title: Nanoporous sorbent material as an oral phosphate binder and for aqueous phosphate, chromate, and arsenate removal.
abstract: Phosphate removal is both biologically and environmentally important. Biologically, hyperphosphatemia is a critical condition in end-stage chronic kidney disease patients. Patients with hyperphosphatemia are treated long-term with oral phosphate binders to prevent phosphate absorption to the body by capturing phosphate in the gastrointestinal (GI) tract followed by fecal excretion. Environmentally, phosphate levels in natural water resources must be regulated according to limits set forth by the US Environmental Protection Agency. By utilizing nanotechnology and ligand design, we developed a new material to overcome limitations of traditional sorbent materials such as low phosphate binding capacity, slow binding kinetics, and negative interference by other anions. A phosphate binder based on iron-ethylenediamine on nanoporous silica (Fe-EDA-SAMMS) has been optimized for substrates and Fe(III) deposition methods. The Fe-EDA-SAMMS material had a 4-fold increase in phosphate binding capacity and a broader operating pH window compared to other reports. The material had a faster phosphate binding rate and was significantly less affected by other anions than Sevelamer HCl, the gold standard oral phosphate binder, and AG® 1-X8, a commercially available anion exchanger. It had less cytotoxicity to Caco-2 cells than lanthanum carbonate, another prescribed oral phosphate binder. The Fe-EDA-SAMMS also had high capacity for arsenate and chromate, two of the most toxic anions in natural water.
authors.affiliation: Department of Biomedical Engineering, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
authors.forename: Thanapon
authors.initials: T
authors.lastname: Sangvanich
authors.affiliation: Department of Biomedical Engineering, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
authors.forename: Worapol
authors.initials: W
authors.lastname: Ngamcherdtrakul
authors.affiliation: Department of Biomedical Engineering, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
authors.forename: Jingga
authors.initials: J
authors.lastname: Morry
authors.affiliation: Department of Biomedical Engineering, Oregon Health & Science University (OHSU), Portland, Oregon, USA ; PDX Pharmaceuticals, LLC, Lake Oswego, Oregon.
authors.forename: David
authors.initials: D
authors.lastname: Castro
authors.affiliation: Battelle Distinguished Inventor, Kennewick, Washington, USA.
authors.forename: Glen E
authors.initials: GE
authors.lastname: Fryxell
authors.affiliation: Department of Biomedical Engineering, Oregon Health & Science University (OHSU), Portland, Oregon, USA ; PDX Pharmaceuticals, LLC, Lake Oswego, Oregon.
authors.forename: Wassana
authors.initials: W
authors.lastname: Yantasee
keywords: arsenate; chromate; hyperphosphatemia; mesoporous silica; oral phosphate binder; phosphate; sorbent