New topical gel uses repurposed MS drug to heal burns

Researchers at the Terasaki Institute for Biomedical Innovation and the University of Arizona College of Medicine have developed a topical gel formulation with 4-aminopyridine (4-AP), to treat burn wounds, achieving near-complete closure in 21 days. The findings are published in the journal Biomaterials. 

Burn injuries rank among the most difficult wounds to heal. The current gold standard, transplanting skin from a donor site on the patient's own body, is limited by donor site morbidity and the need for large amounts of healthy tissue. This research offers a non-invasive alternative: a laponite-gelatin gel that delivers 4-AP directly to the wound, concentrating the drug where it is needed rather than exposing the whole body to it. Prolonged systemic use of 4-AP can cause serious side effects, including seizures, making localized delivery a critical advance. 

The drug is best known under the brand name Ampyra for treating multiple sclerosis. Earlier work showed it could influence keratinocytes and fibroblasts: the two cell types central to skin repair, but systemic administration carried unacceptable risks. Embedding it in a gel resolves that problem while preserving its therapeutic potential. 

By delivering 4-AP directly to the wound site, we harness its regenerative potential while avoiding the systemic risks that have limited its use. We believe this approach could meaningfully change how burn injuries are managed clinically."

Dr. Johnson V. John, Assistant Professor, Terasaki Institute for Biomedical Innovation 

Laboratory tests confirmed that the gel releases 4-AP at a controlled rate, is compatible with living cells, and produces more than 90 percent wound closure within 48 hours. In animal studies, treated wounds closed faster than controls starting at day six, reaching near-complete closure by day 21, while control wounds remained partially open. Tissue analysis showed the gel reduced inflammation, promoted re-epithelialization and angiogenesis, and drove fibroblast-to-myofibroblast transformation. Collagen deposition increased markedly by 438 percent for type I and 288 percent for type III versus controls (P < 0.05 to P < 0.0002), with an improved collagen ratio signaling better-quality tissue maturation. 

Because 4-AP is already FDA-approved with a well-characterized safety profile, this repurposing strategy could accelerate the path to clinical trials compared with developing an entirely new compound from scratch. 

"This research exemplifies our commitment to reimagining existing therapies to address medicine's most persistent challenges. We look forward to seeing it advance toward clinical application," stated Xiling Shen, Acting Director of the Terasaki Institute for Biomedical Innovation. 

This study represents a meaningful step forward in burn wound care, demonstrating that a well-established drug can be safely repurposed through simple and smart delivery technology to achieve outcomes that current treatments cannot. As the researchers move toward further preclinical and clinical evaluation, the 4-AP gel has the potential to offer burn patients a faster, less invasive path to recovery and to reduce the burden that severe burn injuries place on patients and healthcare systems alike.