title: Synthesis of photoresponsive hybrid alginate hydrogel with photo-controlled release behavior.
abstract: A photoresponsive hybrid alginate hydrogel was successfully prepared by Ca(2+)-mediated crosslinking reaction with a mixture of β-cyclodextrin-grafted alginate (β-CD-Alg) and diazobenzene-modified poly(ethylene glycol) (Az2-PEG). The water-soluble Az2-PEG exhibits efficient trans-to-cis isomerization of the terminal azobenzene moieties under UV-light irradiation and readily switched back to the initial trans state under visible light. Because of low affinity between β-CD and cis-Az, the host-guest inclusion complex formed by β-CD and trans-Az gradually dissociates under UV-light exposure. Accordingly, the bulk gel exhibits substantial photo-induced transformation in gel morphology by the appearance of significant comb-like cavities. This photosensitive behavior accompanied by the structural degradation enables the rapid release of entrapped dye molecules under UV light stimulus. Moreover, an incident light with higher power and mild acidic environment are capable of accelerating the photo-triggered release, thus allowing the potential applications toward acute wound healing.
authors.affiliation: School of Medical Applied Chemistry, Chung Shan Medical University, Taichung 40201, Taiwan.
authors.forename: Chien-Ying
authors.initials: CY
authors.lastname: Chiang
authors.affiliation: School of Medical Applied Chemistry, Chung Shan Medical University, Taichung 40201, Taiwan; Department of Medical Education, Chung Shan Medical University Hospital, Taichung 40201, Taiwan. Electronic address: jrchu@csmu.edu.tw.
authors.forename: Chih-Chien
authors.initials: CC
authors.lastname: Chu
mesh_terms: D000464:Alginates / Q000138:chemical synthesis* / Q000737:chemistry; D003692:Delayed-Action Preparations; D020723:Glucuronic Acid / Q000138:chemical synthesis / Q000737:chemistry; D006603:Hexuronic Acids / Q000138:chemical synthesis / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D014466:Ultraviolet Rays; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D000464:Alginates; D003692:Delayed-Action Preparations; D006603:Hexuronic Acids; D012235:Rhodamines; D047392:beta-Cyclodextrins; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D020723:Glucuronic Acid; C031215:betadex; C029773:rhodamine B
keywords: Alginate; Azobenzene; Hydrogel; Photoisomerization; Wound dressing