Covalent immobilization of antibody fragments on well-defined polymer brushes via site-directed method.

Well-defined polymer brushes and block copolymer brushes consisting of 2-methacryloyloxyethyl phosphorylcholine (MPC) and glycidyl methacrylate (GMA) were prepared by surface-initiated atom transfer radical polymerization (ATRP). The polymer brushes were used for the immobilization of antibody fragments in a defined orientation. Pyridyl disulfide moieties were introduced to the polymer brushes via a reaction of epoxy groups in GMA units. Fab' fragments were then immobilized onto these surfaces via a thiol-disulfide interchange reaction and the reactivity of antibodies with antigens was investigated. Antigen/antibody binding on the polymer brushes was more preferable than that on epoxysilane films as a control surface. Furthermore, the activity of the antibodies immobilized on the block copolymer brushes having biocompatible PMPC was greater than that on other surfaces that did not have PMPC in their structures.