Biosensor bandage helps in the recovery of chronic wounds

Yet another area of healthcare is exploring the potential of biosensors to offer more efficient treatments: that of smart bandages. Cuts, scrapes, burns, or other injuries may seem like something harmless for which the body itself guarantees instant healing. However, this is not true for those with diabetes and/or a slower and more difficult healing process, who may be at risk of chronic wounds, infections and even amputations.

Wound care is a worldwide, multi-billion dollar problem. In the United States alone, it affects 6.7 million people or about 2% of the population at an annual cost of US$ 25 billion. Current therapies use drugs, skin grafts, negative pressure, among others, but can reach emergency surgical interventions, increasing morbidity and mortality risks. In addition, microbial infections at the wound site can severely prolong the healing process and lead to necrosis, sepsis and even death.

Topical and systemic antibiotics are increasingly prescribed for patients suffering from chronic wounds, but overuse, misuse and misapplication of antibiotics are leading to increasing resistance of bacteria to the drugs, causing further harm to patients and the healthcare system in general.

To help combat this enemy, Caltech researchers have developed a new type of smart bandage that could make wound care easier, more effective and cheaper.

“There are many types of chronic wounds, especially diabetic ulcers and burns, that last a long time and cause big problems for patients. There is a demand for some kind of technology to facilitate recovery”, explains Wei Gao, assistant professor of medical engineering and research fellow at Caltech’s Heritage Medical Research Institute.

Chronic wound healing is a highly complex biological process consisting of four integrated and overlapping phases: haemostasis, inflammation, proliferation, and remodelling. At each of these stages, the chemical composition of the wound changes substantially, indicating the stage of healing and even the presence of an infection. For example, increased temperature is associated with bacterial infection, and changes in temperature can provide information about various factors relevant to healing.

Unlike a conventional bandage, composed of layers of absorbent material, smart bandage are made of a flexible, elastic polymer containing embedded electronics and medicines. Sensors monitor molecules such as uric acid or lactate, as well as conditions such as the wound’s pH level or temperature, which can indicate inflammation or bacterial infection.

The smart bandage can answer problems in three ways: first, it can transmit data collected from the wound to a nearby computer, tablet or smartphone, using wireless technology, for follow-up by the patient or a healthcare professional. Second, it can administer an antibiotic or other medication stored in the dressing, injecting it directly into the wound site to treat inflammation or infection. And you can also apply a low-level electric field to the wound to stimulate tissue growth, resulting in faster healing.

In the laboratory, smart bandages have been shown to provide accurate real-time information on wound conditions and metabolic states, and show a similar rate of healing of chronic infected wounds to that found in usual conditions.

The researchers said the results are promising and that future research, in collaboration with other institutions, will focus on improving the technology and testing it in humans, whose therapeutic needs may differ from those of laboratory animals.

“We have shown this proof of concept in small animal models, but we would like in the future to increase the stability of the smart bandage and also test it on larger chronic wounds, because wound parameters and the microenvironment may vary,” Gao comments.

O artigo que descreve a pesquisa. “A stretchable wireless wearable bioelectronic system for multiplexed monitoring and combination treatment of infected chronic wounds”, foi publicado na edição de 24 de março da revista Science Advances.