Search results for "Methacrylates"
showing 10 items of 88 documents
New biodegradable hydrogels based on a photocrosslinkable modified polyaspartamide: synthesis and characterization
1999
Abstract α,β-Poly( N -2-hydroxyethyl)- dl -aspartamide (PHEA), a synthetic water-soluble biocompatible polymer, was derivatized with glycidyl methacrylate (GMA), in order to introduce in its structure chemical residues having double bonds and ester groups. The obtained copolymer (PHG) contained 29 mol% of GMA residues. PHG aqueous solutions at various concentrations ranging from 30 to 70 mg/ml were exposed to a source of UV rays at λ 254 nm in the presence or in the absence of N , N ′-methylenebisacrylamide (BIS); the formation of compact gel phases was observed beginning from 50 mg/ml. The obtained networks were characterized by FT-IR spectrophotometry and swelling measurements which evide…
In syringe hybrid monoliths modified with gold nanoparticles for selective extraction of glutathione in biological fluids prior to its determination …
2020
Abstract In this work, a simple device for extraction glutathione (GSH) in biological fluids using a hybrid monolithic material within a polypropylene syringe is developed. For this purpose, glycidyl methacrylate-based monolith was firstly prepared within this housing material, and the polymer was modified with different ligands (ammonia, cysteamine and cystamine). The resulting materials (containing amine or thiol groups, respectively) were then functionalized with gold nanoparticles (AuNPs). The hybrid material that gave the largest AuNPs coverage was selected as solid-phase (SPE) sorbent and several variables affecting the extraction recovery of this compound were investigated. Under opt…
Extraction of β-blockers from urine with a polymeric monolith modified with 1-allyl-3-methylimidazolium chloride in spin column format
2020
Abstract A glycidyl methacrylate-based monolith was modified with imidazolium-based ionic liquid (IL) to be used as stationary phase for solid-phase extraction (SPE). The host monolithic support was prepared by in-situ UV polymerization in spin column format. Two approaches were developed to incorporate the IL into the polymeric monolithic matrix: generation of IL onto the surface monolith, and copolymerization by addition of the IL to the polymerization mixture, which gave the best results. The resulting sorbent materials were morphologically characterized and used for the isolation of five β-blockers from human urine samples. All SPE steps were accomplished by centrifugation, which reduce…
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…
From Defined Reactive Diblock Copolymers to Functional HPMA-Based Self-Assembled Nanoaggregates
2008
This paper describes the synthesis of functional amphiphilic poly( N-(2-hydroxypropyl) methacrylamide)-block-poly(lauryl methacrylate) copolymers by RAFT polymerization via the intermediate step of activated ester block copolymers (pentafluoro-phenyl methacrylate). Block copolymers with molecular weights from 12000-28000 g/mol and PDIs of about 1.2 have been obtained. The amphiphilic diblock copolymers form stable super structures (nanoaggregates) by self-organization in aqueous solution. The diameters of these particles are between 100 and 200 nm and depend directly on the molecular weight of the block copolymer. Furthermore, we investigated the impact of these nanoaggregates on cell viabi…
Preparation and evaluation of lauryl methacrylate monoliths with embedded silver nanoparticles for capillary electrochromatography
2012
In this article, capillary columns constituted by lauryl methacrylate monoliths with embedded silver nanoparticles (AgNPs) were developed and tested. Two incorporation approaches of AgNPs in monoliths were explored. The AgNPs were either photogenerated in situ during polymerization of the monolith by UV irradiation, or incorporated to the polymerization mixture (ex situ). The influence of the AgNP concentration on the morphological and chromatographic properties of the polymer matrix was investigated, and both the in situ and ex situ approaches were comparatively discussed. The morphology of the monoliths was characterized by electron microscopic techniques, and their electrochromatographic…
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…
Solvent for removing silicone oil from intraocular lenses: experimental study comparing various biomaterials.
2000
Abstract Purpose To evaluate the effectiveness of a perfluorocarbon—perfluorohexyloctane (PFHO)—in removing silicone oil from different intraocular lenses (IOLs) and determine whether any removal technique enhances the removal of silicone oil. Methods Six IOL materials were analyzed: standard poly(methyl methacrylate) (PMMA), heparin-surface-modified (HSM) PMMA, AcrySof, 2 polyHEMAs with different water contents, and a second-generation SLM-2 silicone. One or 2 μL of a highly viscous silicone oil (5700 cs) was applied to the center of each IOL optic. Perfluorohexyloctane (2 mL) was then used to remove the silicone oil by 1 of 3 techniques: immersion of the IOL in PFHO; irrigation of the sil…
Cationic Nanohydrogel Particles for Therapeutic Oligonucleotide Delivery.
2017
Short pharmaceutical active oligonucleotides such as small interfering RNA (siRNA) or cytidine-phosphate-guanosine (CpG) are considered as powerful therapeutic alternatives, especially to medicate hard-to-treat diseases (e.g., liver fibrosis or cancer). Unfortunately, these molecules are equipped with poor pharmacokinetic properties that prevent them from translation. Well-defined nanosized carriers can provide opportunities to optimize their delivery and guide them to their site of action. Among several concepts, this Feature Article focuses on cationic nanohydrogel particles as a universal delivery system for small anionic molecules including siRNA and CpG. Cationic nanohydrogels are deri…
Synthesis and In Vitro Evaluation of Defined HPMA Folate Conjugates: Influence of Aggregation on Folate Receptor (FR) Mediated Cellular Uptake
2010
In this article we report the synthesis and in vitro evaluation of well-defined, folate functionalized and fluorescently labeled polymers based on the clinically approved N-(2-hydroxypropyl)-methacrylamide (HPMA). The polymers were prepared applying the RAFT polymerization method as well as the reactive ester approach. The molecular weights of the polymers synthesized were around 15 and 30 kDa. The total content of conjugated folate varied from 0, 5, and 10 mol %. The cellular uptake of these polymers was investigated in the folate receptor (FR)-positive human nasopharyngeal epidermal carcinoma (KB-3-1) and FR-negative human lung epithelial carcinoma (A549) cancer cell lines. In FR-positive…