title: Chitosan-PEG hydrogel with sol-gel transition triggerable by multiple external stimuli.
abstract: Smart hydrogels play an increasingly important role in biomedical applications, since materials that are both biocompatible and multi-stimuli-responsive are highly desirable. A simple, organic solvent-free method is presented to synthesize a biocompatible hydrogel that undergoes a sol-gel transition in response to multiple stimuli. Methoxy-poly(ethylene glycol) (mPEG) is modified into carboxylic-acid-terminated-methoxy-poly(ethylene glycol) (mPEG-acid), which is then grafted onto chitosan via amide linkages yielding mPEG-g-chitosan. Grafting of mPEG onto hydrophobic chitosan imparts hydrophilic properties to the resultant polymer. The mPEG-g-chitosan gel exhibits a controllable multi-stimuli-responsive property. The balance between hydrophilicity and hydrophobicity is believed to confer mPEG-g-chitosan with stimuli-responsive behavior. The effect of salt concentration, solute concentration, temperature, and pH on the sol-gel transition of mPEG-g-chitosan is evaluated and the underlying mechanisms of mPEG-g-chitosan polymer packing and gelation property is discussed.
authors.affiliation: Department of Materials Science & Engineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Ching Ting
authors.initials: CT
authors.lastname: Tsao
authors.forename: Meng Hsuan
authors.initials: MH
authors.lastname: Hsiao
authors.forename: Mengying Y
authors.initials: MY
authors.lastname: Zhang
authors.forename: Sheeny Lan
authors.initials: SL
authors.lastname: Levengood
authors.forename: Miqin
authors.initials: M
authors.lastname: Zhang
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D020100:Hydrogels; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol; D048271:Chitosan
keywords: biocompatible; chitosan; hydrogels; poly(ethylene glycol); smart gels