ISSN:0920-5063    

DOI:10.1163/156856292X00231

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Radio frequency plasma-deposited thin films offer an advantageous mechanism to alter the surface properties of biomaterials and medical devices without affecting the mechanical properties or primary fabrication. Such coatings are tightly adherent, conformal, and easily applied. They also exhibit excellent biocompatibility qualities. Examples are presented of four different thin film plasma treatments that show promise for reducing the platelet reactivity of materials, enhancing their ability to grow cells, preventing protein pickup by surfaces, and improving the biocompatibility of opthalmic devices.

ISSN:0920-5063    

DOI:10.1163/156856292X00240

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Polysiloxane films were prepared by plasma polymerization and dip coating. Upon these films PEG was grafted by conventional methods, and ethylene oxide by plasma activation. Before and after grafting the films were analyzed by contact angle and ESCA measurements as well as by FTIR-ATRspectroscopy and TOF-SIMS. Furthermore results of protein adsorption measurements are reported. The polysiloxane structures obtained by the plasma polymerization of HMDSO are rather similar to those ones yielded by dip coating. The two types of grafting applied on the polysiloxane substrates led to different structures of the grafted layers as was revealed by TOF-SIMS spectra.

ISSN:0920-5063    

DOI:10.1163/156856292X00259

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Five different plasma modified surfaces were made for studying different aspects of biocompatibility. These surfaces were: 1,2-diaminocyclohexane (DACH), acrylic acid (AA), Hydroxyethylmethacrylate (HEMA), methane and hexamethylene-disiloxane (HMDSO). In addition a polyethylene-glycol (PEG) was made by grafting aldehyde functional PEG to the DACH surface. PEG and HMDSO which are the most hydrophilic and the most hydrophobic surface shows the lowest amount of adsorbed protein of the three proteins studied here (albumin, IgG and C3). Methane, HMDSO and HEMA was found to activate via the classical (complement activation) pathway while the others activated via the alternative pathway.

ISSN:0920-5063    

DOI:10.1163/156856292X00268

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

By applying an argon plasma treatment to a layer of a surface active agent pre-adsorbed on a polymer substrate, it is possible to covalently couple this layer to the substrate. This method offers a direct route to tailor the surface properties of polymers.

ISSN:0920-5063    

DOI:10.1163/156856292X00277

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Tetrafluoroethylene (TFE) glow discharge-treated Dacron vascular grafts resist thrombus deposition, embolization and thrombotic occlusion. In addition, albumin adsorbed on TFE-treated surfaces resists elution by sodium dodecyl sulfate (SDS). Since the tight binding of albumin to TFE-treated surfaces may contribute to their thromboresistant character, we decided to examine the mechanism responsible for this tenacious adsorption. We have investigated albumin adsorption and retention (after SDS elution) on a number of untreated and glow discharge-treated surfaces. Fluorocarbon glow discharge-treated polymers retain a larger fraction of the adsorbed albumin than ethylene and hexamethyldisiloxane glow discharge-treated surfaces. Albumin retention by surfaces appears to be closely related to their surface free energy (in air). Low energy surfaces (in air), whether untreated or glow discharge-treated, retain a larger fraction of the albumin adsorbed than higher energy surfaces. The lowest energy surfaces should have the highest interfacial energies in water, with correspondingly high driving forces for adsorption of proteins. This can lead to the formation of multiple binding sites upon adsorption, permitting strong hydrophobic interactions, which leads to the observed strong binding.

ISSN:0920-5063    

DOI:10.1163/156856292X00286

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Surface properties of biomaterials can easily be modified by glow-discharge plasma processing for very diverse biomedical appliations. Activated carbon granules can be coated with a very thin polymeric membrane by plasma polymerization to improve their blood compatibilities without changing their adsorption capabilities. The problems associated with the microporous polypropylene oxygenator membranes can be eliminated by coating with a nonporous thin polymeric film in a glow-discharge reactor. Cell attachment and growth on polystyrene microcarriers can significantly be increased by alkylamine plasma treatment. Physical and chemical properties of polyurethane biomaterials can be tailor-made by plasma modification.

ISSN:0920-5063    

DOI:10.1163/156856292X00295

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The chemical composition and the reactivity of films deposited in RF glow discharges fed with Ar-tetramethylsilane and Ar-tetramethylsilane-O2mixtures have been studied by X-ray photoelectron spectroscopy. The analyses have been performed by means of a spectrometer connected in vacuo to the deposition reactor. This configuration allows to analyze as deposited films without any external contamination of oxygen and moisture. The work has been conducted by studying the detailed Si2p, Cls, and Ols signals at different electron take-off angles, as well as the valence band region. Depth profiling of films by means of Ar+ion sputtering has also been performed in some cases.

ISSN:0920-5063    

DOI:10.1163/156856292X00303

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor