摘要 |
A solid surface having anionic groups capable of reacting with imino groups is provided with a hydrophilic outer surface layer comprising a covalently bonded biopolymer by a method selected from the group consisting of: a) reacting a water-soluble conjugate comprising nonionic hydrophilic polymer covalently bonded to a polyethylene imine and at least partly to a biopolymer with anionic groups on the surface; b) reacting a polyethylene imine substituted by nonionic hydrophilic polymer with anionic groups on the surface, and reacting biopolymer with reactive groups of the nonionic hydrophilic polymer in the presence of a reaction medium having a dielectric constant less than 10% of the dielectric constant of pure water; and c) reacting a polyethylene imine substituted by an anionic hydrophilic polymer derived from a nonionic hydrophilic polymer having a cloud point which is at least 5 DEG C. above the temperature at which the final product is to be used, and having biopolymer-reactive groups, and reacting biopolymer forming covalent bonds with reactive groups of the nonionic polymer in a water-base reaction medium at a temperature which is more than 5 DEG C. below the cloud point of the nonionic hydrophilic polymer in the reaction medium. The product comprises a biopolymer immobilized on a hydrophilic solid surface having a hydrophilic layer, coupled thereto via a polyethylene imine, and accordingly has low spontaneous adsorption of proteins and other biopolymers through electrostatic attraction and/or hydrophobic interaction. |