{Reference Type}: Journal Article
{Title}: Photoresponsive Gelation of Four-Armed Poly(ethylene glycol) with Photodimerizable Groups.
{Author}: Okihara M;Okuma K;Kawamura A;Miyata T;
{Journal}: Gels
{Volume}: 8
{Issue}: 3
{Year}: Mar 2022 16
{Factor}: 4.432
{DOI}: 10.3390/gels8030183
{Abstract}: 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.