Evaluating conductive pedot:PSS hydrogel in promoting neural rehabilitation

honors thesisCollege of engineeringChemical EngineeringHuanan ZhangPeripheral nervous injuries (PNI) affect millions of individuals every year and present a significant challenge for physicians. Surgeons have used suturing techniques to repair short sections of damaged nervous tissue, but past a critical distance must resort to nerve guidance conduits (NGC). One material that has begun receiving attention for applications in NGCs is PEDOT:PSS hydrogel. A facile and scalable synthesis of the hydrogel with 4-dodecylbenzenesulfonic acid (DBSA) provides mechanical tunability and conductivity properties that can be leveraged to encourage PNI recovery. The study aims to explore the potential of this material in NGC applications. First, rheology experimentation was conducted to construct a hydrogel surface that has elastic properties that mimic peripheral nervous tissue. Next, a patterned film was created by spin coating the gel on top of a glass slide covered in a layer of SU-8 2000 epoxy and a patterned polyvinyl tape mask. The final stage involved post-fabrication surface modifications followed by differentiation of hybrid rat neuroblastoma and mouse glioma (NG108) cells on the hydrogel. Neurite outgrowths were measured using NeuronJ to quantify the impact that the hydrogel had on NG108 cell differentiation. Fabrication of the PEDOT:PSS hydrogel was successful as the film was homogenous, biomechanically similar to nervous tissue, and translucent for cell visualization. Despite fabrication success, the hydrogel was found to slightly inhibit NG108 cell differentiation suggesting the mechanical and topographical properties will not encourage PNI rehabilitation by themselves. However, the inhibition was not significant enough to discourage future efforts to explore the effects of hydrogel stimulation on NG108 differentiation