The present invention is directed to a method of making a stable composition comprising growth factors, which may include platelet derived growth factors and transforming growth factors. The method comprises providing human umbilical cord blood plasma containing platelets, but substantially free of whole blood cells, and lysing the platelets to extrude growth factors into the plasma. The plasma may be obtained from multiple donors and pooled to form a homologous plasma mixture. In another embodiment, the growth factors are encapsulated in a liposome formed by a lipid bilayer, wherein the resulting composition remains stable and viable for at least 30 months. The present invention is also directed to the composition produced by the methods of the present invention and the process of applying the composition to a skin defect or wound.
