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Shahemi NH, Mahat MM, Asri NAN, Amir MA, Ab Rahim S, Kasri MA. Application of Conductive Hydrogels on Spinal Cord Injury Repair: A Review. ACS Biomater Sci Eng 2023. [PMID: 37364251 DOI: 10.1021/acsbiomaterials.3c00194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Spinal cord injury (SCI) causes severe motor or sensory damage that leads to long-term disabilities due to disruption of electrical conduction in neuronal pathways. Despite current clinical therapies being used to limit the propagation of cell or tissue damage, the need for neuroregenerative therapies remains. Conductive hydrogels have been considered a promising neuroregenerative therapy due to their ability to provide a pro-regenerative microenvironment and flexible structure, which conforms to a complex SCI lesion. Furthermore, their conductivity can be utilized for noninvasive electrical signaling in dictating neuronal cell behavior. However, the ability of hydrogels to guide directional axon growth to reach the distal end for complete nerve reconnection remains a critical challenge. In this Review, we highlight recent advances in conductive hydrogels, including the incorporation of conductive materials, fabrication techniques, and cross-linking interactions. We also discuss important characteristics for designing conductive hydrogels for directional growth and regenerative therapy. We propose insights into electrical conductivity properties in a hydrogel that could be implemented as guidance for directional cell growth for SCI applications. Specifically, we highlight the practical implications of recent findings in the field, including the potential for conductive hydrogels to be used in clinical applications. We conclude that conductive hydrogels are a promising neuroregenerative therapy for SCI and that further research is needed to optimize their design and application.
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Affiliation(s)
- Nur Hidayah Shahemi
- Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia
| | - Mohd Muzamir Mahat
- Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia
| | - Nurul Ain Najihah Asri
- Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia
| | - Muhammad Abid Amir
- Faculty of Medicine, Sungai Buloh Campus, Universiti Teknologi MARA, 47000 Sungai Buloh, Selangor, Malaysia
| | - Sharaniza Ab Rahim
- Faculty of Medicine, Sungai Buloh Campus, Universiti Teknologi MARA, 47000 Sungai Buloh, Selangor, Malaysia
| | - Mohamad Arif Kasri
- Kulliyyah of Science, International Islamic University Malaysia, 25200 Kuantan, Pahang, Malaysia
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2
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Effectiveness of biomaterial-based combination strategies for spinal cord repair – a systematic review and meta-analysis of preclinical literature. Spinal Cord 2022; 60:1041-1049. [DOI: 10.1038/s41393-022-00811-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 12/13/2022]
Abstract
Abstract
Study design
Systematic review and meta-analysis of preclinical literature.
Objectives
To assess the effects of biomaterial-based combination (BMC) strategies for the treatment of Spinal Cord Injury (SCI), the effects of individual biomaterials in the context of BMC strategies, and the factors influencing their efficacy. To assess the effects of different preclinical testing paradigms in BMC strategies.
Methods
We performed a systematic literature search of Embase, Web of Science and PubMed. All controlled preclinical studies describing an in vivo or in vitro model of SCI that tested a biomaterial in combination with at least one other regenerative strategy (cells, drugs, or both) were included. Two review authors conducted the study selection independently, extracted study characteristics independently and assessed study quality using a modified CAMARADES checklist. Effect size measures were combined using random-effects models and heterogeneity was explored using meta-regression with tau2, I2 and R2 statistics. We tested for small-study effects using funnel plot–based methods.
Results
134 publications were included, testing over 100 different BMC strategies. Overall, treatment with BMC therapies improved locomotor recovery by 25.3% (95% CI, 20.3–30.3; n = 102) and in vivo axonal regeneration by 1.6 SD (95% CI 1.2–2 SD; n = 117) in comparison with injury only controls.
Conclusion
BMC strategies improve locomotor outcomes after experimental SCI. Our comprehensive study highlights gaps in current knowledge and provides a foundation for the design of future experiments.
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Liu D, Shu M, Liu W, Shen Y, Long G, Zhao Y, Hou X, Xiao Z, Dai J, Li X. Binary scaffold facilitates in situ regeneration of axons and neurons for complete spinal cord injury repair. Biomater Sci 2021; 9:2955-2971. [PMID: 33634811 DOI: 10.1039/d0bm02212h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The limited regrowth of transected axons and insufficient regeneration of lost neurons in adult mammals collectively hinder complete spinal cord injury (SCI) repair. Hence, designing an ideal bio-scaffold which could coordinate the regeneration of axons and neurons in situ might be able to effectively facilitate the reconstruction of neural circuits and the recovery of nerve function after complete SCI. In this study, a sponge-like collagen scaffold with good drug release characteristics and good nerve cell compatibility was prepared and used as a drug delivery platform. When doubly modified with Taxol liposomes and collagen-binding neurotrophic factor 3, the scaffold dually alleviated myelin-derived inhibition on neurite outgrowth of neurons and neuronal differentiation of neural stem cells in vitro. Meanwhile, the binary-drug modified scaffold was also able to simultaneously promote both axonal and neuronal regeneration when implanted into a complete transected SCI model. Additionally, the regenerated axons and neurons throughout the lesion site formed extensive synaptic connections. Finally, complete SCI rats that received binary scaffold implantation exhibited optimal neuroelectrophysiological recovery and hindlimb locomotor improvement. Taken together, implantation of the binary scaffold can establish neural bridging networks for functional recovery, representing a clinically promising strategy for complete SCI repair.
