silicon and glycidyl-methacrylate

Zwitterionic copolymers keep good resistance to platelet adhesion and nonspecific protein adsorption. In this study, A block copolymer brushes consisting of carboxybetaine methacrylate (CBMA) and glycidyl methacrylate (GMA) were grafted from silicon wafers via surface-initiated atom transfer radical polymerization, and then the Arg-Glu-Asp-Val (REDV) peptide was attached to the polymer brush via an reactive epoxy group of the P(GMA) unit to improve endothelial cells (ECs) selectivity. These modified surfaces were evaluated with scanning electron microscopy, atomic force microscopy, attenuated total reflectance-Fourier transform infrared spectra, X-ray photoelectron spectroscopy, and static water contact angle measurement. The results showed that REDV-modified zwitterionic brushes were successfully constructed on silicon wafers. The biocompatibility of the membrane was determined by plasma recalcification time assay and platelet adhesion test. The results showed that the modified substrate exhibited good blood compatibility. Moreover, the proliferation of ECs and smooth muscle cells onto the REDV-modified copolymer brushes were examined to demonstrate the synergistic effect of CBMA with antifouling property and REDV peptide with ECs selectivity. All assays showed that the silicon wafers displayed excellent EC selectivity after modification. In summary, REDV-modified zwitterionic brushes had great potential for cardiovascular stent implantation.

Topics: Adsorption; Amino Acid Sequence; Animals; Biocompatible Materials; Biofouling; Cell Proliferation; Endothelial Cells; Epoxy Compounds; Materials Testing; Methacrylates; Oligopeptides; Platelet Adhesiveness; Polymerization; Polymers; Rabbits; Silicon; Surface Properties

Polymeric coatings, usually referred as tridimensional chemistries, provide homogenous surface derivatization methods presenting a high reactive group concentration and resulting in an increased binding capacity of targets. Furthermore, they act as linkers distributing the bound probe also in the axial position, thus causing a faster reaction with the target involved in biomolecular recognition and can be engineered to custom tailor their properties for specific applications. Most approaches which aim at attaching polymers to a surface use a system where the polymer carries an "anchor" group either as an end group or in a side chain. This anchor group can reacts with appropriate sites at the substrate surface, thus yielding surface-attached monolayers of polymer molecules (termed "grafting to"). Another technique is to carry out a polymerization reaction in the presence of a substrate onto which monomers had been attached leading to the so called "grafting from" approach. In this chapter, protocols to functionalize glass and silicon surfaces by "grafting to" as well as by "grafting-from" approach are shown using copolymers made of N,N-dimethylacrylamide (DMA) or Glycidyl methacrylate (GMA) as the polymer backbone, N-acryloyloxysuccinimide (NAS) as reactive group, and 3-(trimethoxysilyl)propyl methacrylate (MAPS) or 3-mercaptopropyl trimethoxy silane (MPS) as anchoring groups.

Topics: Acrylamides; Biocompatible Materials; Biotechnology; Epoxy Compounds; Glass; Methacrylates; Polymerization; Polymers; Silicon; Surface Properties

Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for "click" chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using "click" chemistry, and grafting densities in the range of 0.007-0.95 chains nm(-2) were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm(-3). The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.

Topics: Alkynes; Click Chemistry; Epoxy Compounds; Methacrylates; Polymethacrylic Acids; Silicon; Surface Properties

Well-defined polymer brushes and block copolymer brushes consisting of 2-methacryloyloxyethyl phosphorylcholine (MPC) and glycidyl methacrylate (GMA) were prepared by surface-initiated atom transfer radical polymerization (ATRP). The polymer brushes were used for the immobilization of antibody fragments in a defined orientation. Pyridyl disulfide moieties were introduced to the polymer brushes via a reaction of epoxy groups in GMA units. Fab' fragments were then immobilized onto these surfaces via a thiol-disulfide interchange reaction and the reactivity of antibodies with antigens was investigated. Antigen/antibody binding on the polymer brushes was more preferable than that on epoxysilane films as a control surface. Furthermore, the activity of the antibodies immobilized on the block copolymer brushes having biocompatible PMPC was greater than that on other surfaces that did not have PMPC in their structures.

Topics: Algorithms; Antigens; Biocompatible Materials; Epoxy Compounds; Immunoglobulin Fab Fragments; Immunoglobulin Fragments; Methacrylates; Polymers; Silicon; Spectrometry, X-Ray Emission; Surface Properties

Controlled grafting of well-defined epoxide polymer brushes on the hydrogen-terminated Si(100) substrates (Si-H substrates) was carried out via the surface-initiated atom-transfer radical polymerization (ATRP) at room temperature. Thus, glycidyl methacrylate (GMA) polymer brushes were prepared by ATRP from the alpha-bromoester functionalized Si-H surface. Kinetic studies revealed a linear increase in GMA polymer (PGMA) film thickness with reaction time, indicating that chain growth from the surface was a controlled "living" process. The graft polymerization proceeded more rapidly in the dimethylformamide/water (DMF/H(2)O) mixed solvent medium than in DMF, leading to much thicker PGMA growth on the silicon surface in the former medium. The chemical composition of the GMA graft-polymerized silicon (Si-g-PGMA) surfaces were characterized by X-ray photoelectron spectroscopy (XPS). The fact that the epoxide functional groups of the grafted PGMA were preserved quantitatively was revealed in the reaction with ethylenediamine. The "living" character of the PGMA chain end was further ascertained by the subsequent growth of a poly(pentafluorostyrene) (PFS) block from the Si-g-PGMA surface, using the PGMA brushes as the macroinitiators.

Topics: Epoxy Compounds; Hydrogen; Methacrylates; Particle Size; Polymers; Polystyrenes; Silicon; Surface Properties; Temperature