Spotlight on hydrogels

Kristi Anseth and colleagues have made an important advance in dynamic hydrogel design to help them reconstruct functional biological tissues in a culture dish. They were able to modulate biophysical and biochemical gel properties dynamically and locally using photolabile building blocks that can be cleaved by a controlled light beam. This novel approach to hydrogel design should be particularly appealing for fields such as developmental biology, stem-cell biology or tumor-cell biology, in which the role of the microenvironment in controlling cell function. Other groups have designed biomimetic gels that degrade in a natural fashion, by using building blocks that are sensitive to cell-secreted enzymes that break down proteins, with the aim of mimicking the dynamic character of the extracellular matrix (ECM) during remodeling.