Hydrogels with Reversible Mechanics to Probe Dynamic Cell Microenvironments

Stiffening hydrogels to probe short- and long-term cellular responses to dynamic mechanics.

Biological processes are dynamic in nature, and growing evidence suggests that matrix stiffening is particularly decisive during development, wound healing and disease; yet, nearly all in vitro models are static. Here we introduce a step-wise approach, addition then light-mediated crosslinking, to fabricate hydrogels that stiffen (for example, ~3-30 kPa) in the presence of cells, and investigat...

Protein-patterned hydrogels: Customized cell microenvironments.

Designing degradable hydrogels for orthogonal control of cell microenvironments

Degradable and cell-compatible hydrogels can be designed to mimic the physical and biochemical characteristics of native extracellular matrices and provide tunability of degradation rates and related properties under physiological conditions. Hence, such hydrogels are finding widespread application in many bioengineering fields, including controlled bioactive molecule delivery, cell encapsulati...

Reversible Ag(+)-crosslinked DNA hydrogels.

DNA hydrogels, consisting of Y-shaped nucleic acid subunits or of nucleic acid-functionalized acrylamide chains, undergo switchable gel-to-solution transitions. The Ag(+)-stimulated formation of cytosine-Ag(+)-cytosine complexes results in the crosslinking of the units to yield the hydrogels, while the cysteamine-induced elimination of the Ag(+) ions dissociates the hydrogels into a solution ph...

Mechanics of Reversible Unzipping

We study the mechanics of a reversible decohesion (unzipping) of an elastic layer subjected to quasi-static end-point loading. At the micro level the system is simulated by an elastic chain of particles interacting with a rigid foundation through breakable springs. Such system can be viewed as prototypical for the description of a wide range of phenomena from peeling of polymeric tapes, to roll...