1
|
Leckenby J, Sweitzer K, Olsen T, Mayorga-Young D, Milek D, Grobbelaar A. Current Treatments and Future Directions for Facial Paralysis. Facial Plast Surg 2024. [PMID: 38955219 DOI: 10.1055/a-2358-9401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
Abstract
Facial palsy is a condition that affects the facial nerve, the seventh of the 12 cranial nerves. Its main function is to control the muscles of facial expression. This involves the ability to express emotion through controlling the position of the mouth, the eyebrow, nostrils, and eye closure. The facial nerve also plays a key role in maintaining the posture of the mouth and as such, people with facial paralysis often have problems with drooling, speech, and dental hygiene.Due to the devastating effects on the quality of life of individuals with facial palsy, there are a multitude of various treatment options for the paralyzed face. This article reviews current management strategies and points towards promising future directions for research in the field of facial reanimation.
Collapse
Affiliation(s)
- Jonathan Leckenby
- Division of Plastic Surgery, Department of Surgery, University of Rochester, Rochester, New York, New York
- Department of Plastic and Reconstructive Surgery, Great Ormond Street Hospital for Sick Children, London, United Kingdom
| | - Keith Sweitzer
- Division of Plastic Surgery, Department of Surgery, University of Rochester, Rochester, New York, New York
| | - Timothy Olsen
- Division of Plastic Surgery, Department of Surgery, University of Rochester, Rochester, New York, New York
| | - Danielle Mayorga-Young
- Division of Plastic Surgery, Department of Surgery, University of Rochester, Rochester, New York, New York
| | - David Milek
- Division of Plastic Surgery, Department of Surgery, University of Rochester, Rochester, New York, New York
| | - Adriaan Grobbelaar
- Department of Plastic and Reconstructive Surgery, Great Ormond Street Hospital for Sick Children, London, United Kingdom
- Department for Plastic and Hand Surgery, Inselspital University Hospital Bern, University of Bern, Bern, Switzerland
| |
Collapse
|
2
|
Burrell JC, Das S, Laimo FA, Katiyar KS, Browne KD, Shultz RB, Tien VJ, Vu PT, Petrov D, Ali ZS, Rosen JM, Cullen DK. Engineered neuronal microtissue provides exogenous axons for delayed nerve fusion and rapid neuromuscular recovery in rats. Bioact Mater 2022; 18:339-353. [PMID: 35415305 PMCID: PMC8965778 DOI: 10.1016/j.bioactmat.2022.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/18/2022] [Accepted: 03/11/2022] [Indexed: 11/24/2022] Open
Abstract
Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons can re-route local axon fascicles to the target muscle, there are no technologies to provide an exogenous source of axons without sacrificing healthy nerves. Accordingly, we have developed tissue engineered neuromuscular interfaces (TE-NMIs) as the first injectable microtissue containing motor and sensory neurons in an anatomically-inspired architecture. TE-NMIs provide axon tracts that are intended to integrate with denervated distal structures and preserve regenerative capacity during prolonged periods without host innervation. Following implant, we found that TE-NMI axons promoted Schwann cell maintenance, integrated with distal muscle, and preserved an evoked muscle response out to 20-weeks post nerve transection in absence of innervation from host axons. By repopulating the distal sheath with exogenous axons, TE-NMIs also enabled putative delayed fusion with proximal host axons, a phenomenon previously not achievable in delayed repair scenarios due to distal axon degeneration. Here, we found immediate electrophysiological recovery after fusion with proximal host axons and improved axon maturation and muscle reinnervation at 24-weeks post-transection (4-weeks following delayed nerve fusion). These findings show that TE-NMIs provide the potential to improve functional recovery following delayed nerve repair.
