Surface modification method and surface modification body

A method for surface-modifying an object made of a thermoplastic resin, wherein the object is a matrix, filter, channel, or tube configured for medical or healthcare use and for contact with blood or biological fluids and wherein the thermoplastic resin is polyethylene terephthalate or polystyrene, the method comprising:

• a step 1 of forming polymerization initiation points on a surface of the object, wherein said step 1 comprises adsorbing a photopolymerization initiator to the surface of the object to form the polymerization initiation points from the photopolymerization initiator on the surface;
• and
• a step 2 of radically polymerizing an alkoxyalkyl (meth)acrylate hydrophilic monomer starting from the polymerization initiation points by irradiation with UV light having a wavelength of 300 to 400 nm to grow polymer chains on the surface of the object,
• wherein the photopolymerization initiator is a benzophenone compound;
• wherein the hydrophilic monomer is a 2-methoxyethyl acrylate monomer;
• wherein during or before the irradiation, an inert gas is inserted into a reaction vessel, a reaction tube, and a reaction solution, and the hydrophilic monomer is polymerized in an atmosphere replaced with the inert gas;
• wherein the radical polymerization of the hydrophilic monomer in the step 2 is carried out by applying or spraying a solution of the hydrophilic monomer onto the surface of the object, and then covering the applied or sprayed object with a transparent cover of glass or resin, followed by the irradiation with the UV light through the transparent cover of glass or resin to radically polymerize the hydrophilic monomer;
• wherein the surface of the surface-modified object has reduced protein adsorption ranging from 0.13-0.34 μg/cm2 of bovine serum albumin as compared to the unmodified surface of the object;
• wherein the polymer chains each have a length of 800 to 3000 nm.