University of California Researchers develop gel to cure wounds that don't heal easily

As ageing populations and rising diabetes rates fuel a surge in chronic wounds, a growing number of patients face the threat of amputation. Researchers at the University of California Riverside have developed an oxygen-delivering gel designed to heal injuries that might otherwise lead to limb loss.

Wounds that do not heal within a month are classified as chronic. Globally, they affect an estimated 12 million people each year, including about 4.5 million in the United States. Roughly one in five of these patients ultimately undergoes amputation.

The newly developed gel, tested in animal models, addresses what scientists identify as a primary driver of chronic wounds: insufficient oxygen in the deepest layers of damaged tissue. Without adequate oxygen, wounds remain trapped in prolonged inflammation, creating conditions where bacteria thrive and tissue breaks down instead of repairing itself.

“Chronic wounds don’t heal by themselves,” said Iman Noshadi, associate professor of bioengineering at UC Riverside and lead author of the study. He explained that healing involves four stages—inflammation, vascularisation (formation of new blood vessels), remodelling, and regeneration—and that a steady oxygen supply is critical at every phase.

When oxygen from the air or bloodstream fails to reach deep tissue, hypoxia occurs, disrupting the natural healing process. The team’s oxygen-delivery strategy is detailed in a study published in Nature Communications Materials.

The soft, flexible gel contains water and a choline-based liquid that is antibacterial, non-toxic, and biocompatible. When connected to a small battery similar to those used in hearing aids, the gel functions as a miniature electrochemical system, splitting water molecules to produce a slow and continuous flow of oxygen.

Unlike conventional treatments that supply oxygen only at the surface, this gel adapts to the wound’s unique shape, penetrating crevices where oxygen deprivation and infection risk are greatest. Before solidifying, it precisely conforms to the contours of the injured tissue.

Crucially, the oxygen release is sustained rather than intermittent. Since vascularisation can take weeks, short bursts of oxygen are insufficient. The system can maintain therapeutic oxygen levels for up to a month, helping convert a nonhealing wound into one that progresses like a typical injury.

In experiments involving diabetic and older mice—whose wounds closely resemble chronic wounds in ageing humans—untreated injuries failed to close and often proved fatal. With the oxygen-generating patch applied and replaced weekly, wounds healed in approximately 23 days, significantly improving survival outcomes.