Collapse
Affiliation(s)
- Justin C. Burrell
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
| | - Suradip Das
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
| | - Franco A. Laimo
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
| | - Kritika S. Katiyar
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Axonova Medical, LLC, Philadelphia, PA, USA
| | - Kevin D. Browne
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
| | - Robert B. Shultz
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Axonova Medical, LLC, Philadelphia, PA, USA
| | - Vishal J. Tien
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
| | - Phuong T. Vu
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
| | - Dmitriy Petrov
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Zarina S. Ali
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph M. Rosen
- Dartmouth-Hitchcock Medical Center, Division of Plastic Surgery, Dartmouth College, Lebanon, NH, USA
| | - D. Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, 19104, USA
- Axonova Medical, LLC, Philadelphia, PA, USA
| |
Collapse
|
3
|
Petrov D, Burrell JC, Browne KD, Laimo FA, Roberts SE, Ali ZS, Cullen DK. Neurorrhaphy in Presence of Polyethylene Glycol Enables Immediate Electrophysiological Conduction in Porcine Model of Facial Nerve Injury. Front Surg 2022; 9:811544. [PMID: 35341161 PMCID: PMC8948462 DOI: 10.3389/fsurg.2022.811544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/24/2022] [Indexed: 01/09/2023] Open
Abstract
Facial nerve trauma often leads to disfiguring facial muscle paralysis. Despite several promising advancements, facial nerve repair procedures often do not lead to complete functional recovery. Development of novel repair strategies requires testing in relevant preclinical models that replicate key clinical features. Several studies have reported that fusogens, such as polyethylene glycol (PEG), can improve functional recovery by enabling immediate reconnection of injured axons; however, these findings have yet to be demonstrated in a large animal model. We first describe a porcine model of facial nerve injury and repair, including the relevant anatomy, surgical approach, and naive nerve morphometry. Next, we report positive findings from a proof-of-concept experiment testing whether a neurorrhaphy performed in conjunction with a PEG solution maintained electrophysiological nerve conduction at an acute time point in a large animal model. The buccal branch of the facial nerve was transected and then immediately repaired by direct anastomosis and PEG application. Immediate electrical conduction was recorded in the PEG-fused nerves (n = 9/9), whereas no signal was obtained in a control cohort lacking calcium chelating agent in one step (n = 0/3) and in the no PEG control group (n = 0/5). Nerve histology revealed putative-fused axons across the repair site, whereas no positive signal was observed in the controls. Rapid electrophysiological recovery following nerve fusion in a highly translatable porcine model of nerve injury supports previous studies suggesting neurorrhaphy supplemented with PEG may be a promising strategy for severe nerve injury. While acute PEG-mediated axon conduction is promising, additional work is necessary to determine if physical axon fusion occurs and the longer-term fate of distal axon segments as related to functional recovery.
Collapse
Affiliation(s)
- Dmitriy Petrov
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Justin C. Burrell
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States
| | - Kevin D. Browne
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Franco A. Laimo
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Sanford E. Roberts
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Zarina S. Ali
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - D. Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States
- *Correspondence: D. Kacy Cullen
| |
Collapse
|
4
|
Van Nest DS, Kahan DM, Ilyas AM. Polyethylene Glycol Fusion of Nerve Injuries: Review of the Technique and Clinical Applicability. J Hand Microsurg 2021; 13:49-54. [PMID: 33867761 PMCID: PMC8041495 DOI: 10.1055/s-0040-1718651] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Traumatic peripheral nerve injuries present a particular challenge to hand surgeons as mechanisms of nerve-healing pose serious limitations to achieving complete functional recovery. The loss of distal axonal segments through Wallerian degeneration results in the loss of neuromuscular junctions and irreversible muscle atrophy. Current methods of repair depend on the outgrowth of proximal nerve fibers following direct end-to-end repair or gap repair techniques. Investigational techniques in nerve repair using polyethylene glycol (PEG) nerve fusion have been shown to bypass Wallerian degeneration by immediately restoring nerve axonal continuity, thus resulting in a rapid and more complete functional recovery. The purpose of this article is to review the current literature surrounding this novel technique for traumatic nerve repair, paying particular attention to the underlying physiology of nerve healing and the current applications of PEG fusion in the laboratory and clinical setting. This article also serves to identify areas of future investigation to further establish validity and feasibility and encourage the translation of PEG fusion into clinical use.
