Investigations on the adsorbents for uremic middle molecular toxins (II) -Influences of crosslinking agent chain length on the adsorption capacitiesof crosslinked chitosan adsorbents

Chitosan resins, which clinically served as adsorbents in hemoperfusion the rapy, were prepared with reversed-phase suspension methodology using three differently structured crosslinking agents, methanal, glyoxal and glutarald ehyde. And the glyoxal and glutaraldehyde crosslinked chitosan resins were reduced with NaBH4 afterwards. By analyzing the results from FTIR and SEM, it was found that the reduction treatment to the adsorbents efficiently imp roved the chemical stability of these chitosan resins, and the shifts in cr osslinking agents exerted influences over the morphologies of the adsorbent s obviously., After being put to use in the adsorption tests upon some mode l uremic middle molecular toxins and BSA in vitro, all three adsorbents dem onstrated a fairly realistic adsorption capability,to the model toxins but little to BSA. And the adsorption process reached the equilibrium in a clin ically qualified short time. But the adsorption capacities of these adsorbe nts; to the model toxins were quite different. It had been found that with the growing of fatty chain length of crosslinking agent, these adsorbents s howed a gradually increased adsorption capacity to the model toxins, and th e glutaraldehyde crosslinked chitosan resin behaved best.