Development of Softening Polymer-based Spinal Cord Stimulation Leads for Chronic Applications

Spinal cord stimulation (SCS) leads are a type of neural interface that can be implanted in the epidural space and deliver electrical pulses to change or block signals traveling to the brain. SCS leads are commonly used to alleviate chronic back pain resulting from failed back surgery syndrome and other injury and disease-related conditions. Recently, researchers have tried to develop treatments to restore movement in patients with a spinal cord injury. However, clinical cervical SCS has been limited by the size of the SCS leads, the small epidural space around the cervical spinal cord, and the large degree of movement of the neck. Furthermore, commercially available SCS leads are not compatible for their use in small animal models where most of the preclinical research is done. Therefore, in this dissertation work, we (1) have developed a thinfilm softening SCS lead that can be implanted in the cervical spinal cord of a rat model and evoke muscle responses after SCS. (2) We have also developed ester-free nondegradable softening polymer-based SCS leads, and (3) have shown their in vitro long-term electrochemical stability to assess their potential use in chronic studies.