Light-Induced Remodeling of Physically Crosslinked Hydrogels Using Near-IR Wavelengths.

Poly([6-bromo-7-hydroxycoumarin-4-yl]methyl methacrylate)-based triblock copolymers were synthesized by first preparing PMAA-PEG-PMAA triblocks using ATRP. 6-Bromo-4-chloromethyl-7-hydroxycoumarin was conjugated to PMAA-PEG-PMAA using 1,8-diazabicycloundec-7-ene (DBU). Rheological measurements were conducted using a HR-2 rheometer with a UV illumination accessory (TA Instruments). Single-photon uncaging was performed as previously described.20 Two-photon uncaging was performed using a LSM (Zeiss) equipped with a Ti: Sapphire laser (Coherent). All values reported as mean ± std. dev. unless otherwise stated. See Supporting Information for experimental details.