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.

Blended Chitosan Paste for Infection Prevention: Preliminary and Preclinical Evaluations

“…The chitosan/PEG hydrogel literature has reported acceptable biocompatibility [14,25,26]. The results found from this testing performed on chitosan/PEG pastes are comparable to the various reported chitosan hydrogels [8,17,24].…”

Biodegradable Inorganic–Organic POSS–PEG Hybrid Hydrogels as Scaffolds for Tissue Engineering

“…The prepolymers were mixed by vortexing before transferred to mold for gelation at 37 °C. The gelation time was determined as the time when the hydrogels would no longer flow by the force of gravity …”

Recent Progress on the Design and Applications of Polysaccharide‐Based Graft Copolymer Hydrogels as Adsorbents for Wastewater Purification

“…The molecular structures of the most common monomers and crosslinking agents, such as AA, MAA, AAM, acrylonitrile (AN), AAM derivatives, divinyl benzene, gluteraldehyde, and MBA, used in the preparation of hydrogels are given in Figure . The graft copolymers of different gum polysaccharides, such as gum xanthan, gum ghatti, guar gum, chitosan, etc., with different vinyl monomers have been reported to have potential applications in drug delivery, flocculation, and wastewater treatment …”