Methods and compositions generating and using an interleukin-1 receptor antagonist (IL-1ra)-rich solution. Methods for generating and isolating interleukin-1 receptor antagonist include incubating a liquid volume of white blood cells and platelets with polyacrylamide beads to produce interleukin-1 receptor antagonist. The interleukin-1 receptor antagonist is isolated from the polyacrylamide beads to obtain the solution rich in interleukin-1 receptor antagonist. Methods for treating a site of inflammation in a patient include administering to the site of inflammation the solution rich in interleukin-1 receptor antagonist.