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Affiliation(s)
- Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital of Central South University, Changsha, 410008, Hunan Province, China.
| | - Muya Shu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiyuan Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yeyu Shen
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, Hunan Province, China and Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Ge Long
- Department of Anesthesia, the Third Xiangya Hospital of Central South University, Changsha, 410013, China
| | - Yannan Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xianglin Hou
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhifeng Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianwu Dai
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xing Li
- Department of Neurosurgery, Xiangya Hospital of Central South University, Changsha, 410008, Hunan Province, China. and Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, Hunan Province, China and Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
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4
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Houlton J, Abumaria N, Hinkley SFR, Clarkson AN. Therapeutic Potential of Neurotrophins for Repair After Brain Injury: A Helping Hand From Biomaterials. Front Neurosci 2019; 13:790. [PMID: 31427916 PMCID: PMC6688532 DOI: 10.3389/fnins.2019.00790] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/15/2019] [Indexed: 12/17/2022] Open
Abstract
Stroke remains the leading cause of long-term disability with limited options available to aid in recovery. Significant effort has been made to try and minimize neuronal damage following stroke with use of neuroprotective agents, however, these treatments have yet to show clinical efficacy. Regenerative interventions have since become of huge interest as they provide the potential to restore damaged neural tissue without being limited by a narrow therapeutic window. Neurotrophins, such as brain-derived neurotrophic factor (BDNF), and their high affinity receptors are actively produced throughout the brain and are involved in regulating neuronal activity and normal day-to-day function. Furthermore, neurotrophins are known to play a significant role in both protection and recovery of function following neurodegenerative diseases such as stroke and traumatic brain injury (TBI). Unfortunately, exogenous administration of these neurotrophins is limited by a lack of blood-brain-barrier (BBB) permeability, poor half-life, and rapid degradation. Therefore, we have focused this review on approaches that provide a direct and sustained neurotrophic support using pharmacological therapies and mimetics, physical activity, and potential drug delivery systems, including discussion around advantages and limitations for use of each of these systems. Finally, we discuss future directions of biomaterial drug-delivery systems, including the incorporation of heparan sulfate (HS) in conjunction with neurotrophin-based interventions.
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Affiliation(s)
- Josh Houlton
- Brain Health Research Centre, Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Nashat Abumaria
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institute of Brain Science, Fudan University, Shanghai, China
- Department of Laboratory Animal Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Simon F. R. Hinkley
- The Ferrier Research Institute, Victoria University of Wellington, Petone, New Zealand
| | - Andrew N. Clarkson
- Brain Health Research Centre, Department of Anatomy, University of Otago, Dunedin, New Zealand
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5
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Liu S, Chen Z. Employing Endogenous NSCs to Promote Recovery of Spinal Cord Injury. Stem Cells Int 2019; 2019:1958631. [PMID: 31191666 PMCID: PMC6525819 DOI: 10.1155/2019/1958631] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/07/2019] [Indexed: 12/15/2022] Open
Abstract
Endogenous neural stem cells (NSCs) exist in the central canal of mammalian spinal cords. Under normal conditions, these NSCs remain quiescent and express FoxJ1. After spinal cord injury (SCI), the endogenous NSCs of a heterogeneous nature are activated and proliferate and migrate towards the lesion site and mainly differentiate into astrocytes to repair the injured tissue. In vitro, spinal cord NSCs are multipotent and can differentiate into neurons, astrocytes, and oligodendrocytes. The altered microenvironments after SCI play key roles on the fate determination of activated NSCs, especially on the neuronal specification potential. Studies show that the activated spinal cord NSCs can generate interneurons when transplanted into the adult hippocampus. In addition, the spinal cord NSCs exhibit low immunogenicity in a transplantation context, thus implicating a promising therapeutic potential on SCI recovery. Here, we summarize the characteristics of spinal cord NSCs, especially their properties after injury. With a better understanding of endogenous NSCs under normal and SCI conditions, we may be able to employ endogenous NSCs for SCI repair in the future.
