FIG. 2.

SMU fabrication and surgical procedures. To create larger engineered skeletal muscle tissues more closely matching the VML defect, (A) individual tdT SMUs composed of skeletal muscle supported by bone–tendon anchors, (B) were transferred in sets of three to a common substrate, and (C) were combined by pinning the bone–tendon anchors together. After creating a VML injury in GFP rats by removing ∼30% of the TA muscle, either (D) the defect was left unrepaired except for a redirected nerve branch and its supporting vasculature, or (E) a combined SMU was implanted to fill the defect. Black arrowheads indicate the redirected nerve. Following 28 days of recovery, a representative TA muscle is pictured from (F) the VML Only group, and (G) the VML+SMU group. Graft and contralateral TAs were subsequently explanted, weighed, and preserved for histology. GFP, green fluorescent protein; SMU, skeletal muscle unit; TA, tibialis anterior; VML, volumetric muscle loss.