Wounds represent a growing health care issue affecting thousands of patients. A 2020 study published in BMJ Open found that the annual NHS cost of wound management was £8.3bn between 2017/2018, of which £2.7bn and £5.6bn were associated with managing healed and unhealed wounds respectively.

Now, engineers and clinical academics at NTU and NUH have developed technology to be embedded into dressings so that they do not need to be continually removed and replaced to assess how a wound is healing. They believe the textile-based printed protein sensor could help to reduce the risk of patients becoming seriously ill and prevent amputation.

Dr Yang Wei said that the sensor analyses chemical biomarkers to give an indication of whether a wound is healing or not. The dressing is currently powered via a USB but a coin cell battery, such as CR2035, will sustain the function for over eight hours.

He added that non-woven polypropylene fabric acts as the absorbent layer with polyurethane as the backing. The protein sensor consists of electrodes that are directly screen-printed using silver and carbon composite inks on the polypropylene fabric, which was chosen due to its widespread use in wound dressings.

“The sensor consists of four layers and each layer is deposited directly on to textile using screen printing, subsequent curing process solidifies the printed layers through either heat at low temperature or UV light.” Dr Yang Wei, Nottingham Trent University

Dr Wei emphasised that the sensitivity of the sensor is 0.0026uA/M and the average selectivity over other artefacts, such as creatine, is 0.4.

Currently, health professionals visually assess the condition of a chronic wound by removing the dressing, which risks lengthening the healing process, can make scarring worse, or introduce an infection. The dressing also needs replacing each time the wound is checked.
The new sensor uses the electrodes to analyse the concentration of specific proteins in a wound constantly and in real time. By doing so it determines whether the dressing requires changing, can come off completely or if the wound has an infection.

Using app-based technology, the patient would be able to take a reading and receive some simple information by holding a smartphone near to the dressing. They would then be able to book an appointment, if necessary, so that it can be checked by a clinician.The researchers said the next step will be to work with consultant clinicians and digital technology providers to commercialise the advance.

The Nottingham Trent University team’s work, which involved industry partner Kymira, is published in Scientific Reports.