%0 Journal Article
%T Photoresponsive Gelation of Four-Armed Poly(ethylene glycol) with Photodimerizable Groups.
%A Okihara M
%A Okuma K
%A Kawamura A
%A Miyata T
%J Gels
%V 8
%N 3
%D Mar 2022 16
%M 35323296
%F 4.432
%R 10.3390/gels8030183
%X Standard hydrogels prepared by free radical polymerization (FRP) have heterogeneous structures with a wide mesh size distribution, which affect their mechanical and separation properties. Recent research has identified four-armed poly(ethylene glycol) (tetra-PEG) as a solution to this problem. tetra-PEG gels with a homogeneous network can be prepared and applied as high-strength gels and cell-culture substrates by reacting two types of tetra-PEG with different reactive groups at the ends. In this study, we report a photoresponsive tetra-PEG that undergoes a phase transition from a sol to a gel state in response to light. tetra-PEGs containing cinnamoyl and maleimide groups at the ends of the four-armed chains were found to gel when exposed to light. The effects of polymer concentration and light irradiation time on the gelation of tetra-PEG containing photodimerization groups were investigated. The results showed that the elastic modulus of the gel increased with the increase in the light irradiation time.