Grants Funded

Abstract
Neuromuscular integrated prosthetic devices are often lauded as life altering for those living with amputations. These devices often utilize efferent neuromuscular signals but lack any appreciable sensory afferent input that would generate appropriate proprioception and tactile feedback. This often means that users of these devices must visualize the device with every activity, often causing significant mental fatigue and eventual abandonment of the device up to 75% of the time. To prevent device rejection, development of an ideal prosthetic interface is key. Ideally, this would involve a closed loop system with efferent motor control signals alongside afferent sensory feedback. A novel surgical strategy to address this issue is the composite regenerative peripheral nerve interface (C-RPNI). The overall objectives of this proposal are to develop and demonstrate viability of this C-RPNI in addition to its feasibility as a singular biologic interface where high fidelity motor control is provided simultaneously alongside sensory feedback from the device. The C-RPNI is created by surgically implanting the transected peripheral nerve into a scaffold composed of a segment of free muscle graft sutured to dermal skin graft. This scaffold was developed under the hypothesis that mixed peripheral sensorimotor nerves would display preferential motor nerve reinnervation to the muscle graft segment and sensory reinnervation to the dermal component of the C-RPNI, with this construct remaining stable over time. With the support of prior human and animal trials demonstrating success of the muscle-only RPNI for efferent motor signals, this hypothesis will be tested by pursuing two aims: (1) characterize construct viability, regeneration, and preferential motor and sensory organ reinnervation of the C-RPNI by a mixed sensorimotor nerve; and (2) differentiate electrophysiological signal transduction capabilities of both dermal and muscle components of the C-RPNI following targeted stimulation. Experiments will be conducted utilizing rats as an animal model. Preferential innervation will be assessed with histological analysis, and signal transduction capabilities will be determined through the use of electrodes with simultaneous recording and stimulating abilities. Demonstrating both of these aims would encourage further progress towards the development of the ideal closed loop intuitive prosthetic device.

Biography
Shelby Svientek, MD joined the Division of Plastic Surgery at the University of Michigan as an integrated plastic surgery resident in 2016. She graduated from the University of Illinois with a Bachelor of Science in Bioengineering and later earned her medical degree at Loyola University Chicago, graduating magna cum laude with Alpha Omega Alpha Honors Society membership. Dr. Svientek has demonstrated long-standing interest in biomedical research. She initially pursued research into calcium phosphate bone scaffolding for craniofacial defects, earning several awards and scholarships at the undergraduate level. During medical school, with the award of the Student Training in Approaches to Research Grant, she created an in vitro model for urothelium, developing both the culture methodology and scaffold system. While in residency, Dr. Svientek investigates the differences in pain behaviors and signaling between genders in rats as well as works towards developing the ideal neuroma model. In her spare time, Dr. Svientek enjoys cooking, running, gardening, and volunteering, notably founding a community garden in the west side of Chicago during medical school. In the future, Dr. Svientek plans to pursue fellowship training to further her skills in nerve and micro-vascular reconstruction. Her career goal is to run a clinical practice helping patients with debilitating nerve injuries in addition to running a laboratory researching nerve regeneration and interfaces.