Relationship between scaffold channel diameter and number of regenerating axons in the transected rat spinal cord

Aaron J. Krych, Gemma E. Rooney, Bingkun Chen, Thomas C. Schermerhorn, Syed Ameenuddin, Lou Ann Gross, Michael J. Moore, Bradford L. Currier, Robert J. Spinner, Jonathan A. Friedman, Michael J. Yaszemski, Anthony J. Windebank

Research output: Contribution to journalArticlepeer-review

59 Scopus citations


Regeneration of endogenous axons through a Schwann cell (SC)-seeded scaffold implant has been demonstrated in the transected rat spinal cord. The formation of a cellular lining in the scaffold channel may limit the degree of axonal regeneration. Spinal cords of adult rats were transected and implanted with the SC-loaded polylactic co-glycollic acid (PLGA) scaffold implants containing seven parallel-aligned channels, either 450 μm (n = 19) or 660 μm in diameter (n = 14). Animals were sacrificed after 1, 2 and 3 months. Immunohistochemistry for neurofilament expression was performed. The cross-sectional area of fibrous tissue and regenerative core was calculated. We found that the 450 μm scaffolds had significantly greater axon fibers per channel at the 1 month (186 ± 37) and 3 month (78 ± 11) endpoints than the 660 μm scaffolds (90 ± 19 and 40 ± 6, respectively) (p = 0.0164 and 0.0149, respectively). The difference in the area of fibrous rim between the 450 and 660 μm channels was most pronounced at the 1 month endpoint, at 28,046 ± 6551 and 58,633 ± 7063 μm2, respectively (p = 0.0105). Our study suggests that fabricating scaffolds with smaller diameter channels promotes greater regeneration over larger diameter channels. Axonal regeneration was reduced in the larger channels due to the generation of a large fibrous rim. Optimization of this scaffold environment establishes a platform for future studies of the effects of cell types, trophic factors or pharmacological agents on the regenerative capacity of the injured spinal cord.

Original languageEnglish (US)
Pages (from-to)2551-2559
Number of pages9
JournalActa Biomaterialia
Issue number7
StatePublished - Sep 2009


  • Biomedical engineering
  • Central nervous system
  • Polymeric scaffolds
  • Tissue development and growth

ASJC Scopus subject areas

  • Biotechnology
  • Biomaterials
  • Biochemistry
  • Biomedical Engineering
  • Molecular Biology


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