Chelsea Kirschner publishes a nice review of dynamic hydrogel environments titled "Hydrogels in Healthcare: From Static to Dynamic Microenvironments" in Acta Materialia. She summarized current progress in light, enxyme, electric field, temperature, and pH sensitive hydrogels for biomedical applications.
C.M. Kirschner and K.S. Anseth, " Hydrogels in Healthcare: From Static to Dynamic Material Microenvironments," Acta Materialia, 61, 931-944 (2013).