title: Lysozyme loading and release from hydrogels carrying pendant phosphate groups.
abstract: To develop a polymeric matrix for efficiently loading cationic biomolecules, polyelectrolyte hydrogels carrying pendant phosphate groups were synthesized by copolymerizing 2-methacryloyloxyethyl dihydrogen phosphate with N-isopropylacrylamide and N, N1-methylene-bis-acrylamide. The phosphate-carrying monomer yielded anionic hydrogels, which formed ionic complexes with the cationic protein, lysozyme. It was shown that the amount of complexed lysozyme reached 2.1 g g-1 dry gel, corresponding to 1.3 x 10(-3) mol phosphate group per gram lysozyme, when 40 mol% of phosphate-carrying monomer was incorporated in a hydrogel. When the hydrogel complexed with lysozyme was placed in deionized water and various KCl solutions, of varying concentrations of up to 0.5 M KCl, no lysozyme was released in deionized water, while increasing amounts of lysozyme were released as the KCl concentration increased. This confirmed that lysozyme was loaded in the hydrogel through electrostatic interactions. It was further found that the complexed lysozyme retained its enzymatic activity after being released from the hydrogel. These results suggest the use of this system for the controlled release of cationic protein drugs.
authors.affiliation: Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakamae
authors.forename: T
authors.initials: T
authors.lastname: Nizuka
authors.forename: T
authors.initials: T
authors.lastname: Miyata
authors.forename: M
authors.initials: M
authors.lastname: Furukawa
authors.forename: T
authors.initials: T
authors.lastname: Nishino
authors.forename: K
authors.initials: K
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: A S
authors.initials: AS
authors.lastname: Hoffman
authors.forename: Y
authors.initials: Y
authors.lastname: Kanzaki
mesh_terms: D001672:Biocompatible Materials; D004800:Enzymes, Immobilized / Q000378:metabolism; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D009113:Muramidase / Q000378:metabolism; D009994:Osmolar Concentration; D010710:Phosphates / Q000138:chemical synthesis; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids / Q000138:chemical synthesis; D011485:Protein Binding
chemical_list: D001672:Biocompatible Materials; D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D010710:Phosphates; D011109:Polymethacrylic Acids; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D009113:Muramidase