Tough New Gel Mimics Part Of A Cell

Cells resist damage from everyday strain thanks in part to the materials in their cytoskeletons. These biopolymers stiffen when they are pulled. That quality is desirable for tissue engineering applications but has proved challenging to reproduce in a synthetic material. Now, chemists have come up with a polymer that responds to force much like the cytoskeleton’s biological scaffolding (Nature, DOI: 10.1038/nature11839). Alan E. Rowan and Paul H. J. Kouwer of Radboud University Nijmegen, in the Netherlands, led a team that modified polyisocyanopeptide polymers with triethylene glycol tails to control the materials’ solubility in water. The unusual polymers gelate when warmed—most gels form through cooling. In gel form, Rowan says, the polymer chains bundle together like fibers in a nanoscale rope, increasing the materials’ stiffness. Results from atomic force microscopy and rheology studies show that the polymer doesn’t snap under strain but instead stiffens like intermediate filaments, a component of the cytoskeleton. The team has patented the polyisocyanopeptides and has started a company called NovioTech to commercialize potential applications, including wound dressings.