Smart Wound Dressing Releases Healing Signals Only When Repair Cells Pull on It

Most wound treatments relying on growth factors operate by applying large amounts of manufactured proteins and hoping some reach the target cells. Much of the material degrades or disperses before it can act. Researchers at Imperial College London have developed an alternative approach that flips this model.

Their dressing contains no drugs. Instead, it captures growth factors naturally produced by the wound, retains them until repair cells arrive, and releases them only when those cells physically pull on the material. This mechanism has now been demonstrated in living tissue for the first time, as reported in Nature Materials in late July.

A Molecular Lock Triggered by Cellular Movement

The system relies on aptamers—short strands of nucleic acids folded into precise shapes that bind specific proteins. In this case, the aptamers attach to growth factors circulating in the wound, keeping them stable and preventing enzymatic breakdown.

As repair cells migrate into the wound site, they do not move smoothly. They grip their surroundings and contract, generating mechanical forces. When a repair cell pulls on an aptamer-bound growth factor, the interaction weakens and the cargo is released directly to that cell.

This design allows for selective activation. The researchers can adjust the system so that only mechanical forces characteristic of particular cell types unlock the payload. The goal is to deliver healing signals precisely to the cells responsible for tissue repair, at the exact moment they are engaged in the process. The method, termed traction-force-activated payloads, builds on chemistry first described by Ben Almquist’s team in 2019, inspired by how cells interacting with natural collagen structures activate embedded healing proteins. This latest study extends that concept to functional tissue repair models.

“What particularly stands out with this research is that the patient’s own body becomes the pharmacy,” said Almquist, associate professor of bioengineering and senior author, in an Imperial College announcement. He emphasized the design’s ability to capture endogenous proteins and redirect them to cells where they are needed.

Therapeutic Effects Seen at Vastly Reduced Doses

The platform achieves significant biological effects without the high doses typically associated with growth factor therapies.

Because the signals are delivered exactly where and when repair occurs, the treatment functions effectively at concentrations hundreds to thousands of times lower than standard approaches—and over 2,000 times lower than an existing clinical growth factor product.

This reduction carries major implications. High-dose regimens raise safety concerns, and lowering the required dose by several orders of magnitude significantly reduces risk. Additionally, the technology could potentially harvest growth factors directly from the patient’s own wound fluid or blood, removing reliance on laboratory-produced proteins entirely.

Growth factors guide essential healing processes such as cell migration, proliferation, blood vessel formation, and tissue regeneration. In chronic wounds, these signals are often insufficient, poorly timed, or rapidly degraded.

Validated in Rodent Models and Human Tissue

The researchers evaluated the dressing in multiple experimental systems, starting with rodent studies. Collagen sponges embedded with the platform enhanced blood vessel development in rats with bone injuries and accelerated closure of skin wounds in mice.

The most clinically relevant results emerged from studies on human tissue. Laboratory tests using living human skin showed improved repair outcomes, with visible migration of repair cells into the dressing material.

“What excites me most is that this works in living human skin. We can see repair cells migrating into the wound dressing and confirm the material is engaging with human biology,” said Magdalene Ho, lead author and researcher in Imperial’s Department of Bioengineering. Her findings suggest strong potential for future clinical applications.

The potential impact spans numerous conditions. Imperial College estimates that approximately 18.6 million people worldwide suffer from diabetic foot ulcers annually, with frequent complications. Burn and trauma-related injuries further expand the population that might benefit.

Bridging Laboratory Success to Clinical Reality

While promising, laboratory-grown human skin represents a step toward—but not equivalent to—clinical application. Explanted tissue lacks immune function, circulation, and the systemic factors that complicate chronic wounds in real-world settings.

Conditions like diabetic foot ulcers involve neuropathy, restricted blood flow, persistent infection, and chronic inflammation—not merely delayed cell migration. Demonstrating enhanced repair in healthy tissue does not guarantee efficacy against these deeper pathological drivers.

No clinical trials involving patients are currently underway. Regulatory approval and commercial availability remain distant goals. Additionally, many promising biomaterials have failed to outperform standard care once tested in clinical settings.

It is worth noting that the invention is being advanced through a startup company. Traxion Biotech, an Imperial College spinout founded by Ho, Almquist, and surgeon Shehan Hettiaratchy, holds the technology. The team is exploring partnerships to pursue clinical development. While this does not diminish the scientific merit, it indicates financial interest among the investigators.

Patients managing chronic wounds should maintain communication with healthcare providers. Those experiencing non-healing or infected wounds should seek medical evaluation rather than await experimental treatments.

Frequently Asked Questions

How does the dressing function? Aptamers capture naturally occurring growth factors in the wound. When repair cells migrate in and exert traction force, the aptamers release the growth factors directly to those cells.

How does this compare to traditional growth factor treatments? Conventional methods apply externally manufactured proteins, which degrade quickly and spread unevenly. Force-activated release delivers therapeutic molecules more efficiently at dramatically reduced doses.

In what models was the approach tested? Studies included rats with bone defects, mice with excisional skin wounds, and laboratory cultures of living human skin, all showing accelerated healing responses.

Is this treatment available now? No. The research remains in preclinical stages. No human trials or regulatory approvals have been initiated.

Which conditions may benefit in the future? Potential targets include diabetic foot ulcers, burn injuries, and traumatic wounds where healing is impaired.

Are there any business ties involved? Yes. The innovation is being developed through Traxion Biotech, a company established by the study’s lead researchers.

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