Engineering of new crosslinked functional PEG micrometer-sized particles of narrow size distribution for enzyme immobilization

New functional crosslinked poly(ethylene glycol) (PEG) micrometer-sized particles of narrow size distribution were prepared by dispersion co-polymerization in an aqueous continuous phase of the monomers methacrylate polyethylene glycol carboxylic acid (MA-PEG-COOH) or methacrylate polyethylene glycol amine (MA-PEG-NH2) with polyethylene glycol methacrylate ether (MA-PEG-OCH3) and the crosslinker monomer polyethylene glycol dimethacrylate (PEDMA). The effect of various polymerization parameters, e.g., total monomer concentration, crosslinker monomer concentration, initiator concentration and stabilizer concentration and Mw on the size, size distribution and polymerization yield of the produced particles has been studied. As a model for enzyme immobilization, trypsin was covalently bound to the functional PEG particles. A substantial loss in the activity and an increase in the stability of the conjugated enzyme, as compared to the free one, were demonstrated.