both to optimize functionalization and to interpret the chromatographic performance of functionalized monoliths. In this work, a method capable of provi…
Polymethacrylate monoliths with immobilized poly-3-mercaptopropyl methylsiloxane film for high-coverage surface functionalization by thiol-ene click …
2014
In this work, new polythiol-functionalized macroporous monolithic polymethacrylate-polysiloxane composite materials are presented which can be useful substrates for highly efficient immobilization of (chiral) catalysts, chromatographic ligands, and other functional moieties by thiol-ene click reaction. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) (poly(GMA-co-EDMA)) monoliths were coated with a poly-3-mercaptopropyl methylsiloxane (PMPMS) film and subsequently the polymer was covalently immobilized by formation of crosslinks via nucleophilic substitution reaction with pendent 2,3-epoxypropyl groups on the monolith surface. This monolith, though, showed similar levels of surface co…
Interactions of lysozyme with hydrophilic and hydrophobic polymethacrylate stationary phases in reversed phase chromatography (RPC)
1994
Two silicas, one with a mean pore diameter of 30 nm and the other non-porous, were coated with polymethacrylates of increasing hydrophobicity in the sequence: poly-2-hydroxyethylmethacrylate (P2HEMA)1 polyethylmethacrylate (PEMA) and poly-n-octylmethacrylate (POMA). Association constants, Kass, between lysozyme and the coated silicas were determined by means of frontal analysis, and the apparent heats of adsorption, delta Happ, by means of microcalorimetry. Using Kass and delta Happ the changes in the apparent free energy, delta Gapp, and in the apparent entropy, delta Sapp, were calculated at a concentration of lysozyme < 10 mumol/l. The association between the lysozyme and the coated sili…
Pharmacokinetics of methylmethacrylate monomer during total hip replacement in man.
1988
The concentration of methylmethacrylate monomer (MMA) in the blood stream after implantation of the components of 15 total hip prostheses using bone cement was determined in the pulmonary artery, the radial artery, and the superior vena cava after cement application, and correlated with the observed drop in blood pressure and the increase in the pulmonary arterial pressure. In all samples MMA was found. The values ranged from 0.02 micrograms/ml to 59 micrograms/ml. The mean maximum value after implantation of the stem was measured to be 7.8 micrograms/ml in the pulmonary artery, 4.6 micrograms/ml in the radial artery, and 1.75 micrograms/ml in the superior vena cava. After implantation of t…
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…
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…
Temperature Sensor Based on Colloidal Quantum Dots PMMA Nanocomposite Waveguides
2012
In this paper, integrated temperature sensors based on active nanocomposite planar waveguides are presented. The nanocomposites consist of cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) embedded in a polymethylmethacrylate (PMMA) matrix. When the samples are heated in a temperature range from 25$^{circ}{rm C}$ to 50 $^{circ}{rm C}$, the waveguided photoluminescence of QDs suffers from a strong intensity decrease, which is approximately quadratic dependent on temperature. Moreover, the wavelength peak of the waveguided emission spectrum of CdTe-PMMA shows a blue shift of 0.25 ${rm nm}/^{circ}{rm C}$, whereas it remains constant in the case of CdSe-PMMA. A temperature…