Immobilization of biologically active substances with a polyphosphazene

Abstract

A phosphazene polymer carrier is prepared that has functional groups capable of binding a biologically active substance such as an enzyme or antibody and groups which are non-reactive and hydrophilic. A bifunctional aldehyde is reacted with primary amino groups of a shaped phosphazene polymer to form side chains having aldehyde groups, an amino group-containing compound is reacted with a portion of the aldehyde groups to produce the groups that are non-reactive and hydrophilic, and aldehyde groups not reacted are capable of binding a biologically active substance. The phosphazene polymer may be crosslinked prior to reacting with the bifunctional aldehyde. In another embodiment, a protecting agent is reacted with a portion of the aldehyde groups to block the aldehyde groups, imino bonds are reduced, a compound having an amino group is reacted with aldehyde groups not blocked to form the groups which are non-reactive and hydrophilic, and the protecting agent is removed to provide aldehyde groups capable of binding a biologically active substance. The non-reactive and hydrophilic groups may also be formed by reacting primary amino groups with formaldehyde or by diazotizing primary amino groups of the polymer followed by hydrolysis to form hydroxyl groups. A biologically active substance immobilized on the polymer can be used to separate a substance that has affinity for the immobilized biologically active substance.