Immobilization of protein streptavidin to the surface of polymer polystyrene (PS) was studied. Two different protocols were used to attach streptavidin to the PS surface: physical adsorption and chemical coupling. In both cases the surface properties of PS samples were modified by exposure to cold oxygen plasma. Oxygen plasma treatment caused formation of O-rich functional groups on the surface of PS. The concentration of oxygen was determined by XPS (X-ray photoelectron spectroscopy) and was about 28 at.%. A thin film of streptavidin was deposited by physical adsorption and chemical bonding. The appearance of streptavidin on the surface was determined from XPS spectra measuring the ratio between N and C peaks. The plasma treatment caused poor adsorption and but strong chemisorption of streptavidin. The results were explained by specific interaction of protein with polar functional groups on the surface of PS after plasma treatment.
COBISS.SI-ID: 25718823
In this paper we describe a new method for the synthesis of magnetic liposomes with incorporated magnetic nanoparticles of iron oxide. The size of magnetic liposomes can be independently controlled by varying the intensity and frequency of electric field. The size of liposomes was increasing with increasing frequency and intensity of electric field, as well as with increasing time of electroformation.
COBISS.SI-ID: 25304103
In this paper we have presented a new method for the synthesis of metal-oxide nanoparticles. Nanoparticles are synthesized on the surface of a metal by using low-pressure nonequilibrium and highly reactive oxygen plasma. Plasma is a rich source of oxygen atoms, which react with the surface of the sample. Because of nonequilibrium situation in plasma, localized growth of metallic oxide nanoparticles occurs on the surface of the metal. The method is extremely fast and efficient. Nanoparticles are formed already in few seconds of treatment.
COBISS.SI-ID: 24140071
We have shown an example of the use of oxygen plasma for controlled surface modification of polymer material, which is widely used in medical applications. By non-equilibrium oxygen plasma we can influence the surface morphology, wetting behaviour, adhesion properties of the surface and formation of new functional groups on the surface. This functional groups act as binding sites for further attachment of proteins like streptavidin. The procedure is therefore suitable for improving the biocompatibility of polymer surfaces to which we can link proteins or other bioactive molecules.
COBISS.SI-ID: 23927335
In this contribution we have shown that polymer surface is saturated with oxygen functional groups already in a very short time of plasma treatment. Among them especially important are carboxyl groups, which are needed for further binding of the protein streptavidin. We have shown that by combination of plasma treatment and chemical coupling of protein streptavidin with the help of EDC reagent (1-ethyl-3-(3-dimethylaminopropyl) we can achieve very stable binding of protein to the surface of the substrate, while the physical adsorption itself was not so promising. Stable binding of protein to the plasma treated polymer surface can be achieved only with the chemisorption.
COBISS.SI-ID: 24973095