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Affiliation(s)
- Sumei Liu
- Cell Therapy Center, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
- Key Laboratory of Neurodegenerative Diseases, Ministry of Education, Beijing 100053, China
| | - Zhiguo Chen
- Cell Therapy Center, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
- Key Laboratory of Neurodegenerative Diseases, Ministry of Education, Beijing 100053, China
- Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing 100069, China
- Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Beijing 100069, China
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6
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Fujimaki H, Uchida K, Inoue G, Matsushita O, Nemoto N, Miyagi M, Inage K, Takano S, Orita S, Ohtori S, Tanaka K, Sekiguchi H, Takaso M. Polyglycolic acid-collagen tube combined with collagen-binding basic fibroblast growth factor accelerates gait recovery in a rat sciatic nerve critical-size defect model. J Biomed Mater Res B Appl Biomater 2019; 108:326-332. [PMID: 31016841 DOI: 10.1002/jbm.b.34391] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/24/2019] [Accepted: 04/04/2019] [Indexed: 02/03/2023]
Abstract
Several nerve conduits have been investigated for their potential as alternative sources of autografts for bridging neural gaps. However, autologous nerve transplants remain the most effective for nerve repair. We examined clinically approved nerve conduits containing collagen and polyglycolic acid (PGA-c) combined with collagen-binding basic fibroblast growth factor (bFGF) containing a polycystic kidney disease (PKD) domain and collagen binding domain (CBD) (bFGF-PKD-CBD) in a rat 15-mm sciatic nerve critical-size defect model. The treatment groups were: PGA-c immersed in phosphate-buffered saline (PBS) (PGA-c/PBS group), bFGF (PGA-c/bFGF group), or bFGF-PKD-CBD (PGA-c/bFGF-PKD-CBD group), and no treatment (Defect group). Gait and histological analyses were performed. Four weeks after treatment, the recovery rate of the paw print area was significantly greater in the PGA-c/bFGFPKD-CBD group than the PGA-c/PBS and PGA-c/bFGF groups. Mean intensity of paw prints was significantly greater in the PGA-c/bFGF-PKD-CBD group than the PGA-c/PBS and Defect groups. Swing time was significantly greater in the PGA-c/PBS, PGA-c/bFGF, and PGA-c/bFGF-PKD-CBD groups than the Defect group. At 8 weeks, all three parameters were significantly greater in the PGA-c/PBS, PGA-c/bFGF, and PGA-c/bFGF-PKD-CBD groups than the Defect group. Regenerated myelinated fibers were observed in 7/8 (87.5%) rats in the PGA-c/bFGF-PKD-CBD group after 8 weeks, and in 1/8 (12.5%) and 3/8 (37.5%) rats in the PGA-c/PBS and PGA-c/bFGF groups, respectively. PGA-c/bFGF-PKD-CBD composites may be promising biomaterials for promoting functional recovery of long-distance peripheral nerve defects in clinical practice.
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Affiliation(s)
- Hisako Fujimaki
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Kentaro Uchida
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Gen Inoue
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Osamu Matsushita
- Research Center for Biological Imaging, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Noriko Nemoto
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Masayuki Miyagi
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Kazuhide Inage
- Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Shotaro Takano
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Sumihisa Orita
- Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Seiji Ohtori
- Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Keisuke Tanaka
- Nippi Research Institute of Biomatrix and Protein Engineering Project, 520-11, Toride, Japan
| | - Hiroyuki Sekiguchi
- Shonan University of Medical Sciences Research Institute, Chigasaki City, Kanagawa, Japan
| | - Masashi Takaso
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
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7
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Li X, Liu D, Xiao Z, Zhao Y, Han S, Chen B, Dai J. Scaffold-facilitated locomotor improvement post complete spinal cord injury: Motor axon regeneration versus endogenous neuronal relay formation. Biomaterials 2019; 197:20-31. [PMID: 30639547 DOI: 10.1016/j.biomaterials.2019.01.012] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/10/2018] [Accepted: 01/05/2019] [Indexed: 01/18/2023]
Abstract
Complete transected spinal cord injury (SCI) severely influences the quality of life and mortality rates of animals and patients. In the past decade, many simple and combinatorial therapeutic treatments have been tested in improving locomotor function in animals with this extraordinarily challenging SCI. The potential mechanism for promotion of locomotor function relies either on direct motor axon regeneration through the lesion gap or indirect neuronal relay bridging to functionally reconnect transected spinal stumps. In this review, we first compare the advantages and problems of complete transection SCI animal models with other prevailing SCI models used in motor axon regeneration research. Next, we enumerate some of the popular bio-scaffolds utilized in complete SCI repair in the last decade. Then, the current state of motor axon regeneration as well as its role on locomotor improvement of animals after complete SCI is discussed. Last, the current approach of directing endogenous neuronal relays formation to achieve motor function recovery by well-designed functional bio-scaffolds implantation in complete transected SCI animals is reviewed. Although facilitating neuronal relays formation by bio-scaffolds implantation appears to be more practical and feasible than directing motor axon regeneration in promoting locomotor outcome in animals after complete SCI, there are still challenges in neuronal relays formation, maintaining and debugging for spinal cord regenerative repair.