Collapse
Affiliation(s)
- Duncan S. Van Nest
- Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| | - David M. Kahan
- Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| | - Asif M. Ilyas
- Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| |
Collapse
|
5
|
Ghergherehchi CL, Shores JT, Alderete J, Weitzel EK, Bittner GD. Methylene blue enhances polyethylene glycol-fusion repair of completely severed rat sciatic nerves. Neural Regen Res 2021; 16:2056-2063. [PMID: 33642394 PMCID: PMC8343334 DOI: 10.4103/1673-5374.308099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Complete transection of peripheral mixed nerves immediately produces loss of sensory perception, muscle contractions and voluntary behavior mediated by the severed distal axons. In contrast to natural regeneration (~1 mm/d) of proximal axons that may eventually reinnervate denervated targets, re-innervation is restored within minutes by PEG-fusion that consists of neurorrhaphy and a sequence of well specified hypo- and isotonic calcium-free or calcium-containing solutions, the anti-oxidant methylene blue (MB) and the membrane fusogen polyethylene glycol (PEG). In this study, we examined the relative efficacy of PEG-fusion with no MB (0%), 0.5% MB, or 1% MB on the recovery of voluntary behaviors by female Sprague-Dawley rats with a complete mid-thigh severance of their sciatic nerve bathed in extracellular fluid or calcium-containing isotonic saline. The recovery of voluntary behaviors is the most relevant measure of success of any technique to repair peripheral nerve injuries. We assessed recovery by the sciatic functional index, a commonly used measure of voluntary hindlimb behaviors following complete sciatic transections. We reported that both 1% MB and 0.5% MB in sterile distilled water in our PEG-fusion protocol with neurorrhaphy significantly increased the rate and extent of behavioral recovery compared to PEG plus neurorrhaphy alone. Furthermore, 0.5% MB was as effective as 1% MB in voluntary behavioral recovery as assessed by the sciatic functional index. Since sterile 1% MB is no longer clinically available, we therefore recommend that 0.5% MB be included in upcoming human clinical trials to evaluate the safety and efficacy of PEG-fusion. All animal procedures were approved by the University of Texas Institutional Animal Care and Use Committee (AUP-2019-00225) on September 9, 2020.
Collapse
Affiliation(s)
- Cameron L Ghergherehchi
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA
| | - Jaimie T Shores
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Joseph Alderete
- Department of Surgery, RESTOR Laboratory, San Antonio, TX, USA
| | - Erik K Weitzel
- Department of Surgery, RESTOR Laboratory, San Antonio, TX, USA
| | - George D Bittner
- Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| |
Collapse
|
6
|
Brown BL, Asante T, Welch HR, Sandelski MM, Drejet SM, Shah K, Runge EM, Shipchandler TZ, Jones KJ, Walker CL. Functional and Anatomical Outcomes of Facial Nerve Injury With Application of Polyethylene Glycol in a Rat Model. JAMA FACIAL PLAST SU 2020; 21:61-68. [PMID: 29800078 DOI: 10.1001/jamafacial.2018.0308] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Importance Functional and anatomical outcomes after surgical repair of facial nerve injury may be improved with the addition of polyethylene glycol (PEG) to direct suture neurorrhaphy. The application of PEG has shown promise in treating spinal nerve injuries, but its efficacy has not been evaluated in treatment of cranial nerve injuries. Objective To determine whether PEG in addition to neurorrhaphy can improve functional outcomes and synkinesis after facial nerve injury. Design, Setting, and Subjects In this animal experiment, 36 rats underwent right facial nerve transection and neurorrhaphy with addition of PEG. Weekly behavioral scoring was done for 10 rats for 6 weeks and 14 rats for 16 weeks after the operations. In the 16-week study, the buccal branches were labeled and tissue analysis was performed. In the 6-week study, the mandibular and buccal branches were labeled and tissue analysis was performed. Histologic analysis was performed for 10 rats in a 1-week study to assess the association of PEG with axonal continuity and Wallerian degeneration. Six rats served as the uninjured control group. Data were collected from February 8, 2016, through July 10, 2017. Intervention Polyethylene glycol applied to the facial nerve after neurorrhaphy. Main Outcomes and Measures Functional recovery was assessed weekly for the 16- and 6-week studies, as well as motoneuron survival, amount of regrowth, specificity