Brain edema: changes in brain water content. The changes in brain water content of polyHb-SOD-CAT–treated animals are not significantly different from those of animals in the sham control group. The increases in water contents of animals treated with saline, SF-Hb, SF-Hb + SOD + CAT, and polyHb were significantly higher than those of animals in the sham control group and the polyHb-SOD-CAT group by the fourth hour and continued to increase thereafter. Statistical significance is P<.01. (From Chang TMS. Artificial cells: biotechnology, nanotechnology, blood substitutes, regenerative medicine, bioencapsulation. Singapore: World Scientific Publishing Co., 2007; with permission.)