(351g) Physiochemical Characterization of Hyaluronic Acid-Methylcellulose Hydrogels for Mitochondria Transplantation

Spinal Cord Injury (SCI) is serious neurological condition that poses long-term health concerns to the affected individuals. Not only due to the serious physical damage that happens to neuronal and motor functions, but this initial injury is further exacerbated by a series of pathophysiological and biochemical changes that follow the initial traumatic incident. The leakage of cytosol and blood from ruptured neurons and blood vessels cause ion imbalances and excitotoxicity leading ultimately to the loss of neuronal functions and sequential cellular death. The delivery of isolated mitochondria to the site of SCI has been shown to be a possible solution to stemming this initial injury. Mitochondria transplantation improves cellular bioenergetics and reduces concentration of reactive oxygen species achieving homeostasis and neuroprotection. Nonetheless, keeping mitochondria viable outside the cytosolic environment for anytime longer than a few minutes has been a significant challenge to this therapeutic approach. Moreover, localized delivery to the injury site is also limited by other factors including flow of cerebrospinal fluid that disintegrates mobilized organelle breaking them away of injury site. In this work, we are investigating physiochemical properties of hyaluronic acid methylcellulose hydrogels (HA-MC) as a delivery vehicle for transplanting mitochondria to SCI. A proper blend of methylcellulose and hyaluronic acid hydrogels proves to be viable delivery system that may overcome mitochondrial transplantation challenges. Methylcellulose possesses reverse thermogelation properties that allow it to phase separate/gel when heated above the lower critical solution temperature (LCST). HA-MC allow for controlled release of mitochondria around the injury site allowing for an effective uptake by compromised neuronal cells. Ultraviolet-visible spectroscopy have been used to measure optical density of hydrogels at verifying temperatures as a measure of phase separation/gelation. Fluorescence microplate reader was used to study dye-labeled HA-MC hydrogels’ dissolution and mitochondrial release in-vitro. Seahorse assay was used to assess mitochondrial respiration and viability.