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Affiliation(s)
- Xing Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Xiangya Hospital, Central South University (CSU), Changsha, Hunan, 410008, China
| | - Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, Hunan Province, China
| | - Zhifeng Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yannan Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Sufang Han
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bing Chen
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianwu Dai
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
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Dumont CM, Munsell MK, Carlson MA, Cummings BJ, Anderson AJ, Shea LD. Spinal Progenitor-Laden Bridges Support Earlier Axon Regeneration Following Spinal Cord Injury. Tissue Eng Part A 2018; 24:1588-1602. [PMID: 30215293 DOI: 10.1089/ten.tea.2018.0053] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
IMPACT STATEMENT Spinal cord injury (SCI) results in loss of tissue innervation below the injury. Spinal progenitors have a greater ability to repair the damage and can be injected into the injury, but their regenerative potential is hampered by their poor survival after transplantation. Biomaterials can create a cell delivery platform and generate a more hospitable microenvironment for the progenitors within the injury. In this work, polymeric bridges are used to deliver embryonic spinal progenitors to the injury, resulting in increased progenitor survival and subsequent regeneration and functional recovery, thus demonstrating the importance of combined therapeutic approaches for SCI.
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Affiliation(s)
- Courtney M Dumont
- 1 Department of Biomedical Engineering, University of Michigan , Ann Arbor, Michigan
| | - Mary K Munsell
- 1 Department of Biomedical Engineering, University of Michigan , Ann Arbor, Michigan
| | - Mitchell A Carlson
- 1 Department of Biomedical Engineering, University of Michigan , Ann Arbor, Michigan
| | - Brian J Cummings
- 2 Institute for Memory Impairments and Neurological Disorders (iMIND), University of California , Irvine, California.,3 Sue and Bill Gross Stem Cell Research Center, University of California , Irvine, California.,4 Department of Anatomy and Neurobiology and University of California , Irvine, California.,5 Department of Physical Medicine and Rehabilitation, University of California , Irvine, California
| | - Aileen J Anderson
- 2 Institute for Memory Impairments and Neurological Disorders (iMIND), University of California , Irvine, California.,3 Sue and Bill Gross Stem Cell Research Center, University of California , Irvine, California.,4 Department of Anatomy and Neurobiology and University of California , Irvine, California.,5 Department of Physical Medicine and Rehabilitation, University of California , Irvine, California
| | - Lonnie D Shea
- 1 Department of Biomedical Engineering, University of Michigan , Ann Arbor, Michigan.,6 Department of Chemical Engineering, University of Michigan , Ann Arbor, Michigan
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9
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Biomaterial Scaffolds in Regenerative Therapy of the Central Nervous System. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7848901. [PMID: 29805977 PMCID: PMC5899851 DOI: 10.1155/2018/7848901] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 02/18/2018] [Accepted: 02/21/2018] [Indexed: 02/08/2023]
Abstract
The central nervous system (CNS) is the most important section of the nervous system as it regulates the function of various organs. Injury to the CNS causes impairment of neurological functions in corresponding sites and further leads to long-term patient disability. CNS regeneration is difficult because of its poor response to treatment and, to date, no effective therapies have been found to rectify CNS injuries. Biomaterial scaffolds have been applied with promising results in regeneration medicine. They also show great potential in CNS regeneration for tissue repair and functional recovery. Biomaterial scaffolds are applied in CNS regeneration predominantly as hydrogels and biodegradable scaffolds. They can act as cellular supportive scaffolds to facilitate cell infiltration and proliferation. They can also be combined with cell therapy to repair CNS injury. This review discusses the categories and progression of the biomaterial scaffolds that are applied in CNS regeneration.
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10
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Lee YS, Wu S, Arinzeh TL, Bunge MB. Transplantation of Schwann Cells Inside PVDF-TrFE Conduits to Bridge Transected Rat Spinal Cord Stumps to Promote Axon Regeneration Across the Gap. J Vis Exp 2017. [PMID: 29155759 DOI: 10.3791/56077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Among various models for spinal cord injury in rats, the contusion model is the most often used because it is the most common type of human spinal cord injury. The complete transection model, although not as clinically relevant as the contusion model, is the most rigorous method to evaluate axon regeneration. In the contusion model, it is difficult to distinguish regenerated from sprouted or spared axons due to the presence of remaining tissue post injury. In the complete transection model, a bridging method is necessary to fill the gap and create continuity from the rostral to the caudal stumps in order to evaluate the effectiveness of the treatments. A reliable bridging surgery is essential to test outcome measures by reducing the variability due to the surgical method. The protocols described here are used to prepare Schwann cells (SCs) and conduits prior to transplantation, complete transection of the spinal cord at thoracic level 8 (T8), insert the conduit, and transplant SCs into the conduit. This approach also uses in situ gelling of an injectable basement membrane matrix with SC transplantation that allows improved axon growth across the rostral and caudal interfaces with the host tissue.
