Peter J Grahn1, Sandeep Vaishya2, Andrew M Knight2, Bingkun K Chen2, Ann M Schmeichel2, Bradford L Currier2, Robert J Spinner3, Michael J Yaszemski4, Anthony J Windebank5. 1. Mayo Graduate School, Mayo Clinic, Rochester, 200 First Street SW, MN 55905, USA. 2. Department of Neurology, Mayo Clinic, Rochester, 200 First Street SW, MN 55905, USA. 3. Department of Neurosurgery, Mayo Clinic, Rochester, 200 First Street SW, MN 55905, USA. 4. Department of Orthopedic Surgery, Mayo Clinic, Rochester, 200 First Street SW, MN 55905, USA. 5. Mayo Graduate School, Mayo Clinic, Rochester, 200 First Street SW, MN 55905, USA; Department of Neurology, Mayo Clinic, Rochester, 200 First Street SW, MN 55905, USA. Electronic address: windebank.anthony@mayo.edu.
Abstract
BACKGROUND CONTEXT: Traumatic injuries occurring at the conus medullaris of the spinal cord cause permanent damage both to the central nervous system and to the cauda equina nerve roots. PURPOSE: This proof-of-concept study was to determine whether implanting the nerve roots into a biodegradable scaffold would improve regeneration after injury. METHODS: All experimental works involving rats were performed according to the approved guidelines by the Mayo Clinic Institutional Animal Care and Use Committee. Surgical procedures were performed on 32 Sprague-Dawley rats. Four ventral cauda equina nerve roots were reimplanted either directly into the ventral cord stump or through a poly(lactic-co-glycolic acid) (PLGA) scaffold. These experimental groups were compared with a control group in which the nerves were inserted into a muscle fascia barrier that was placed between the spinal cord and the nerve roots. Animals were sacrificed at 4 weeks. RESULTS: There was no difference in motor neuron counts in the spinal cord rostral to the injury in all treatment groups, implying equal potential for the regeneration into implanted nerve roots. One-way analysis of variance testing, with Tukey post hoc test, showed a statistically significant improvement in axon regeneration through the injury in the PLGA scaffold treatment group compared with the control (p<.05, scaffold n=11, control n=11). CONCLUSIONS: This pilot study demonstrated that a PLGA scaffold improved regeneration of axons into peripheral nerve roots. However, the number of regenerating axons observed was limited and did not lead to functional recovery. Future experiments will employ a different scaffold material and possible growth factors or enzymes to increase axon populations.
BACKGROUND CONTEXT: Traumatic injuries occurring at the conus medullaris of the spinal cord cause permanent damage both to the central nervous system and to the cauda equina nerve roots. PURPOSE: This proof-of-concept study was to determine whether implanting the nerve roots into a biodegradable scaffold would improve regeneration after injury. METHODS: All experimental works involving rats were performed according to the approved guidelines by the Mayo Clinic Institutional Animal Care and Use Committee. Surgical procedures were performed on 32 Sprague-Dawley rats. Four ventral cauda equina nerve roots were reimplanted either directly into the ventral cord stump or through a poly(lactic-co-glycolic acid) (PLGA) scaffold. These experimental groups were compared with a control group in which the nerves were inserted into a muscle fascia barrier that was placed between the spinal cord and the nerve roots. Animals were sacrificed at 4 weeks. RESULTS: There was no difference in motor neuron counts in the spinal cord rostral to the injury in all treatment groups, implying equal potential for the regeneration into implanted nerve roots. One-way analysis of variance testing, with Tukey post hoc test, showed a statistically significant improvement in axon regeneration through the injury in the PLGA scaffold treatment group compared with the control (p<.05, scaffold n=11, control n=11). CONCLUSIONS: This pilot study demonstrated that a PLGA scaffold improved regeneration of axons into peripheral nerve roots. However, the number of regenerating axons observed was limited and did not lead to functional recovery. Future experiments will employ a different scaffold material and possible growth factors or enzymes to increase axon populations.
Authors: Michael J Moore; Jonathan A Friedman; Eric B Lewellyn; Sara M Mantila; Aaron J Krych; Syed Ameenuddin; Andrew M Knight; Lichun Lu; Bradford L Currier; Robert J Spinner; Richard W Marsh; Anthony J Windebank; Michael J Yaszemski Journal: Biomaterials Date: 2005-08-31 Impact factor: 12.479
Authors: Godard C de Ruiter; Irene A Onyeneho; Ellen T Liang; Michael J Moore; Andrew M Knight; Martijn J A Malessy; Robert J Spinner; Lichun Lu; Bradford L Currier; Michael J Yaszemski; Anthony J Windebank Journal: J Biomed Mater Res A Date: 2008-03-01 Impact factor: 4.396
Authors: Godard C W de Ruiter; Martijn J A Malessy; Awad O Alaid; Robert J Spinner; JaNean K Engelstad; E J Sorenson; K R Kaufman; Peter J Dyck; Anthony J Windebank Journal: Exp Neurol Date: 2008-01-08 Impact factor: 5.330
Authors: Godard C W de Ruiter; Martijn J A Malessy; Michael J Yaszemski; Anthony J Windebank; Robert J Spinner Journal: Neurosurg Focus Date: 2009-02 Impact factor: 4.047
Authors: Jonathan A Friedman; Anthony J Windebank; Michael J Moore; Robert J Spinner; Bradford L Currier; Michael J Yaszemski Journal: Neurosurgery Date: 2002-09 Impact factor: 4.654
Authors: Godard C de Ruiter; Robert J Spinner; Martijn J A Malessy; Michael J Moore; Eric J Sorenson; Bradford L Currier; Michael J Yaszemski; Anthony J Windebank Journal: Neurosurgery Date: 2008-07 Impact factor: 4.654
Authors: Peter J Grahn; Stephan J Goerss; J Luis Lujan; Grant W Mallory; Bruce A Kall; Aldo A Mendez; James K Trevathan; Joel P Felmlee; Kevin E Bennet; Kendall H Lee Journal: Spine (Phila Pa 1976) Date: 2016-07-01 Impact factor: 3.241