Electrically Conductive Biomaterials for the Preservation and Regeneration of Soft Tissue

Combat trauma results in severe, complex injuries involving multiple tissue types. There is growing evidence that an electrical stimulus applied to a wound can enhance tissue regeneration. Therefore, in early wound management, it is important to optimise endogenous responses, including the bioelectric current. To fabricate electroactive wound dressings for external application, we have incorporated a network of the conductive polymer polypyrrole (PPY) into both biodegradable and non-biodegradable wound care products. We also used polycaprolactone to render internal wound dressings electrically conductive. Alongside this, we have developed electrically controlled delivery methods using conductive polymers incorporated into wound dressings for therapeutic use, which enhance tissue preservation. In parallel, we investigated the migratory and proliferative properties of skin cell types and their response to electrical stimulation. Comparison of pristine wound dressings to PPY-coated wound dressing shows that foam, alginate and aquafiber-based dressings are electrically conductive. Preliminary data show that the drug can be electrochemically loaded into the wound dressings and released upon electrical stimulation. We have also developed an electrical stimulation paradigm by performing wound healing experiments on indium tin oxide-coated glass and applying an electrical stimulus. Fibroblasts demonstrate enhanced wound healing at 50mV/mm direct current (DC) electrical stimulation. Conductive wound dressings will enable direct electrical stimulation of the wound to promote regenerative activity. When combined with a drug delivery system, this will enable localised drug release at the wound, stimulating wound healing. The wound dressings will also provide a direct electrical stimulation to the wound. Overall, we aim to aid the healing of complex wounds by enhancing the endogenous regenerative response of cells in the skin, thereby decreasing the recovery period.