Design of a Biomimetic Hydrogel Nanocomposite Material for Responsive Wound Management

Abstract

Current wound management technology can inhibit the healing process due to poor adhesion to the wound surface, low uptake of exudate, and lack of inherent antimicrobial properties. Alternatives to traditional wound dressings include hydrogels, which are supramolecular matrices, stabilized by non-covalent interactions that absorb large amounts of fluid and exhibit flexible behavior. This research uses an amino acid-calcium complex to crosslink an alginate hydrogel which is further functionalized with metal (Ag, Au) nanoparticles. Previous research has shown that amino acids such as tryptophan and serine have increased the non-covalent interactions within the network, resulting in greater gel strength. The hydrodynamic radius and structural diversity of the amino acid has also been shown to exhibit an inverse relationship between the gels ability to swell and its tensile strength. To harness the porosity and swelling capacity of the hydrogel, conductive polymers polyaniline (PANI) or polypyrrole (PPy) can be layered onto the biomimetic hydrogel to yield a responsive wound dressing. As wound secretions diffuse through the hydrogel and into the electroactive layer, the conductivity of the matrix increases and induces an electrochemical signal. The efficacy of the composite is characterized by simultaneously measuring swellability and the increase in conductivity, indicating the point of saturation. Initial results showed that after 150 minutes in a simulated wound environment, the composite swelled upwards of 150% and increased in conductivity up to 20%.