A liquid plasma expander or resuscitation fluid composition for use in a subject in need thereof, comprising, consisting of, or consisting essentially of: (a) a keratin derivative (preferably alpha keratose, gamma keratose, or combinations thereof, and with basic alpha keratose preferred over acidic alpha keratose); and (b) an electrolyte solution, with the keratin derivative solubilized in the electrolyte solution to form a homogeneous liquid composition. Blood substitutes formed therefrom and methods of making and using the same are also described.