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Zhang Q, Shi B, Ding J, Yan L, Thawani JP, Fu C, Chen X. Polymer scaffolds facilitate spinal cord injury repair. Acta Biomater 2019; 88:57-77. [PMID: 30710714 DOI: 10.1016/j.actbio.2019.01.056] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/10/2019] [Accepted: 01/28/2019] [Indexed: 12/23/2022]
Abstract
During the past decades, improving patient neurological recovery following spinal cord injury (SCI) has remained a challenge. An effective treatment for SCI would not only reduce fractured elements and isolate developing local glial scars to promote axonal regeneration but also ameliorate secondary effects, including inflammation, apoptosis, and necrosis. Three-dimensional (3D) scaffolds provide a platform in which these mechanisms can be addressed in a controlled manner. Polymer scaffolds with favorable biocompatibility and appropriate mechanical properties have been engineered to minimize cicatrization, customize drug release, and ensure an unobstructed space to promote cell growth and differentiation. These properties make polymer scaffolds an important potential therapeutic platform. This review highlights the recent developments in polymer scaffolds for SCI engineering. STATEMENT OF SIGNIFICANCE: How to improve the efficacy of neurological recovery after spinal cord injury (SCI) is always a challenge. Tissue engineering provides a promising strategy for SCI repair, and scaffolds are one of the most important elements in addition to cells and inducing factors. The review highlights recent development and future prospects in polymer scaffolds for SCI therapy. The review will guide future studies by outlining the requirements and characteristics of polymer scaffold technologies employed against SCI. Additionally, the peculiar properties of polymer materials used in the therapeutic process of SCI also have guiding significance to other tissue engineering approaches.
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Biscola NP, Cartarozzi LP, Ulian-Benitez S, Barbizan R, Castro MV, Spejo AB, Ferreira RS, Barraviera B, Oliveira ALR. Multiple uses of fibrin sealant for nervous system treatment following injury and disease. J Venom Anim Toxins Incl Trop Dis 2017; 23:13. [PMID: 28293254 PMCID: PMC5348778 DOI: 10.1186/s40409-017-0103-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/23/2017] [Indexed: 12/14/2022] Open
Abstract
Lesions to the nervous system often produce hemorrhage and tissue loss that are difficult, if not impossible, to repair. Therefore, scar formation, inflammation and cavitation take place, expanding the lesion epicenter. This significantly worsens the patient conditions and impairment, increasing neuronal loss and glial reaction, which in turn further decreases the chances of a positive outcome. The possibility of using hemostatic substances that also function as a scaffold, such as the fibrin sealant, reduces surgical time and improve postoperative recovery. To date, several studies have demonstrated that human blood derived fibrin sealant produces positive effects in different interventions, becoming an efficient alternative to suturing. To provide an alternative to homologous fibrin sealants, the Center for the Study of Venoms and Venomous Animals (CEVAP, Brazil) has proposed a new bioproduct composed of certified animal components, including a thrombin-like enzyme obtained from snake venom and bubaline fibrinogen. Thus, the present review brings up to date literature assessment on the use of fibrin sealant for nervous system repair and positions the new heterologous bioproduct from CEVAP as an alternative to the commercial counterparts. In this way, clinical and pre-clinical data are discussed in different topics, ranging from central nervous system to peripheral nervous system applications, specifying positive results as well as future enhancements that are necessary for improving the use of fibrin sealant therapy.
