Cysteine and pH-responsive hydrogel based on a saccharide derivative with an aldehyde group.
For the development of chemoresponsive hydrogel, a new saccharide-derived hydrogelator 1 [methyl-4,6-O-(4'-aldehydephenylidene)-alpha-D-glucopyranoside] was synthesized and characterized. The resulting hydrogel not only shows thermal responsiveness but also exhibits cysteine and pH responsiveness due to the presence of aldehyde and acetal groups in 1. The release of guest molecules from the hydrogel of 1 was examined by employing compound 2 (fluorescein disodium) and compound 3 [methyl-4,6-O-(2'-pyrenylidene)-alpha-D-glucopyranoside] as guest molecules. The results indicate that the release of compound 2 from the hydrogel of 1 is controlled by the diffusion process, while the release of compound 3 from the hydrogel of 1 is facilitated by the presence of cysteine. These results demonstrate (1) the proof of principle to design chemoresponsive gels by incorporating reactive groups into the gelators and (2) it is possible to stimulate the release of guest molecules from hydrogels upon addition of reactive chemicals by manipulating the intermolecular interactions among the hydrogelators and guest molecules.
Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Qun
Q
Chen
Yuxia
Y
Lv
Deqing
D
Zhang
Guanxin
G
Zhang
Chenyang
C
Liu
Daoben
D
Zhu
D003545:Cysteine / Q000737:chemistry*; D004548:Elasticity; D005960:Glucosides / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013050:Spectrometry, Fluorescence; D014783:Viscosity
D005960:Glucosides; C549264:methyl-4,6-O-(4'-aldehydephenylidene)-alpha-D-glucopyranoside; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D003545:Cysteine