however is that the column may be loaded with a series of such foams each containing a different bioreactant in this way a series of discrete biochemical operations can be conducted in a particular order as the blood passes through the column thereby closely simulating the function of a vital organ in addition of course bioreactants which would otherwise be incompatible in the same solution can be safely incorporated into the same column by the use of such discrete foams it is very frequently desirable to combine the bioreactant gel with a broad spectrum solid adsorbent in order that toxic substances including waste metabolites or reaction products not sequestered by the bioreactant may be removed at the same time the solid adsorbent substrate material could be any of various conventional adsorbents such as activated carbon alumina and the like this is a common necessity where severely ill patients have multiple organ failure and other diverse abnormalities in this application the superior porosity and transport characteristics of the bioreactant gel are distinctly important because the toxic substance may well be attached to a very large carrier such as a protein which could not penetrate ordinary small pore hydrogels in order to assure that the bioreactant remains active it must not be permitted to penetrate the recesses of the adsorbent prior to the target reactive event indeed the bioreactant used in this example deferoxamine mesylate becomes completely inactivated when adsorbed losing entirely its ability to chelate metals in order to prevent premature adsorption of the bioreactant it is therefore necessary to introduce a competitively adsorbed solvent into the monomer bioreactant mixture along with the other ingredients.