of regrowth, and aberrant branching. Short-term effects of PEG were assessed in the 1-week study. Results Among the 40 male rats included in the study, PEG addition to neurorrhaphy showed no functional benefit in eye blink reflex (mean [SEM], 3.57 [0.88] weeks; 95% CI, -2.8 to 1.9 weeks; P = .70) or whisking function (mean [SEM], 4.00 [0.72] weeks; 95% CI, -3.6 to 2.4 weeks; P = .69) compared with suturing alone at 16 weeks. Motoneuron survival was not changed by PEG in the 16-week (mean, 132.1 motoneurons per tissue section; 95% CI, -21.0 to 8.4; P = .13) or 6-week (mean, 131.1 motoneurons per tissue section; 95% CI, -11.0 to 10.0; P = .06) studies. Compared with controls, neither surgical group showed differences in buccal branch regrowth at 16 (36.9 motoneurons per tissue section; 95% CI, -14.5 to 22.0; P = .28) or 6 (36.7 motoneurons per tissue section; 95% CI, -7.8 to 18.5; P = .48) weeks or in the mandibular branch at 6 weeks (25.2 motoneurons per tissue section; 95% CI, -14.5 to 15.5; P = .99). Addition of PEG had no advantage in regrowth specificity compared with suturing alone at 16 weeks (15.3% buccal branch motoneurons with misguided projections; 95% CI, -7.2% to 11.0%; P = .84). After 6 weeks, the number of motoneurons with misguided projections to the mandibular branch showed no advantage of PEG treatment compared with suturing alone (12.1% buccal branch motoneurons with misguided projections; 95% CI, -8.2% to 9.2%; P = .98). In the 1-week study, improved axonal continuity and muscular innervation were not observed in PEG-treated rats. Conclusions and Relevance Although PEG has shown efficacy in treating other nervous system injuries, PEG in addition to neurorraphy was not beneficial in a rat model of facial nerve injury. The addition of PEG to suturing may not be warranted in the surgical repair of facial nerve injury. Level of Evidence NA.
Collapse
Affiliation(s)
- Brandon L Brown
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis.,Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky
| | - Tony Asante
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis
| | - Haley R Welch
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis
| | - Morgan M Sandelski
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis
| | - Sarah M Drejet
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis
| | - Kishan Shah
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis
| | - Elizabeth M Runge
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis
| | - Taha Z Shipchandler
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis
| | - Kathryn J Jones
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis.,Research and Development Service, Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana
| | - Chandler L Walker
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis.,Research and Development Service, Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana.,Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis
| |
Collapse
|
7
|
Amani H, Kazerooni H, Hassanpoor H, Akbarzadeh A, Pazoki-Toroudi H. Tailoring synthetic polymeric biomaterials towards nerve tissue engineering: a review. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2020; 47:3524-3539. [PMID: 31437011 DOI: 10.1080/21691401.2019.1639723] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The nervous system is known as a crucial part of the body and derangement in this system can cause potentially lethal consequences or serious side effects. Unfortunately, the nervous system is unable to rehabilitate damaged regions following seriously debilitating disorders such as stroke, spinal cord injury and brain trauma which, in turn, lead to the reduction of quality of life for the patient. Major challenges in restoring the damaged nervous system are low regenerative capacity and the complexity of physiology system. Synthetic polymeric biomaterials with outstanding properties such as excellent biocompatibility and non-immunogenicity find a wide range of applications in biomedical fields especially neural implants and nerve tissue engineering scaffolds. Despite these advancements, tailoring polymeric biomaterials for design of a desired scaffold is fundamental issue that needs tremendous attention to promote the therapeutic benefits and minimize adverse effects. This review aims to (i) describe the nervous system and related injuries. Then, (ii) nerve tissue engineering strategies are discussed and (iii) physiochemical properties of synthetic polymeric biomaterials systematically highlighted. Moreover, tailoring synthetic polymeric biomaterials for nerve tissue engineering is reviewed.