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Affiliation(s)
- Yee-Shuan Lee
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine
| | - Siliang Wu
- Department of Materials Science and Engineering, New Jersey Institute of Technology
| | | | - Mary Bartlett Bunge
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine; Department of Cell Biology, University of Miami Miller School of Medicine; Department of Neurological Surgery, University of Miami Miller School of Medicine;
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11
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Johnson CD, D’Amato AR, Gilbert RJ. Electrospun Fibers for Drug Delivery after Spinal Cord Injury and the Effects of Drug Incorporation on Fiber Properties. Cells Tissues Organs 2016; 202:116-135. [PMID: 27701153 PMCID: PMC5067174 DOI: 10.1159/000446621] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2016] [Indexed: 12/20/2022] Open
Abstract
There is currently no cure for individuals with spinal cord injury (SCI). While many promising approaches are being tested in clinical trials, the complexity of SCI limits several of these approaches from aiding complete functional recovery. Several different categories of biomaterials are investigated for their ability to guide axonal regeneration, to deliver proteins or small molecules locally, or to improve the viability of transplanted stem cells. The purpose of this study is to provide a brief overview of SCI, present the different categories of biomaterial scaffolds that direct and guide axonal regeneration, and then focus specifically on electrospun fiber guidance scaffolds. Much like other polymer guidance approaches, electrospun fibers can retain and deliver therapeutic drugs. The experimental section presents new data showing the incorporation of two therapeutic drugs into electrospun poly-L-lactic acid fibers. Two different concentrations of either riluzole or neurotrophin-3 were loaded into the electrospun fibers to examine the effect of drug concentration on the physical characteristics of the fibers (fiber alignment and fiber diameter). Overall, the drugs were successfully incorporated into the fibers and the release was related to the loading concentration. The fiber diameter decreased with the inclusion of the drug, and the decreased diameter was correlated with a decrease in fiber alignment. Subsequently, the study includes considerations for successful incorporation of a therapeutic drug without changing the physical properties of the fibers.
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Affiliation(s)
- Christopher D.L. Johnson
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180-3590, USA
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY. 12180-3590, USA
| | - Anthony R. D’Amato
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180-3590, USA
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY. 12180-3590, USA
| | - Ryan J. Gilbert
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY, 12180-3590, USA
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY. 12180-3590, USA
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12
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Hanna A, Thompson DL, Hellenbrand DJ, Lee JS, Madura CJ, Wesley MG, Dillon NJ, Sharma T, Enright CJ, Murphy WL. Sustained release of neurotrophin-3 via calcium phosphate-coated sutures promotes axonal regeneration after spinal cord injury. J Neurosci Res 2016; 94:645-52. [DOI: 10.1002/jnr.23730] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 02/17/2016] [Accepted: 02/17/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Amgad Hanna
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
| | - Daniel L. Thompson
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
- Department of Biomedical Engineering; University of Wisconsin; Madison Wisconsin
| | - Daniel J. Hellenbrand
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
- Department of Biomedical Engineering; University of Wisconsin; Madison Wisconsin
| | - Jae-Sung Lee
- Department of Biomedical Engineering; University of Wisconsin; Madison Wisconsin
- Department of Orthopedics and Rehabilitation; University of Wisconsin; Madison Wisconsin
| | - Casey J. Madura
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
| | - Meredith G. Wesley
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
| | - Natalie J. Dillon
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
| | - Tapan Sharma
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
| | - Connor J. Enright
- Department of Neurological Surgery; University of Wisconsin; Madison Wisconsin
| | - William L. Murphy
- Department of Biomedical Engineering; University of Wisconsin; Madison Wisconsin
- Department of Orthopedics and Rehabilitation; University of Wisconsin; Madison Wisconsin
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13
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Functionalized collagen scaffold implantation and cAMP administration collectively facilitate spinal cord regeneration. Acta Biomater 2016; 30:233-245. [PMID: 26593786 DOI: 10.1016/j.actbio.2015.11.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 11/03/2015] [Accepted: 11/14/2015] [Indexed: 01/05/2023]
Abstract
Previous studies have demonstrated that several mechanisms, including numerous inhibitory molecules, weak neurotrophic stimulation and deficient intrinsic regenerative responses, collectively contribute to the failure of mature spinal cord axon regeneration. Thus, combinatorial therapies targeting multiple mechanisms have attracted much attention. In the present study, a porous collagen scaffold was used to support neuronal attachment and bridge axonal regeneration. The scaffold was specifically functionalized using neutralizing proteins (CBD-EphA4LBD, CBD-PlexinB1LBD and NEP1-40) and collagen-binding neurotrophic factors (CBD-BDNF and CBD-NT3) to simultaneously antagonize myelin inhibitory molecules (ephrinB3, Sema4D and Nogo) and exert neurotrophic protection and stimulation. Cerebellar granular neurons cultured on the functionalized collagen scaffold promoted neurite outgrowth in the presence of myelin. Furthermore, a full combinatorial treatment comprising functionalized scaffold implantation and cAMP administration was developed to evaluate the synergistic repair ability in a rat T10 complete removal spinal cord injury model. The results showed that full combinatorial therapy exhibited the greatest advantage in reducing the volume of cavitation, facilitating axonal regeneration, and promoting neuronal generation. The newborn neurons generated in the lesion area could form the neuronal relay and enhance the locomotion recovery after severe spinal cord injury. STATEMENT OF SIGNIFICANCE A porous collagen scaffold was specifically functionalized with neutralizing proteins and neurotrophic factors to antagonize the myelin inhibitory molecules and exert neurotrophic protection and stimulation for spinal cord regeneration. Cerebellar granular neurons seeded on the functionalized collagen scaffold showed enhanced neurite outgrowth ability in vitro. The functionalized scaffold implantation combined with cAMP administration exhibited synergistic repair ability for rat T10 complete spinal cord transection injury.