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Affiliation(s)
- Natalia Perussi Biscola
- Graduate Program in Tropical Diseases, Botucatu Medical School, Univ Estadual Paulista (UNESP), Botucatu, SP Brazil.,Center for the Study of Venoms and Venomous Animals (CEVAP), Univ Estadual Paulista (UNESP), Botucatu, SP Brazil.,Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil
| | - Luciana Politti Cartarozzi
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil
| | - Suzana Ulian-Benitez
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil.,Neuro Development Lab, School of Biosciences, University of Birmingham, Birmingham, England UK
| | - Roberta Barbizan
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil.,The School of Medicine at Mucuri (FAMMUC), Federal University of Jequitinhonha and Mucuri Valleys (UFVJM), 39803-371 Teófilo Otoni, MG Brazil
| | - Mateus Vidigal Castro
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil
| | - Aline Barroso Spejo
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil
| | - Rui Seabra Ferreira
- Graduate Program in Tropical Diseases, Botucatu Medical School, Univ Estadual Paulista (UNESP), Botucatu, SP Brazil.,Center for the Study of Venoms and Venomous Animals (CEVAP), Univ Estadual Paulista (UNESP), Botucatu, SP Brazil
| | - Benedito Barraviera
- Graduate Program in Tropical Diseases, Botucatu Medical School, Univ Estadual Paulista (UNESP), Botucatu, SP Brazil.,Center for the Study of Venoms and Venomous Animals (CEVAP), Univ Estadual Paulista (UNESP), Botucatu, SP Brazil
| | - Alexandre Leite Rodrigues Oliveira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Laboratory of Nerve Regeneration, CEP 13083-970 Campinas, SP Brazil
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Abstract
STUDY DESIGN Laboratory/animal-based proof of principle study. OBJECTIVE To validate the accuracy of a magnetic resonance imaging (MRI)-guided stereotactic system for intraspinal electrode targeting and demonstrate the feasibility of such a system for controlling implantation of intraspinal electrodes. SUMMARY OF BACKGROUND DATA Intraspinal microstimulation (ISMS) is an emerging preclinical therapy, which has shown promise for the restoration of motor function following spinal cord injury. However, targeting inaccuracy associated with existing electrode implantation techniques remains a major barrier preventing clinical translation of ISMS. METHODS System accuracy was evaluated using a test phantom comprised of nine target locations. Targeting accuracy was determined by calculating the root mean square error between MRI-generated coordinates and actual frame coordinates required to reach the target positions. System performance was further validated in an anesthetized pig model by performing MRI-guided intraspinal electrode implantation and stimulation followed by computed tomography of electrode location. Finally, system compatibility with a commercially available microelectrode array was demonstrated by implanting the array and applying a selection of stimulation amplitudes that evoked hind limb responses. RESULTS The root mean square error between actual frame coordinates and software coordinates, both acquired using the test phantom, was 1.09 ± 0.20 mm. Postoperative computed tomography in the anesthetized pig confirmed spatially accurate electrode placement relative to preoperative MRI. Additionally, MRI-guided delivery of a microwire electrode followed by ISMS evoked repeatable electromyography responses in the biceps femoris muscle. Finally, delivery of a microelectrode array produced repeatable and graded hind limb evoked movements. CONCLUSION We present a novel frame-based stereotactic system for targeting and delivery of intraspinal instrumentation. This system utilizes MRI guidance to account for variations in anatomy between subjects, thereby improving upon existing ISMS electrode implantation techniques. LEVEL OF EVIDENCE N/A.
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Mallory GW, Grahn PJ, Hachmann JT, Lujan JL, Lee KH. Optical stimulation for restoration of motor function after spinal cord injury. Mayo Clin Proc 2015; 90:300-7. [PMID: 25659246 PMCID: PMC4339262 DOI: 10.1016/j.mayocp.2014.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 12/31/2022]
Abstract
Spinal cord injury can be defined as a loss of communication between the brain and the body due to disrupted pathways within the spinal cord. Although many promising molecular strategies have emerged to reduce secondary injury and promote axonal regrowth, there is still no effective cure, and recovery of function remains limited. Functional electrical stimulation (FES) represents a strategy developed to restore motor function without the need for regenerating severed spinal pathways. Despite its technological success, however, FES has not been widely integrated into the lives of spinal cord injury survivors. In this review, we briefly discuss the limitations of existing FES technologies. Additionally, we discuss how optogenetics, a rapidly evolving technique used primarily to investigate select neuronal populations within the brain, may eventually be used to replace FES as a form of therapy for functional restoration after spinal cord injury.
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Affiliation(s)
- Grant W Mallory
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN
| | - Peter J Grahn
- Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN
| | - Jan T Hachmann
- School of Medicine, Heidelberg University, Neuenheimer Feld, Bergheim, Germany
| | - J Luis Lujan
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN
| | - Kendall H Lee
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN.
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