Collapse
Affiliation(s)
- Hamed Amani
- Department of Medical Nanotechnology, Faculty of Advanced Technologies in Medicine, Iran University of Medical Science , Tehran , Iran
| | - Hanif Kazerooni
- Biotechnology Group, Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic) , Tehran , Iran
| | - Hossein Hassanpoor
- Department of Cognitive Science, Dade Pardazi, Shenakht Mehvar, Atynegar (DSA) Institute , Tehran , Iran
| | - Abolfazl Akbarzadeh
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences , Tabriz , Iran
| | - Hamidreza Pazoki-Toroudi
- Physiology Research Center and Department of Physiology, Faculty of Medicine, Iran University of Medical Sciences , Tehran , Iran
| |
Collapse
|
8
|
Ghergherehchi CL, Mikesh M, Sengelaub DR, Jackson DM, Smith T, Nguyen J, Shores JT, Bittner GD. Polyethylene glycol (PEG) and other bioactive solutions with neurorrhaphy for rapid and dramatic repair of peripheral nerve lesions by PEG-fusion. J Neurosci Methods 2018; 314:1-12. [PMID: 30586569 DOI: 10.1016/j.jneumeth.2018.12.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/17/2018] [Accepted: 12/19/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Nervous system injuries in mammals often involve transection or segmental loss of peripheral nerves. Such injuries result in functional (behavioral) deficits poorly restored by naturally occurring 1-2 mm/d axonal outgrowths aided by primary repair or reconstruction. "Neurorrhaphy" or nerve repair joins severed connective tissues, but not severed cytoplasmic/plasmalemmal extensions (axons) within the tissue. NEW METHOD PEG-fusion consists of neurorrhaphy combined with a well-defined sequence of four pharmaceutical agents in solution, one containing polyethylene glycol (PEG), applied directly to closely apposed viable ends of severed axons. RESULTS PEG-fusion of rat sciatic nerves: (1) restores axonal continuity across coaptation site(s) within minutes, (2) prevents Wallerian degeneration of many distal severed axons, (3) preserves neuromuscular junctions, (4) prevents target muscle atrophy, (5) produces rapid and improved recovery of voluntary behaviors compared with neurorrhaphy alone, and (6) PEG-fused allografts are not rejected, despite no tissue-matching nor immunosuppression. COMPARISON WITH EXISTING METHODS If PEG-fusion protocols are not correctly executed, the results are similar to that of neurorrhaphy alone: (1) axonal continuity across coaptation site(s) is not re-established, (2) Wallerian degeneration of all distal severed axons rapidly occurs, (3) neuromuscular junctions are non-functional, (4) target muscle atrophy begins within weeks, (5) recovery of voluntary behavior occurs, if ever, after months to levels well-below that observed in unoperated animals, and (6) allografts are either rejected or not well-accepted. CONCLUSION PEG-fusion produces rapid and dramatic recovery of function following rat peripheral nerve injuries.
Collapse
Affiliation(s)
| | - Michelle Mikesh
- Department of Neuroscience, University of Texas at Austin, Austin, TX, 78712, USA.
| | - Dale R Sengelaub
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
| | | | - Tyler Smith
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
| | - Jacklyn Nguyen
- Department of Neuroscience, University of Texas at Austin, Austin, TX, 78712, USA.
| | - Jaimie T Shores
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, Johns Hopkins University School of Medicine, Ross Research Building 749D, 720 Rutland Avenue, Baltimore, MD, 21205, USA.
| | - George D Bittner
- Department of Neuroscience, University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
9
|
Yi S, Xu L, Gu X. Scaffolds for peripheral nerve repair and reconstruction. Exp Neurol 2018; 319:112761. [PMID: 29772248 DOI: 10.1016/j.expneurol.2018.05.016] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 05/05/2018] [Accepted: 05/13/2018] [Indexed: 12/22/2022]
Abstract
Trauma-associated peripheral nerve defect is a widespread clinical problem. Autologous nerve grafting, the current gold standard technique for the treatment of peripheral nerve injury, has many internal disadvantages. Emerging studies showed that tissue engineered nerve graft is an effective substitute to autologous nerves. Tissue engineered nerve graft is generally composed of neural scaffolds and incorporating cells and molecules. A variety of biomaterials have been used to construct neural scaffolds, the main component of tissue engineered nerve graft. Synthetic polymers (e.g. silicone, polyglycolic acid, and poly(lactic-co-glycolic acid)) and natural materials (e.g. chitosan, silk fibroin, and extracellular matrix components) are commonly used along or together to build neural scaffolds. Many other materials, including the extracellular matrix, glass fabrics, ceramics, and metallic materials, have also been used to construct neural scaffolds. These biomaterials are fabricated to create specific structures and surface features. Seeding supporting cells and/or incorporating neurotrophic factors to neural scaffolds further improve restoration effects. Preliminary studies demonstrate that clinical applications of these neural scaffolds achieve satisfactory functional recovery. Therefore, tissue engineered nerve graft provides a good alternative to autologous nerve graft and represents a promising frontier in neural tissue engineering.
