title: Molecular recognition-based detoxification of aluminum in human plasma.
abstract: Molecular recognition-based Al(3+)-imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-glutamic acid) (PHEMAGA-Al(3+)) beads were prepared to be used in selective removal of Al(3+) out of human plasma overdosed with Al(3+) cations. The PHEMAGA-Al(3+) beads were synthesized by suspension polymerization in the presence of a template-monomer complex (MAGA-Al(3+)). The specific surface area of PHEMAGA-Al(3+) beads was found to be 55.6 m(2)/g on the average. The MAGA content in the PHEMAGA-Al(3+) beads were found to be 640 micgomol/g polymer. The template Al(3+) cations could be reversibly detached from the matrix to form PHEMAGA-Al(3+) using a 50 mM solution of EDTA. The Al(3+)-free PHEMAGA-Al(3+) beads were then exposed to a selective separation procedure of Al(3+) out of human plasma, which was implemented in a continuous system by packing the beads into a separation column (10 cm long with an inner diameter of 0.9 cm) equipped with a water jacket to control the temperature. The Al(3+) adsorption capacity of the PHEMAGA-Al(3+) beads decreased drastically from 0.76 mg/g polymer to 0.22 mg/g polymer as the flow rate was increased from 0.3 ml/min to 1.5 ml/min. The relative selectivity coefficients of the PHEMAGA-Al(3+) beads for Al(3+)/Fe(3+), Al(3+)/Cu(2+) and Al(3+)/Zn(2+) were found to be 4.49, 8.95 and 32.44 times greater than those of the non-imprinted PHEMAGA beads, respectively. FT-IR analyses on the synthesized PHEMAGA-Al(3+) beads reveals monodentate and bidentate binding modes of Al(3+) in complex with the carboxylate groups of the glutamate residues. Density functional theory computations at the B3LYP/6-31G(d,p) basis set suggests that structured water molecules play essential role in the stability of the monodentate binding mode in 1:1 PHEMAGA-Al(3+) complexes. The PHEMAGA-Al(3+) beads were recovered and reused many times, with no significant decrease in their adsorption capacities.
authors.affiliation: Department of Chemistry, Biochemistry Subdivision, Hacettepe University, Ankara, Turkey.
authors.forename: Ahmet H
authors.initials: AH
authors.lastname: Demircelik
authors.forename: Muge
authors.initials: M
authors.lastname: Andac
authors.forename: Cenk A
authors.initials: CA
authors.lastname: Andac
authors.forename: Ridvan
authors.initials: R
authors.lastname: Say
authors.forename: Adil
authors.initials: A
authors.lastname: Denizli
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000737:chemistry / Q000302:isolation & purification*; D018698:Glutamic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D054802:Molecular Imprinting; D010949:Plasma / Q000737:chemistry*; D016062:Porosity; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D016060:Sorption Detoxification / Q000379:methods*; D013499:Surface Properties
chemical_list: D008689:Methacrylates; C115674:N-methacryloyl-glutamic acid; D018698:Glutamic Acid; C005044:hydroxyethyl methacrylate; D000535:Aluminum