POLYACROLEIN CONTAINING MICROSPHERES - SYNTHESIS, PROPERTIES AND POSSIBLE MEDICAL APPLICATIONS

Polymeric microspheres are used in medical diagnostics, therapy, and a s supports for enzymes and other proteins in biotechnology. These part icles have also found application in fundamental studies in the life-s ciences as useful tools for separation of the living cells and subcell ular fragments. This article presents comprehensive information on pol yacrolein containing microspheres suitable for medical applications. V arious synthetic procedures (radical, anionic, and red-ox polymerizati ons) are described, leading to polyacrolein microspheres, microspheres made of polyacrolein and other polymers, and copolymer microspheres c ontaining polyacrolein segments. These particles can be obtained in a range of diameters from ca. 50 nm to a few micrometers, often with ver y narrow diameter distributions. Depending on the particular synthetic routes, it is possible to obtain microspheres with a uniform structur es, core-shell, and raspberry morphologies. In this review, methods us ed for the characterization of the chemical structure of the surface l ayer of microspheres, in particular, methods used for determination of reactive (aldehyde) groups are also discussed. Results of studies on the immobilization of proteins onto polyacrolein containing microspher es, including relationships between the mode of protein binding (coval ent immobilization and physical adsorption) and the fraction of polyac rolein in the surface layer of microspheres are reviewed. Methods allo wing one to obtain protein-microsphere systems in which the attached p roteins retain a substantial part of their biological activity are des cribed. Polyacrolein containing microspheres, after attachment of sele cted antibodies, can be used as reagents in diagnostic tests. There ar e examples of using these particles for the fabrication of new materia ls for hemoperfusion columns and for the formation of two-dimensional particle assemblies on surfaces of polyethylene, quartz, and glass, wh ich are potentially useful for the fabrication of biosensors.