The Preparation Of The Membrane For Adsorption And The Adsorption Performance Of Bilirubin Were Filtered In One Step

Hemoperfusion is an important treatment for the removal of albumin-bound toxins in the blood.Preparation of adsorbents with good blood compatibility has always been a hot spot and a difficulty in correlated research.In clinical treatment,plasma separation coupled with plasma perfusion or protein dialysis method are used to remove the pathogenic substances in the blood.That would avoid blood cells contacting with blood adsorption materials,so blood compatibility is indirectly improved while the treatment costs are greatly increased.In this paper,the one-step filtration adsorption method was designed,which innovatively combined with adsorption material preparation and adsorption method design.During this process,the blood cells were intercepted by the porous membrane,while the plasma protein and pathogenic substances penetrated the membranes under certain pressure.Then the penetrated pathogenic substances were adsorbed by the adsorption layer in the outer surface of the membrane and the pure plasma protein flowed back into the blood.In this way,blood cells in the blood were trapped by the porous membrane and do not come into contact with the adsorbent on the permeate side of the membrane,reducing the requirements of adsorbent blood compatibility.In this paper,hydrophobic PVDF membrane was used as the matrix material to explore the program of ?-cyclodextrin(?-CD)grafted to the membrane surface,so three experimental schemes were designed.The first method was realized by the directly nucleophilic substitution reaction between the amine on the membrane surface and 6-O-p-to,luenesulfonyl-?-CD;the second method was realized by the reaction between the carboxyl group grafted on the ?-CD and the amine group on the surface of the membrane;The third method was realized by amidation reaction of aminated ?-CD with the aminated PVDF membrane surface which has been further carboxylated.The results of the experiment were characterized by thin layer chromatography,Fourier Transform Infrared Spectroscopy(FTIR),nuclear magnetic resonance,element analysis and X-ray photoelectron spectroscopy.The results show that the third method succeeded in grafting ?-CD onto the surface of PVDF membrane and was more conducive to the P-CD grafting onto the surface of PVDF membrane.Therefore,bilirubin is considered as a typical pathogenic substances in the blood to verify the one-step filtration adsorption.PVDF hollow plasma membrane was used as matrix material,and the monosubstituted ?-CD was used as the adsorptive ligand for bilirubin removal,which was grafted only on the permeate side of the membrane.Then the modified membrane was used to demonstrate the feasibility of the one-step filtration adsorption for removing bilirubin.Compared with the direct adsorption method,the adsorption amount of bilirubin was decreased slightly by 5%,the adsorption capacity reached 10.7?g/cm2,and adsorption rate reached 41.2%in the one-step filtration adsorption.These could prove it had good bilirubin adsorption ability.Next the competitive adsorption coefficient with protein was more than 2,which showed it had competitive adsorption capacity with albumin.Then the adsorption test of bovine serum albumin showed that the outer side of the membrane had low adsorption capacity,the adsorption rate was only about 3.0%,which was conducive to the flow-back of albumin.Finally the hemolysis experiments and blood cell adsorption experiments were used to characterize the blood compatibility of the membrane,the results showed that the modification process increased adverse effect on cells and so decreased its blood compatibility.However one-step filtration adsorption could improve its blood compatibility.Therefore,this study provided a new idea for the removal of pathogenic substances in the blood,and a combination of good albumin-bound toxins adsorption performance and great blood compatibility through reduced operation procedures was achieved.