The smart bandage. (Image: Caltech)

When someone gets a wound of any sort, the body usually heals on its own. This is not always the case, though, and such chronic wounds are not just debilitating for the people suffering from them. They’re also a drain on healthcare systems — representing a $25 billion financial burden in the U.S. alone each year.

A Caltech-developed new kind of smart bandage aims to treat lingering wounds and help those people who have trouble recuperating — e.g., diabetics.

“There are many different types of chronic wounds, especially in diabetic ulcers and burns that last a long time and cause huge issues for the patient,” said assistant professor Wei Gao. “There is a demand for technology that can facilitate recovery.”

A typical bandage might only consist of layers of absorbent material, whereas these smart bandages are made from a flexible, stretchy polymer containing embedded electronics and medication. The electronics allow the sensor to monitor for molecules like uric acid or lactate and conditions like pH level or temperature in the wound that may be indicative of inflammation or bacterial infection.

A larger version of the smart bandage. (Image: Caltech)

The bandage can respond in one of three ways. It can transmit the gathered data from the wound wirelessly to a nearby computer, tablet, or smartphone for review; it can deliver an antibiotic or other medication stored within the bandage directly to the wound site to treat the inflammation and infection; or it can apply a low-level electrical field to the wound to stimulate tissue growth, resulting in faster healing.

In animal models under lab conditions, the smart bandages provided real-time updates about wound conditions and the animals’ metabolic states, and offered speed healing of chronic infected wounds similar to those found in humans. Gao said the results are promising and added that future research will focus on improving the bandage technology and testing it on human patients.

“We have showed this proof of concept in small animal models, but down the road, we would like to increase the stability of the device and also to test it on larger chronic wounds because the wound parameters and microenvironment may vary from site to site,” he said.

Here is a Tech Briefs interview with Gao, edited for length and clarity.

The flexibility of Wei Gao’s smart bandages means they can stay on even while skin stretches and moves. (Image: Caltech)

Tech Briefs: What inspired your research?

Gao: Chronic wounds are affecting tens of millions of people in the world, causing a major financial burden in our healthcare system. Right now, most therapies require invasive surgery. There is an urgent demand for personalized and non-invasive wound treatment. Moreover, monitoring wound fluid biomarkers can provide insightful information for wound status toward enhanced treatment. Thus, we decided to develop a smart bandage that can perform wound monitoring and conduct wound therapy to improve chronic wound management.

Tech Briefs: What were the biggest technical challenges you faced?

Gao: The complex wound matrix could substantially influence the biosensor performance. Typical biosensors will suffer from biofouling and have a limited lifetime. Thus, we need to optimize our sensor design for long-term, accurate wound biomarker analysis.

Tech Briefs: Can you explain in simple terms how the technology works?

Gao: Our wearable smart bandage has two main functions: Its sensor array can simultaneously monitor multiple chemicals in wound fluids that reflect the metabolic and inflammatory status of the wound; it can also perform combination wound treatment through controlled delivery of an anti-inflammatory, antimicrobial drug to treat wound infection and through electrical stimulation, to facilitate tissue regeneration for faster wound healing.

Tech Briefs: Are there any set plans for future research?

Gao: We are working on obtaining the human subject study protocol and plan to perform the pilot study with human subjects over the next year or two.

Further work needs to be done to enhance the long-term stability of the wearable sensor for continuous wound biomarker analysis. In the meantime, more evaluation in large animal models and human subjects needs to be conducted to evaluate the smart bandage.