Preparation Of Novel Chitosan Resins And Their Adsorption Properties For Bilirubin

The hemoperfusion is a ubiquitously adjusted and lower cost method for blood purification. The adsorption ability of the adsorbents for hemoperfusion is the essential factor for the effect of blood purification. Chitosan is a kind of abundant natural macromolecule compounds, which has lots of predominant performance. This compound is nontoxic, biocompatible and easy to be modified, thus the biopolymer has great potential to be used as macromolecular adsorbent. The type and character of blood purification and the recent development of polymeric adsorbents for hemoperfusion were summarized in this paper. Three novel chitosan adsorbents were prepared. The adsorption properties for bilirubin and bile acid of the adsorbents wereinvestigated.The main experiments and conclusions of this paper were described as follows:(1) A novel aminated chitosan resin was prepared by chitosan Schiff base intermediate, through hydroxypropyl-chloridization and animation. The adsorption properties of the aminated chitosan resin were investigated. The results showed that the amine-group content for the novel aminated chitosan resin was improved compared with chitosan. The adsorption capacity for dissociated bilirubin was increased with the increment of the amine-group content and related to the adsorption temperature and the ion strength. The adsorption capacity of the resin for combined bilirubin is larger than that of chitosan.(2) A series of quaternary ammonium chitosan resins with different degree of crosslink and different degree of substitute were prepared using chitosan and 2,3-epoxypropyl trimethylammonium chloride. The structure and surface morphology were characterized by FT-IR and SEM analysis and the adsorption properties of the resins were investigated. The results showed that the adsorption capacity of resin for dissociated bilirubin was increased with the increment of the degree of substitute in the case of the higher degree of crosslink. The adsorption capacity of 84%DS resin for bilirubin is five times than that of 0%DS resin. In the same DS, the adsorption capacity for bilirubin was increased with the decrease of the degree of crosslink(3) The microsphere of quaternary ammonium chitosan was synthesized. The structure and surface morphology of these microspheres were characterized by FT-IR and SEM analysis and the adsorption properties of the resins were investigated. The results showed that the adsorption capacity for bile acid of the quaternary ammonium chitosan microsphere is much better than that of the crosslinked chitosan microsphere. Adsorption equilibrium for bilirubin was arrived in 3 hours. Adsorption equilibrium for bile acid was arrived in 5 hours. Absorbed bile acid could be entirely wiped off by NaCl solution. The adsorption capacity of resin did not change after resin was used repeatedly for 6 times.