Preparation of Hexanediamine-contained PAMAM Dendrimers Supported on Chitosan Microspheres and Their Application in the Adsorption of Bilirubin

Glutaraldehyde cross-linked chitosan microspheres(CS) were prepared by inverse phase suspension reaction.Low generations(Gn,n≤3) hexanediamine-contained PAMAM dendrimers were supported to chitosan microspheres.Bilirubin adsorption on the above microspheres was carried out in 0.05 mol/L phosphate buffer solution(pH=7.2-7.4) at 37 ℃.The results show that the equilibrium adsorption percentage of CS-G2.0,CS-G3.0,CS-G1.0,CS-G0 and CS microspheres are 94.61%,93.44%,92.97%,86.47% and 52.38%,respectively.The adsorption percentage of CS-G1.0-CS-G3.0 microspheres is over 70% at 0.5 h and arrived to the equilibrium at about 1 h.The adsorption capacity is up to 42.78 mg/g.All the moderations(CS-G0-CS-G3.0) are much better than CS microspheres for bilirubin adsorption.The effects of temperature,pH,bilirubin initial concentration,ion strength and bovine serum albumin(BSA) on the adsorption properties for bilirubin were studied.It was shown that adsorption percentage increased at higher temperature.Adsorption properties were the best at near neutral solutions of pH≈7.PAMAM dendrimers supported in chitosan microspheres had satisfactory competitive abilities with BSA for bilirubin adsorption though adsorption percentage decreaed to a certain extent in the presence of BSA.