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14
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Jenkins PM, Laughter MR, Lee DJ, Lee YM, Freed CR, Park D. A nerve guidance conduit with topographical and biochemical cues: potential application using human neural stem cells. NANOSCALE RESEARCH LETTERS 2015; 10:972. [PMID: 26071111 PMCID: PMC4469602 DOI: 10.1186/s11671-015-0972-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/03/2015] [Indexed: 05/26/2023]
Abstract
Despite major advances in the pathophysiological understanding of peripheral nerve damage, the treatment of nerve injuries still remains an unmet medical need. Nerve guidance conduits present a promising treatment option by providing a growth-permissive environment that 1) promotes neuronal cell survival and axon growth and 2) directs axonal extension. To this end, we designed an electrospun nerve guidance conduit using a blend of polyurea and poly-caprolactone with both biochemical and topographical cues. Biochemical cues were integrated into the conduit by functionalizing the polyurea with RGD to improve cell attachment. Topographical cues that resemble natural nerve tissue were incorporated by introducing intraluminal microchannels aligned with nanofibers. We determined that electrospinning the polymer solution across a two electrode system with dissolvable sucrose fibers produced a polymer conduit with the appropriate biomimetic properties. Human neural stem cells were cultured on the conduit to evaluate its ability to promote neuronal growth and axonal extension. The nerve guidance conduit was shown to enhance cell survival, migration, and guide neurite extension.
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Affiliation(s)
- Phillip M Jenkins
- />Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, 12800 E. 19th Avenue, Aurora, CO 80045 USA
| | - Melissa R Laughter
- />Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, 12800 E. 19th Avenue, Aurora, CO 80045 USA
| | - David J Lee
- />Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, 12800 E. 19th Avenue, Aurora, CO 80045 USA
| | - Young M Lee
- />Division of Clinical Pharmacology and Toxicology, University of Colorado School of Medicine, 12700 E. 19th Avenue, Aurora, CO 80045 USA
| | - Curt R Freed
- />Division of Clinical Pharmacology and Toxicology, University of Colorado School of Medicine, 12700 E. 19th Avenue, Aurora, CO 80045 USA
| | - Daewon Park
- />Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, 12800 E. 19th Avenue, Aurora, CO 80045 USA
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Li X, Han J, Zhao Y, Ding W, Wei J, Han S, Shang X, Wang B, Chen B, Xiao Z, Dai J. Functionalized Collagen Scaffold Neutralizing the Myelin-Inhibitory Molecules Promoted Neurites Outgrowth in Vitro and Facilitated Spinal Cord Regeneration in Vivo. ACS APPLIED MATERIALS & INTERFACES 2015; 7:13960-13971. [PMID: 26034998 DOI: 10.1021/acsami.5b03879] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Research has demonstrated that many myelin-associated inhibitory molecules jointly contribute to the failure of adult spinal cord regeneration. Therapies comprehensively targeting the multiple inhibitory nature of the injured spinal cord are being concerned. Here, two collagen-binding proteins, CBD-EphA4LBD and CBD-PlexinB1LBD, were constructed, respectively, to neutralize the axon guidance molecules ephrinB3 and sema4D that inhibit the regeneration of nerve fibers. The two neutralizing proteins have proven their ability to specifically bind collagen and to continuously release from collagen scaffolds. They could also promote neurites outgrowth of cerebellar granular neurons and dorsal root ganglion neurons in vitro. Subsequently, the functionalized collagen scaffolds by physically absorbing NEP1-40 and immobilizing CBD-EphA4LBD and CBD-PlexinB1LBD were transplanted into a rat T10 complete spinal cord transection model. Our results showed that rats that received the treatment of transplanting the functionalized collagen scaffold exhibited great advantage on axonal regeneration and locomotion recovery after spinal cord injury.
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Affiliation(s)
- Xing Li
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- §University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jin Han
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yannan Zhao
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenyong Ding
- ‡Department of Biochemistry, Dalian Medical University, Dalian 116044, China
| | - Jianshu Wei
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Sufang Han
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xianping Shang
- ‡Department of Biochemistry, Dalian Medical University, Dalian 116044, China
| | - Bin Wang
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bing Chen
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhifeng Xiao
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianwu Dai
- †State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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Hydrogels and Cell Based Therapies in Spinal Cord Injury Regeneration. Stem Cells Int 2015; 2015:948040. [PMID: 26124844 PMCID: PMC4466497 DOI: 10.1155/2015/948040] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/14/2014] [Indexed: 01/01/2023] Open
Abstract
Spinal cord injury (SCI) is a central nervous system- (CNS-) related disorder for which there is yet no successful treatment. Within the past several years, cell-based therapies have been explored for SCI repair, including the use of pluripotent human stem cells, and a number of adult-derived stem and mature cells such as mesenchymal stem cells, olfactory ensheathing cells, and Schwann cells. Although promising, cell transplantation is often overturned by the poor cell survival in the treatment of spinal cord injuries. Alternatively, the therapeutic role of different cells has been used in tissue engineering approaches by engrafting cells with biomaterials. The latter have the advantages of physically mimicking the CNS tissue, while promoting a more permissive environment for cell survival, growth, and differentiation. The roles of both cell- and biomaterial-based therapies as single therapeutic approaches for SCI repair will be discussed in this review. Moreover, as the multifactorial inhibitory environment of a SCI suggests that combinatorial approaches would be more effective, the importance of using biomaterials as cell carriers will be herein highlighted, as well as the recent advances and achievements of these promising tools for neural tissue regeneration.