Collapse
Affiliation(s)
- Sheng Yi
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Lai Xu
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Xiaosong Gu
- Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China.
| |
Collapse
|
10
|
Mikesh M, Ghergherehchi CL, Hastings RL, Ali A, Rahesh S, Jagannath K, Sengelaub DR, Trevino RC, Jackson DM, Bittner GD. Polyethylene glycol solutions rapidly restore and maintain axonal continuity, neuromuscular structures, and behaviors lost after sciatic nerve transections in female rats. J Neurosci Res 2018; 96:1223-1242. [PMID: 29659058 DOI: 10.1002/jnr.24225] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 12/15/2022]
Abstract
Complete severance of major peripheral mixed sensory-motor nerve proximally in a mammalian limb produces immediate loss of action potential conduction and voluntary behaviors mediated by the severed distal axonal segments. These severed distal segments undergo Wallerian degeneration within days. Denervated muscles atrophy within weeks. Slowly regenerating (∼1 mm/day) outgrowths from surviving proximal stumps that often nonspecifically reinnervate denervated targets produce poor, if any, restoration of lost voluntary behaviors. In contrast, in this study using completely transected female rat sciatic axons as a model system, we provide extensive morphometric, immunohistochemical, electrophysiological, and behavioral data to show that these adverse outcomes are avoided by microsuturing closely apposed axonal cut ends (neurorrhaphy) and applying a sequence of well-specified solutions, one of which contains polyethylene glycol (PEG). This "PEG-fusion" procedure within minutes reestablishes axoplasmic and axolemmal continuity and signaling by nonspecifically fusing (connecting) closely apposed open ends of severed motor and/or sensory axons at the lesion site. These PEG-fused axons continue to conduct action potentials and generate muscle action potentials and muscle twitches for months and do not undergo Wallerian degeneration. Continuously innervated muscle fibers undergo much less atrophy compared with denervated muscle fibers. Dramatic behavioral recovery to near-unoperated levels occurs within days to weeks, almost certainly by activating many central nervous system and peripheral nervous system synaptic and other plasticities, some perhaps to a greater extent than most neuroscientists would expect. Negative control transections in which neurorrhaphy and all solutions except the PEG-containing solution are applied produce none of these remarkably fortuitous outcomes observed for PEG-fusion.
Collapse
Affiliation(s)
- Michelle Mikesh
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
| | | | | | - Amir Ali
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
| | - Sina Rahesh
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
| | - Karthik Jagannath
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
| | - Dale R Sengelaub
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana
| | - Richard C Trevino
- Department of Orthopedic Surgery, Wellspan Teaching Hospitals, York, Pennsylvania
| | | | - George D Bittner
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
| |
Collapse
|
11
|
Mikesh M, Ghergherehchi CL, Rahesh S, Jagannath K, Ali A, Sengelaub DR, Trevino RC, Jackson DM, Tucker HO, Bittner GD. Polyethylene glycol treated allografts not tissue matched nor immunosuppressed rapidly repair sciatic nerve gaps, maintain neuromuscular functions, and restore voluntary behaviors in female rats. J Neurosci Res 2018; 96:1243-1264. [PMID: 29659046 DOI: 10.1002/jnr.24227] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 02/05/2023]
Abstract
Many publications report that ablations of segments of peripheral nerves produce the following unfortunate results: (1) Immediate loss of sensory signaling and motor control; (2) rapid Wallerian degeneration of severed distal axons within days; (3) muscle atrophy within weeks; (4) poor behavioral (functional) recovery after many months, if ever, by slowly-regenerating (∼1mm/d) axon outgrowths from surviving proximal nerve stumps; and (5) Nerve allografts to repair gap injuries are rejected, often even if tissue matched and immunosuppressed. In contrast, using a female rat sciatic nerve model system, we report that neurorrhaphy of allografts plus a well-specified-sequence of solutions (one containing polyethylene glycol: PEG) successfully