Around 8% of people in the United States have diabetes, and in Europe that figure stands at 5%. One of the complications of diabetes is that nerves in the lower legs and feet get damaged, which increases the risk of ulcers forming. Sometimes an ulcer will form because the person simply did not feel a stone in their shoe or they were not aware of footwear rubbing against the skin. Then other aspects of diabetes - such as poor blood supply to the feet and a compromised immune system - means the wounds can be hard to treat and slow to heal.
Diabetic foot ulcers are costly, both to the health system (15% of people with diabetes develop foot ulcers and 70% of ulcers re-occur within five years) and put the individual at risk of needing an amputation. And if an infection enters the wound and spreads to the blood stream it can threaten the life of the patient.
At UCD Charles Institute, the Wang group are developing a temperature-responsive dressing that can be placed on a chronic diabetic wound and delivers stem cells to the site. This new polymer-based system will contain stem cells derived from fat tissue and it will also contain key ‘extracellular matrix’ biomolecules such as hyaluronic acid, collagen or gelatine to support the stem cells and help them grow.
This smart wound dressing will be liquid at room temperature, but when it is applied to the wound, it will turn into a hydrogel thus forming a dressing as well as a reservoir system to secrete essential molecules for accelerated wound healing in chronic diabetic ulcers (figure 1).
Figure 1: An advanced in-situ stem cell based dressing system with unique thermoresponsive and crosslinkable properties for the treatment of chronic diabetic wounds