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Biomedical subjects

M M Rhemrev-Boom

Publications and source records attributed to M M Rhemrev-Boom.

3 recordsLinked to original sources

(Immuno)affinity chromatography: a versatile tool for fast and selective purification, concentration, isolation and analysis.

Today, thanks to the availability of tailor made biomolecules with the desired biological functions, separations based upon (immuno)affinity techniques are more and more common in a large field of applications. By using the high selectivity of biomolecules (antibodies, receptors, specific proteins), this technique offers the possibility of isolating compounds from complex samples with a selectivity which cannot be achieved by other chromatographic methods. In order to succeed, however, the solid phase support for the immobilisation of the ligand of interest plays a prominent role. For this reason, numerous supports have already been introduced while research on new materials with additional advantages is continued. Here, a new solid phase support will be discussed for (immuno)affinity applications. This material demonstrates low non-specific adsorption and high ligand accessibility, which enables an enhanced selectivity and capacity. Because the material is available in large quantities and exhibits superb mechanical and physical stability, selective isolations have been performed on analytical as well as preparative scale. To demonstrate the potential of this new support, several applications will be presented. Based upon immunoaffinity, two applications for the determination of oestradiol in serum respectively vitamin B12 in fermentation broth will be presented. Regarding affinity chromatography, an enzyme reactor in which the enzyme glucose oxidase is immobilised on the new material, is made for the detection of glucose by Flow Injection Analysis and electrochemical detection. Next, to isolate, identify and test components on their xeno-oestrogenic activity, an affinity column is produced in which human oestrogen receptor is covalently coupled. Several components are screened on their biological activity and the results obtained will be presented here.

Chromatography, Affinity↗

A versatile biosensor device for continuous biomedical monitoring.

Although biosensors are by means suitable for continuous biomedical monitoring, due to fouling and blood clotting, in vivo performance is far from optimal. For this reason, ultrafiltration, microdialysis or open tubular flow is frequently used as interface. To secure quantitative recoveries of the analyte of interest, sampling at submicrolitre level will be necessary which in turn necessitates the development of small and versatile biosensor devices. Here, a miniaturised biosensor device, which directly can be connected to various interfaces will be presented. The biosensor device consists of a pulsefree pump and a biosensor with an internal volume of 10-20 nl. In this article, the production as well as the construction of the flow-through cell of the biosensor will be discussed. The advantages and disadvantages of several production processes will be demonstrated and a detailed protocol for the production of such a nanoliter flow-through cell will be presented. With respect to the bio-selector, several permselective membranes have been tested on their performance characteristics. Results obtained with these biosensors will be presented and discussed. Finally, a protocol based upon in situ electropolymerisation for the immobilisation of the biological component was defined and several biosensors based upon this principle have been produced and tested for the monitoring of glucose respectively lactate. To demonstrate, data obtained during a variety of in vivo studies at different clinical relevant applications will be presented.

Animals↗

On-line continuous monitoring of glucose or lactate by ultraslow microdialysis combined with a flow-through nanoliter biosensor based on poly(m-phenylenediamine) ultra-thin polymer membrane as enzyme electrode.

A miniaturised flow-through biosensor with a cell volume of only a few nanoliters was developed in our laboratory. The biosensor can be directly coupled to a microdialysis or ultrafiltration probe. Sampling and continuous on-line monitoring can thus be carried out at submicroliter levels and as a consequence quantitative recoveries of the analyte of interest are achieved. Via this method excessive calibration procedures, as are necessary with conventional microdialysis, are avoided. Here, the construction and the performance of such a biosensor for the continuous on-line monitoring of glucose and lactate will be presented. The biosensor is based on the amperometric detection of hydrogen peroxide after conversion of the analyte of interest by an immobilised oxidoreductase enzyme. Immobilisation of the enzyme is performed through electropolymerisation of m-phenylenediamine. Strategies to improve the performance (e.g. linearity, selectivity and stability) of the miniaturised biosensor are discussed and ex vivo and in vivo experiments carried out thus far demonstrate the potential of this miniaturised flow-through biosensor.

Biosensing Techniques↗