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Xue S, Wu G, Zhang HT, Guo YW, Zou YX, Zhou ZJ, Jiang XD, Ke YQ, Xu RX. Transplantation of Adipocyte-Derived Stem Cells in a Hydrogel Scaffold for the Repair of Cortical Contusion Injury in Rats. J Neurotrauma 2015; 32:506-15. [PMID: 25225747 DOI: 10.1089/neu.2014.3480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sha Xue
- Department of Neurosurgery, Key Laboratory on Brain Function Repair and Regeneration of Guangdong Province, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Gang Wu
- Cancer Prevention and Treatment Center, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Hong-tian Zhang
- The Affiliated Bayi Brain Hospital, The Military General Hospital of Beijing PLA, Beijing, China
| | - Yan-wu Guo
- Department of Neurosurgery, Key Laboratory on Brain Function Repair and Regeneration of Guangdong Province, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Yu-xi Zou
- Department of Neurosurgery, Key Laboratory on Brain Function Repair and Regeneration of Guangdong Province, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Zhen-jun Zhou
- Department of Neurosurgery, Key Laboratory on Brain Function Repair and Regeneration of Guangdong Province, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Xiao-dan Jiang
- Department of Neurosurgery, Key Laboratory on Brain Function Repair and Regeneration of Guangdong Province, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Yi-quan Ke
- Department of Neurosurgery, Key Laboratory on Brain Function Repair and Regeneration of Guangdong Province, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Ru-xiang Xu
- The Affiliated Bayi Brain Hospital, The Military General Hospital of Beijing PLA, Beijing, China
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Abstract
ABSTRACT Restoration of lost neuronal function after spinal cord injury still remains a considerable challenge for current medicine. Over the last decade, regenerative medicine has recorded rapid and promising advancements in stem cell research, genetic engineering and the progression of new sophisticated biomaterials as well as nanotechnology. This advancement has also been reflected in neural tissue engineering, where, along with the development of a new generation of well-designed biopolymer scaffolds, multifactorial therapeutic strategies are being validated in order to determine the greatest possible repair efficacy of the complex CNS pathophysiology. Much attention is currently focused on the designing of multifunctional polymer scaffolds as systems for targeted drug or gene delivery, electrical stimulation or as substrates creating a special micro-environment, promoting the growth and desired differentiation of various cell lines. In this review, the latest advances in biomaterial technology together with various combinatorial strategies designed to treat spinal cord injury treatment are summarized and discussed.
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Liu J, Chen P, Wang Q, Chen Y, Yu H, Ma J, Guo M, Piao M, Ren W, Xiang L. Meta analysis of olfactory ensheathing cell transplantation promoting functional recovery of motor nerves in rats with complete spinal cord transection. Neural Regen Res 2014; 9:1850-8. [PMID: 25422649 PMCID: PMC4239777 DOI: 10.4103/1673-5374.143434] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2014] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE: To evaluate the effects of olfactory ensheathing cell transplantation on functional recovery of rats with complete spinal cord transection. DATA SOURCES: A computer-based online search of Medline (1989–2013), Embase (1989–2013), Cochrane library (1989–2013), Chinese Biomedical Literature Database (1989–2013), China National Knowledge Infrastructure (1989–2013), VIP (1989–2013), Wanfang databases (1989–2013) and Chinese Clinical Trial Register was conducted to collect randomized controlled trial data regarding olfactory ensheathing cell transplantation for the treatment of complete spinal cord transection in rats. SELECTION CRITERIA: Randomized controlled trials investigating olfactory ensheathing cell transplantation and other transplantation methods for promoting neurological functional recovery of rats with complete spinal cord transection were included in the analysis. Meta analysis was conducted using RevMan 4.2.2 software. MAIN OUTCOME MEASURES: Basso, Beattie and Bresnahan scores of rats with complete spinal cord transection were evaluated in this study. RESULTS: Six randomized controlled trials with high quality methodology were included. Meta analysis showed that Basso, Beattie and Bresnahan scores were significantly higher in the olfactory ensheathing cell transplantation group compared with the control group (WMD = 3.16, 95% CI (1.68, 4.65); P < 0.00001). CONCLUSION: Experimental studies have shown that olfactory ensheathing cell transplantation can promote the functional recovery of motor nerves in rats with complete spinal cord transection.
