Avoiding scar tissue formation of peripheral nerves with the help of an acellular collagen matrix

PLoS One. 2023 Aug 4;18(8):e0289677. doi: 10.1371/journal.pone.0289677. eCollection 2023.

Abstract

Introduction: Extensive scar tissue formation after peripheral nerve injury or surgery is a common problem. To avoid perineural scarring, implanting a mechanical barrier protecting the nerve from inflammation processes in the perineural environment has shown promising results for functional recovery. This study investigates the potential of an acellular collagen-elastin matrix wrapped around a peripheral nerve after induction of scar tissue formation.

Materials and methods: In the present study, 30 Lewis rats were separated into three groups and sciatic nerve scarring was induced with 2.5% glutaraldehyde (GA-CM) or 2.5% glutaraldehyde with a supplemental FDA-approved acellular collagen-elastin matrix application (GA+CM). Additionally, a sham group was included for control. Nerve regeneration was assessed by functional analysis using the Visual Statisc Sciatic Index (SSI) and MR neurography during the 12-week regeneration period. Histological and histomorphometry analysis were performed to evaluate the degree of postoperative scar tissue formation.

Results: Histological analysis showed an extensive scar tissue formation for GA-CM. Connective tissue ratio was significantly (p < 0.009) reduced for GA+CM (1.347 ± 0.017) compared to GA-CM (1.518 ± 0.057). Similarly, compared to GA+CM, MR-Neurography revealed extensive scar tissue formation for GA-CM with a direct connection between nerve and paraneural environment. Distal to the injury site, quantitative analysis presented significantly higher axon density (p = 0.0145), thicker axon diameter (p = 0.0002) and thicker myelinated fiber thickness (p = 0.0008) for GA+CM compared to GA-CM. Evaluation of functional recovery revealed a significantly faster regeneration for GA+CM.

Conclusion: The supplemental application of an acellular collagen-elastin matrix showed beneficial effects in histological, radiological, and functional analysis. Therefore, applying a collagen-elastin matrix around the nerve after peripheral nerve injury or surgery may have beneficial effects on preventing scar tissue formation in the long run. This represents a feasible approach to avoid scar tissue formation in peripheral nerve surgery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cicatrix* / pathology
  • Cicatrix* / prevention & control
  • Collagen / pharmacology
  • Elastin
  • Glutaral / pharmacology
  • Nerve Regeneration / physiology
  • Peripheral Nerve Injuries* / pathology
  • Peripheral Nerves / pathology
  • Rats
  • Rats, Inbred Lew
  • Rats, Sprague-Dawley
  • Sciatic Nerve / injuries

Substances

  • Elastin
  • Glutaral
  • Collagen

Grants and funding

MedSkin Solutions Dr. Suwelack funded this research. MedSkin Solutions Dr. Suwelack manufactures the collagen matrix (CM) MatriDerm® that was used in this trial. Implants were provided by MedSkin Solutions Dr. Suwelack free of charge. The study was conceived and designed prior to seeking financial support. With respect to this study, MedSkin Solutions Dr. Suwelack was excluded from any aspect of design, conduct, analysis, write up, or publication of the trial. None of the authors has any personal financial ties to MedSkin Solutions Dr. Suwelack. None of the authors received reimbursements, fees, funding, or salary from MedSkin Solutions Dr. Suwelack. None of the authors hold any stocks or shares. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.