Low Loading of Collagen in Electrospun Polyester Nerve Conduits for Repairing Segmental Nerve Defect: An Experimental Study Using the Tibial Nerve in Rats with Multiple Measurements.

The present study provides trials of electrospun poly(l-lactide--caprolactone), PLCL, copolymer 67:33 mol %, and electrospun PLCL blend with a low loading of collagen (0.5% w/v), PLCL-Col, as a connecting porous biodegradable nerve conduit to repair 7 mm long segmentary tibial nerve lesions in rats compared with the standard autograft technique. The electrospun PLCL scaffolds reveal a matrix of fibers with a mean diameter of 476 ± 60 nm and an average pore size of 253 ± 5 nm. Blending collagen with the PLCL results in a comparatively denser matrix of fibers with a mean diameter of 417 ± 42 nm and a pore size of 244 ± 3 nm. For testing, a total of 30 male Wistar rats were divided into 3 groups of 10 and each group was subjected to a different nerve repair procedure for evaluation of nerve regeneration after reconstruction. Evaluation of nerve regeneration was compared in terms of the tibial functional index (TFI), nerve conduction velocity (NCV), gastrocnemius muscle weight (%GMW), and a histomorphometric study. After 12 weeks of implantation, there was evidence of nerve regeneration across the gap from the histomorphologic study. All parameters of nerve regeneration were observed in every animal of the study groups. Our results clearly showed that there are reinnervation and return of function in all groups, similarly to the autograft group. PLCL-Col showed better results than PLCL and autograft, which suggested that PLCL-Col porous conduits may serve as a scaffold for peripheral nerve regeneration.