Left: PolyHb formed by nanobiotechnological assembling of Hb molecules into soluble nanodimension complex. Right: PolyHb-CAT-SOD formed by nanobiotechnological assembling of Hb, CAT, and SOD into soluble nanodimension complex. (From Chang TMS. Artificial cells: biotechnology, nanotechnology, blood substitutes, regenerative medicine, bioencapsulation. Singapore: World Scientific Publishing Co., 2007; with permission.)