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A Simple Technique for Augmentation of Axonal Ingrowth into Chondroitinase Treated Acellular Nerve Grafts using Nerve Growth Factor
46.."3:
.&5)0%4
According to the findings, MSC treatment has positive effects on both preservation of muscle mass and functional healing following muscle neurotization. The MSC enhance the functional results after NMN and can be used as an alternative to Schwann cells.
Lyophilized chondroitinase-treated murine nerve grafts were doped with varied concentrations of NGF and subsequent ELISA analysis was used to calculate the quantity of NGF present in the grafts. A murine sciatic nerve injury model was used to evaluate the effectiveness of the grafts. Grafts were implanted into 3 experimental (NGF-treated) and 3 control rats for 5 days. Axonal regeneration into the grafts was assessed by immunocytochemical analysis in frozen sections. Digital image analysis was used to characterize and compare the growth-factor induced axons to those in the control grafts. Descriptive statistics including counts, means, and standard error of the mean (+/SEM) were used to summarize data as appropriate. Univariate analysis was performed on axon counts and areas using the Student's t-test for independent samples.
3&46-54
Figure 1
PAPER 69 4BUVSEBZ 4FQUFNCFS t1. $MJOJDBM1BQFS4FTTJPO/FSWF#BTJD3FTFBSDI
A non-linear concentration-dependent loading of our nerve grafts with NGF was demonstrated using this technique (Figure 1). Subsequent analysis of these grafts in our in vivo model showed a higher axon count in the NGF group, consistent throughout the length of the nerve grafts with an average of 1035.9 +/- 41.1 axons versus 552.3 +/- 18.1 axons in the control grafts (P<0.0001) (Figure 2). Although the NGF group displayed a higher axon count per slice, the mean diameter of the individual NGF axons was smaller at 2.40 +/- 0.03 m versus 3.46 +/- 0.06 m for the control grafts (P<0.0001), consistent with induction of sensory axons [4,5].
46.."3:10*/54 ∙
A Simple Technique for Augmentation of Axonal Ingrowth into Chondroitinase Treated Acellular Nerve Grafts using Nerve Growth Factor
∙ ∙
Not a clinical study v Fernando Ovalle, Jr., BA Ashit Patel, MBChB, MRCS Jorge De la Torre, MD Luis O. Vasconez, MD Bruce Shack, MD Wesley P. Thayer, MD, PhD
):105)&4*4 Improving axonal regeneration may lead to improved outcomes for patients with peripheral nerve injury. The use of nerve grafts in which growth inhibitors have been removed with chondroitinase has been well-documented [1-3]; however, less is known about the ability of well-defined neurotrophic factors to enhance axonal regeneration. This study evaluates a simple technique of doping acellular, chondroitinase-treated nerve grafts with nerve growth factor (NGF) and the axonal response of injured nerves to these doped grafts.
v Speaker has nothing of financial value to disclose
∙
Expediting and augmenting axonal ingrowth are important strategies in therapeutic peripheral nerve graft application for improving patient outcome. The described doping technique results in detectable concentrations of NGF in nerve grafts. In a murine sciatic nerve injury model, additional modification of commercially-available chondroitinase-treated, acellular nerve grafts by NGF augmentation provides a simple way to markedly accelerate the ingress of axons. In addition to augmenting axonal ingrowth in these grafts, NGF can preferentially induce smaller caliber axons consistent with sensory axons, a fact which could therapeutically direct selective fiber ingrowth.
3&'&3&/$&4 1. Krekoski CA, Neubauer D, Zuo J, Muir D. Axonal regeneration into acellular nerve grafts is enhanced by degradation of chondroitin sulfate proteoglycan. J Neurosci. 21:6206-13. 2001. 2. Groves ML, McKeon R, Werner E, et al. Axon regeneration in peripheral nerves is enhanced by proteoglycan degradation. Experimental Neurology. 195:278-92. 2005. 3. Neubauer D, Graham JB, Muir, D. Chondroitinase treatment increases the effective length of acellular nerve grafts. Experimental Neurology. 207:163-70. 2007. 4. Yip HK, Rich KM, Lampe PA, Johnson EM Jr. The effects of nerve growth factor and its antiserum on the postnatal development and survival after injury of sensory neurons in rat dorsal root ganglia. J Neurosci 4:2986-2992. 1984. 5. Rich KM, Luszczynski JR, Osborne PA, et al. Nerve growth factor protects adult sensory neurons from cell death and atrophy caused by nerve injury. J Neurocytol 16:261-68. 1987.
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Figure 1. Graphical representation of increase in percentage of NGF detected by ELISA analysis in total protein of acellular, chondroitinasetreated murine nerve grafts after doping with murine NGF at varying concentrations.
Figure 2. Axonal ingrowth throughout graft length in both NGF-treated and control graft groups. Mean axon count ± SEM is plotted at each mm from the proximal repair, demonstrating a higher mean count in the NGF group throughout the length of the grafts. The NGF grafts peak in count at 3mm (1214.2 axons) versus a 4mm (533.1 axons) from proximal repair for the control group.
