Poly(3,4-ethylenedioxythiophene) on decellular scaffolding interrupts grafted muscle revascularization

Regenerative peripheral nerve interfaces (RPNIs) are implantable devices for amputee communication between peripheral nerves and microprocessor controlled robotic prostheses. Our RPNIs consist of transferred muscles reinnervated by the peripheral nerves remaining in the limb post amputation. RPNI construction includes a light muscle wrap of decellularized small-intestine submucosa (SIS). We studied RPNI revascularization and regeneration when SIS had an electrically conductive coating of poly 3,4 ethylene dioxytheophene (PEDOT). Rats underwent free-muscle transfer (FMT). The peroneal nerve was divided and the proximal end was implanted in the FMT. Experimental groups received either: a) no SIS (NONE), b) SIS (SIS) wrap, or c) wrap of SIS polymerized with PEDOT, (SIS+PEDOT). One week later, rats were perfused with lead oxide, vascular areas were quantified and histology was performed. SIS+PEDOT group muscles contained less revascularization under the wrap than the SIS group, (p=.05). Histology showed that at 7 days, muscle fibers in the SIS+PEDOT group were not degenerating and regenerating similarly to those muscle fibers in the NONE and SIS groups. Images of SIS and SIS+PEDOT indicate the PEDOT filled the pores of the SIS. This reduced porosity may prohibit revascularization through the SIS+PEDOT. Data indicate that revascularization in the NONE and SIS groups are similar to control muscle while vascularity in the SIS+PEDOT group is impaired by SIS+PEDOT.