A bactericidal polymeric composition includes a hydrophilic first comonomer copolymerized to a second comonomer to produce a polymeric composition that is more hydrophilic or more bactericidal in an aqueous solution than either of the comonomers alone. Methods for identifying bactericidal polymers, methods for rendering materials bactericidal, and methods for using bactericidal compositions to kill or reduce bacterial growth are also described. Applications for the inventive compositions include their use in catheters, stents, medical devices, contact lenses; root canal fillers; and/or wound dressings.