60
v Speaker has nothing of financial value to disclose
.&5)0%4
According to the findings, MSC treatment has positive effects on both preservation of muscle mass and functional healing following muscle neurotization. The MSC enhance the functional results after NMN and can be used as an alternative to Schwann cells.
Lyophilized chondroitinase-treated murine nerve grafts were doped with varied concentrations of NGF and subsequent ELISA analysis was used to calculate the quantity of NGF present in the grafts. A murine sciatic nerve injury model was used to evaluate the effectiveness of the grafts. Grafts were implanted into 3 experimental (NGF-treated) and 3 control rats for 5 days. Axonal regeneration into the grafts was assessed by immunocytochemical analysis in frozen sections. Digital image analysis was used to characterize and compare the growth-factor induced axons to those in the control grafts. Descriptive statistics including counts, means, and standard error of the mean (+/SEM) were used to summarize data as appropriate. Univariate analysis was performed on axon counts and areas using the Student's t-test for independent samples.
3&46-54
Figure 1
PAPER 69 4BUVSEBZ 4FQUFNCFS t1. $MJOJDBM1BQFS4FTTJPO/FSWF#BTJD3FTFBSDI
A non-linear concentration-dependent loading of our nerve grafts with NGF was demonstrated using this technique (Figure 1). Subsequent analysis of these grafts in our in vivo model showed a higher axon count in the NGF group, consistent throughout the length of the nerve grafts with an average of 1035.9 +/- 41.1 axons versus 552.3 +/- 18.1 axons in the control grafts (P<0.0001) (Figure 2). Although the NGF group displayed a higher axon count per slice, the mean diameter of the individual NGF axons was smaller at 2.40 +/- 0.03 m versus 3.46 +/- 0.06 m for the control grafts (P<0.0001), consistent with induction of sensory axons [4,5].
46.."3:10*/54 ∙
A Simple Technique for Augmentation of Axonal Ingrowth into Chondroitinase Treated Acellular Nerve Grafts using Nerve Growth Factor
∙ ∙
Not a clinical study v Fernando Ovalle, Jr., BA Ashit Patel, MBChB, MRCS Jorge De la Torre, MD Luis O. Vasconez, MD Bruce Shack, MD Wesley P. Thayer, MD, PhD
):105)&4*4 Improving axonal regeneration may lead to improved outcomes for patients with peripheral nerve injury. The use of nerve grafts in which growth inhibitors have been removed with chondroitinase has been well-documented [1-3]; however, less is known about the ability of well-defined neurotrophic factors to enhance axonal regeneration. This study evaluates a simple technique of doping acellular, chondroitinase-treated nerve grafts with nerve growth factor (NGF) and the axonal response of injured nerves to these doped grafts.
v Speaker has nothing of financial value to disclose
∙
Expediting and augmenting axonal ingrowth are important strategies in therapeutic peripheral nerve graft application for improving patient outcome. The described doping technique results in detectable concentrations of NGF in nerve grafts. In a murine sciatic nerve injury model, additional modification of commercially-available chondroitinase-treated, acellular nerve grafts by NGF augmentation provides a simple way to markedly accelerate the ingress of axons. In addition to augmenting axonal ingrowth in these grafts, NGF can preferentially induce smaller caliber axons consistent with sensory axons, a fact which could therapeutically direct selective fiber ingrowth.
3&'&3&/$&4 1. Krekoski CA, Neubauer D, Zuo J, Muir D. Axonal regeneration into acellular nerve grafts is enhanced by degradation of chondroitin sulfate proteoglycan. J Neurosci. 21:6206-13. 2001. 2. Groves ML, McKeon R, Werner E, et al. Axon regeneration in peripheral nerves is enhanced by proteoglycan degradation. Experimental Neurology. 195:278-92. 2005. 3. Neubauer D, Graham JB, Muir, D. Chondroitinase treatment increases the effective length of acellular nerve grafts. Experimental Neurology. 207:163-70. 2007. 4. Yip HK, Rich KM, Lampe PA, Johnson EM Jr. The effects of nerve growth factor and its antiserum on the postnatal development and survival after injury of sensory neurons in rat dorsal root ganglia. J Neurosci 4:2986-2992. 1984. 5. Rich KM, Luszczynski JR, Osborne PA, et al. Nerve growth factor protects adult sensory neurons from cell death and atrophy caused by nerve injury. J Neurocytol 16:261-68. 1987.
59
Figure 1. Graphical representation of increase in percentage of NGF detected by ELISA analysis in total protein of acellular, chondroitinasetreated murine nerve grafts after doping with murine NGF at varying concentrations.
Figure 2. Axonal ingrowth throughout graft length in both NGF-treated and control graft groups. Mean axon count ± SEM is plotted at each mm from the proximal repair, demonstrating a higher mean count in the NGF group throughout the length of the grafts. The NGF grafts peak in count at 3mm (1214.2 axons) versus a 4mm (533.1 axons) from proximal repair for the control group.
60
v Speaker has nothing of financial value to disclose