(114b) Characterization of Salt Templated Hyaluronic Acid Hydrogels for Neural Wound Healing

Peripheral nerve injury is a frequent occurrence affecting a considerable percentage of trauma patients annually. Although significant advances have been made in the area of nerve regeneration, there is a need for long range order to impart contact guidance for bridging large injury gaps. Hyaluronic acid is a natural polymer intimately involved in the body's wound healing process and is commonly employed for neural regenerative therapies. Hydrogels of this polymer, however, are traditionally amorphous and only provide chemical regenerative support to the injury site. Salt thermally dissolved in the hydrogel solution above the room temperature saturation concentration will spontaneously nucleate out of the solution upon cooling. Pores formed by this process are the negative imprint of the salt crystals. Previous work in this area completed in two-dimensions demonstrates the rapid ability of crystalline matter to restrict hydrogel to the interstitial crystalline space. This novel method of imposing an internal architecture through three dimensional gels uniquely yields both chemical and physical guidance in the injury site without the need for therapeutic additives. We hypothesize that by exploiting the ability to stabilize salt-derived channels within hyaluronic acid gels, the resulting bulk material properties will promote cell preferential growth and/or neurite extension along the path mapped by this structural template. Long range internal templating of these uniquely patterned liquid crystals is expected to improve the efficacy of regenerated nerves.