New types of microspheres and microsphere-related materials for medical diagnostics

Polymer microspheres are used in diagnostics as "reagents" and as elements of diagnostic devices. In this paper we compare properties of microspheres with aldehyde, carboxyl and hydroxyl groups in their surface layers. Microspheres with aldehyde groups were obtained by radical emulsion copolymerization of styrene and acrolein and in sequential redox polymerization of pyrrole followed with radical polymerization of acrolein. Microspheres with hydroxyl groups were synthesized by radical emulsion copolymerization of styrene and alpha-t-butoxy-omega-vinylbenzyl-polyglycidol macromonomer. Microspheres with hydroxyl and carboxyl groups were synthesized by radical emulsion copolymerization of methylmethacrylate, acrylic acid and 2-hydroxyethylmethacrylate. X-Ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) revealed that microspheres had the core-shell morphology with surface layers enriched in polymeric units with reactive groups. The above mentioned microspheres were used as supports for adsorption and covalent immobilization of human and animal proteins-human serum albumin (HSA), gamma globulins (gammaG; human, rabbit and goat), human fibrinogen (Fb), and enzymes: glucose oxidase (GOD) and urease (Urs). The applicability of microspheres with attached antigens and/or antibodies (gammaG) for turbidimetric aggregation tests and for a new type of test based on changes of electrophoretic mobility of microspheres is discussed. Potential applications of microspheres with immobilized enzymes for the construction of biosensors are described. Copyright (C) 2003 John Wiley Sons, Ltd.