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Affiliation(s)
- Jun Liu
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Ping Chen
- Department of Gastroenterology, Taian Central Hospital, Taian, Shandong Province, China
| | - Qi Wang
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Yu Chen
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Haiong Yu
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Junxiong Ma
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Mingming Guo
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Meihui Piao
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Weijian Ren
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
| | - Liangbi Xiang
- Department of Orthopedics, General Hospital of Shenyang Military Command Area of Chinese PLA, Shenyang, Liaoning Province, China
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Abstract
The advent of the cochlear implant is phenomenal because it is the first surgical prosthesis that is capable of restoring one of the senses. The subsequent rapid evolution of cochlear implants through increasing complexity and functionality has been synchronized with the recent advancements in biotechnology. Surface biotechnology has refined cochlear implants by directly influencing the implant–tissue interface. Emerging surface biotechnology strategies are exemplified by nanofibrous polymeric materials, topographical surface modification, conducting polymer coatings, and neurotrophin-eluting implants. Although these novel developments have received individual attention in the recent literature, the time has come to investigate their collective applications to cochlear implants to restore lost hearing.
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21
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Marquardt LM, Sakiyama-Elbert SE. Engineering peripheral nerve repair. Curr Opin Biotechnol 2013; 24:887-92. [PMID: 23790730 DOI: 10.1016/j.copbio.2013.05.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 05/24/2013] [Accepted: 05/27/2013] [Indexed: 01/13/2023]
Abstract
Current approaches for treating peripheral nerve injury have resulted in promising, yet insufficient functional recovery compared to the clinical standard of care, autologous nerve grafts. In order to design a construct that can match the regenerative potential of the autograft, all facets of nerve tissue must be incorporated in a combinatorial therapy. Engineered biomaterial scaffolds in the future will have to promote enhanced regeneration and appropriate reinnervation by targeting the highly sensitive response of regenerating nerves to their surrounding microenvironment.
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Affiliation(s)
- Laura M Marquardt
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA
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22
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Ikeda M, Uemura T, Takamatsu K, Okada M, Kazuki K, Tabata Y, Ikada Y, Nakamura H. Acceleration of peripheral nerve regeneration using nerve conduits in combination with induced pluripotent stem cell technology and a basic fibroblast growth factor drug delivery system. J Biomed Mater Res A 2013; 102:1370-8. [PMID: 23733515 DOI: 10.1002/jbm.a.34816] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 04/02/2013] [Accepted: 05/17/2013] [Indexed: 12/14/2022]
Abstract
Various modifications including addition of Schwann cells or incorporation of growth factors with bioabsorbable nerve conduits have been explored as options for peripheral nerve repair. However, no reports of nerve conduits containing both supportive cells and growth factors have been published as a regenerative therapy for peripheral nerves. In the present study, sciatic nerve gaps in mice were reconstructed in the following groups: nerve conduit alone (control group), nerve conduit coated with induced pluripotent stem cell (iPSc)-derived neurospheres (iPSc group), nerve conduit coated with iPSc-derived neurospheres and basic fibroblast growth factor (bFGF)-incorporated gelatin microspheres (iPSc + bFGF group), and autograft. The fastest functional recovery and the greatest axon regeneration occurred in the autograft group, followed in order by the iPSc + bFGF group, iPSc group, and control group until 12 weeks after reconstruction. Thus, peripheral nerve regeneration using nerve conduits and functional recovery in mice was accelerated by a combination of iPSc-derived neurospheres and a bFGF drug delivery system. The combination of all three fundamental methodologies, iPSc technology for supportive cells, bioabsorbable nerve conduits for scaffolds, and a bFGF drug delivery system for growth factors, was essential for peripheral nerve regenerative therapy.
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Affiliation(s)
- Mikinori Ikeda
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
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23
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McCreedy DA, Sakiyama-Elbert SE. Combination therapies in the CNS: engineering the environment. Neurosci Lett 2012; 519:115-21. [PMID: 22343313 DOI: 10.1016/j.neulet.2012.02.025] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/03/2012] [Accepted: 02/08/2012] [Indexed: 01/03/2023]
Abstract
The inhibitory extracellular environment that develops in response to traumatic brain injury and spinal cord injury hinders axon growth thereby limiting restoration of function. Several strategies have been developed to engineer a more permissive central nervous system (CNS) environment to promote regeneration and functional recovery. The multi-faced inhibitory nature of the CNS lesion suggests that therapies used in combination may be more effective. In this mini-review we summarize the most recent attempts to engineer the CNS extracellular environment after injury using combinatorial strategies. The advantages and limits of various combination therapies utilizing neurotrophin delivery, cell transplantation, and biomaterial scaffolds are discussed. Treatments that reduce the inhibition by chondroitin sulfate proteoglycans, myelin-associated inhibitors, and other barriers to axon regeneration are also reviewed. Based on the current state of the field, future directions are suggested for research on combination therapies in the CNS.
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Affiliation(s)
- Dylan A McCreedy
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Dr. Box 1097, St. Louis, MO 63130, United States
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