By Sophie Bushwick
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They’re called hydogels: Jell-O-like materials made of networks of long-chain molecules in water. And they’re as flexible as living tissue. But hydrogels could not recover from a cut—until now. Bioengineers at U.C. San Diego have made hydrogels that are self-healing in acidic conditions.
When you cut open a piece of hydrogel, the polymers that normally entwine to hold the gel together cannot grasp each another again, leaving the wound unhealed. But in the new gels, additional molecular chains dangle from the primary structure. When two pieces of the cut hydrogel are pressed together in an acidic solution, the side chains of each piece tangle up to weld the parts together. The work is in the Proceedings of the National Academy of Sciences. [Ameya Phadke et al., "Rapid self-healing hydrogels"]
These hydrogels could seal up industrial acid leakages and contribute to self-healing plastics. In the acidic environment of the stomach, they could bandage holes or deliver drugs to ulcers. The researchers are trying to make gels that mend at a range of pH levels. They may look like desserts, but self-healing hydrogels could be a medical main course.