Abstract
Background The use of nerve conduits to facilitate nerve regrowth after peripheral nerve injury
is limited to defects less than 3 cm. The purpose of this study is to determine the
capability of novel single and multi-lumen poly(ethylene glycol) (PEG) conduits manufactured
by stereolithography to promote peripheral nerve regeneration.
Materials and Methods Eight Sprague Dawley rats with sharp transection injuries of the sciatic nerve were
randomly assigned to receive single-lumen or multi-lumen PEG conduits to bridge a
10-mm gap. Sciatic nerve and conduit samples were harvested after 5 weeks, and axon
number, myelin thickness, fiber diameter, and g-ratio were analyzed. The contralateral
intact nerve was also harvested for comparison.
Results Partial nerve regeneration was observed in three out of four single-lumen conduits
and one out of four multi-lumen conduits. Axon number in the single-lumen regenerated
nerve approached that of the contralateral intact nerve at 4,492 ± 2,810.0 and 6,080 ± 627.9
fibers/mm2, respectively. The percentage of small fibers was greater in the single-lumen conduit
compared with the intact nerve, whereas myelin thickness and g-ratio were consistently
greater in the autologous nerve. Axon regrowth through the multi-lumen conduits was
severely limited.
Conclusion Single-lumen stereolithography-manufactured PEG nerve conduits promote nerve regeneration,
with regenerating axon numbers approaching that of normal nerve. Multi-lumen conduits
demonstrated significantly less nerve regeneration, possibly due to physical properties
of the conduit inhibiting growth. Further studies are necessary to compare the efficacy
of the two conduits for functional recovery and to elucidate the reasons underlying
their differences in nerve regeneration potential.
Keywords
peripheral nerve repair - stereolithography - nerve conduit - poly(ethylene glycol)
- multi-lumen - single-lumen
