The present invention provides a method of suppressing inflammation and promoting repair of an injured neural tissue in a subject in need thereof, including administering to the injured neural tissue an effective amount of a carboxyl-functionalized polyurethane nanoparticle. The method of the present invention significantly suppresses immune responses by inhibiting pro-inflammatory cytokine production and facilitates neurological recovery, and thus it may be applied directly in patients going through neurosurgery.
