Innovation in materials development and characterization has been and continues to be foundational in the Anseth group. For example, photoinitiated thiol-ene crosslinking of hydrogels, which was developed to enable facile incorporation of extracellular matrix mimetic peptides into synthetic poly(ethylene glycol) hydrogels with precise spatio-temporal control over the polymerization reaction, is now widely used in our group to study topics like cell migration and directed differentiation of stem/progenitor cells.
To further expand our capabilities and enable the design of powerful new biological experiments, a current theme in the materials group is the development of photo-responsive hydrogels to allow for user-controlled manipulation of the cellular microenvironment. Building off of prior work with photodegradable nitrobenzyl ether crosslinked hydrogels, we have recently developed diverse photo-responsive material platforms that allow for dynamic changes in hydrogel modulus, controlled presentation of topographic cues, as well as on demand release of proteins from nano- and micro-particles. In addition, by implementing cytocompatible "click" reactions for hydrogel crosslinking (e.g., strain promoted azide-alkyne cycoladdition) in concert with orthogonal photolabile and photocoupling chemistries we have shown that it is possible to sequentially introduce and remove biochemical and biophyiscal signals with precise spatio-temporal control. While we now have a number of tools at our disposal for engineering photo-responsive hydrogels, we are continuing to work to expand the toolbox by exploring alternative click reactions and photochemistries.
In addition to our work on photo-responsive hydrogels, a second focus with the materials group is the development of techniques to characterize and understand changes in the cellular microenvironment. Current topics of interest include the application of multiple particle tracking microrheology to characterize changes in the hydrogel network during cell migration and the development of fluorescent probes to monitor cellular activity (e.g., matrix metalloproteinase expression) in real time.