addresses each of these problems by: (a) Reestablishing axonal continuity/signaling within minutes by nonspecific ally PEG-fusing (connecting) severed motor and sensory axons across each anastomosis; (b) preventing Wallerian degeneration by maintaining many distal segments of inappropriately-reconnected, PEG-fused axons that continuously activate nerve-muscle junctions; (c) maintaining innervation of muscle fibers that undergo much less atrophy than otherwise-denervated muscle fibers; (d) inducing remarkable behavioral recovery to near-unoperated levels within days to weeks, almost certainly by CNS and PNS plasticities well-beyond what most neuroscientists currently imagine; and (e) preventing rejection of PEG-fused donor nerve allografts with no tissue matching or immunosuppression. Similar behavioral results are produced by PEG-fused autografts. All results for Negative Control allografts agree with current neuroscience data 1-5 given above. Hence, PEG-fusion of allografts for repair of ablated peripheral nerve segments expand on previous observations in single-cut injuries, provoke reconsideration of some current neuroscience dogma, and further extend the potential of PEG-fusion in clinical practice.
Collapse
Affiliation(s)
- Michelle Mikesh
- Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Cameron L Ghergherehchi
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Sina Rahesh
- Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Karthik Jagannath
- Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Amir Ali
- Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Dale R Sengelaub
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, 47405, USA
| | - Richard C Trevino
- Department of Orthopedic Surgery, Wellspan Teaching Hospitals, York, PA, USA
| | | | - Haley O Tucker
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, 78712, USA
| | - George D Bittner
- Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| |
Collapse
|
12
|
Bittner GD, Sengelaub DR, Ghergherehchi CL. Conundrums and confusions regarding how polyethylene glycol-fusion produces excellent behavioral recovery after peripheral nerve injuries. Neural Regen Res 2018; 13:53-57. [PMID: 29451204 PMCID: PMC5840989 DOI: 10.4103/1673-5374.224363] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Current Neuroscience dogma holds that transections or ablations of a segment of peripheral nerves produce: (1) Immediate loss of axonal continuity, sensory signaling, and motor control; (2) Wallerian rapid (1–3 days) degeneration of severed distal axons, muscle atrophy, and poor behavioral recovery after many months (if ever, after ablations) by slowly-regenerating (1 mm/d), proximal-stump outgrowths that must specifically reinnervate denervated targets; (3) Poor acceptance of microsutured nerve allografts, even if tissue-matched and immune-suppressed. Repair of transections/ablations by neurorrhaphy and well-specified-sequences of PEG-fusion solutions (one containing polyethylene glycol, PEG) successfully address these problems. However, conundrums and confusions regarding unorthodox and dramatic results of PEG-fusion repair in animal model systems often lead to misunderstandings. For example, (1) Axonal continuity and signaling is re-established within minutes by non-specifically PEG-fusing (connecting) severed motor and sensory axons across each lesion site, but remarkable behavioral recovery to near-unoperated levels takes several weeks; (2) Many distal stumps of inappropriately-reconnected, PEG-fused axons do not ever (Wallerian) degenerate and continuously innervate muscle fibers that undergo much less atrophy than otherwise-denervated muscle fibers; (3) Host rats do not reject PEG-fused donor nerve allografts in a non-immuno-privileged environment with no tissue matching or immunosuppression; (4) PEG fuses apposed open axonal ends or seals each shut (thereby preventing PEG-fusion), depending on the experimental protocol; (5) PEG-fusion protocols produce similar results in animal model systems and early human case studies. Hence, iconoclastic PEG-fusion data appropriately understood might provoke a re-thinking of some Neuroscience dogma and a paradigm shift in clinical treatment of peripheral nerve injuries.
Collapse
Affiliation(s)
- George D Bittner
- Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Dale R Sengelaub
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | | |
Collapse
|