(618ad) The Incorporation of Electrically Conducting Polymer within Natural-Polymer Hydrogels

Hydrogels that incorporate water content, internal architecture and porosities similar to that of native tissue have shown promise in the field of tissue engineering and regenerative therapies. The ability to leverage these properties to the fullest extent can only happen if the scaffolds embody many of the known attributes beneficial to wound healing: electrical conductivity, internal architecture, and embodying chemical makeup mimic of the native extracellular matrix. Thiol “click” chemistry has been incorporated into hyaluronic acid hydrogel films to exploit the hydrolysable bonds at physiological pH. The thiol groups are used to crosslink the hydrogel and allow additional functionalites to be incorporated within the polymer matrix.

This work attempts to evaluate the ability to incorporate an electrically conducting polymer within an anionic hydrogel. Electrical conductivity is expected to increase the efficacy of wound healing obtained and by permitting local, modulated drug release in combination with the regenerative properties inherent to the bulk polymer. Pyrrole, a biocompatible polymer, has been extensively used in neural applications such as neural electrodes and nerve regeneration. High electrical conductivity and ease of synthesis make this polymer a viable candidate for this work. We hypothesize that the successful inclusion of this polymer within the bulk hydrogel will give rise to electrical conductivity—a necessity in maximizing the hydrogels’ wound healing capabilities.

Various methods to incorporate the conducting polymer will be investigated. A suspension of pyrrole monomer within a bulk polymer solution functionalized with methacrylate and pyrrole groups to create a liquid bi-phase system will be evaluated. The pyrrole monomers are expected to coalesce to form domains within the bulk hydrogel that behave as conductivity channels within the hydrogel by connecting to the conductive surface. A second proposed method uses a four-armed thiol to react a methacrylated pyrrole- hyaluronic acid hydrogel solution with the conductive substrate. That is, the hydrogel will be chemically crosslinked and covalently bound to the conductive substrate simultaneously. A final method to incorporate electro conductivity within the hydrogel is to leverage a surfactant to catalyze conductive domain formation within the gel. Each of these methods leverages biocompatibility of natural, biodegradable polymers with the advantages of conductivity and cleavable bonds.