1
|
Kolb J, Tsata V, John N, Kim K, Möckel C, Rosso G, Kurbel V, Parmar A, Sharma G, Karandasheva K, Abuhattum S, Lyraki O, Beck T, Müller P, Schlüßler R, Frischknecht R, Wehner A, Krombholz N, Steigenberger B, Beis D, Takeoka A, Blümcke I, Möllmert S, Singh K, Guck J, Kobow K, Wehner D. Small leucine-rich proteoglycans inhibit CNS regeneration by modifying the structural and mechanical properties of the lesion environment. Nat Commun 2023; 14:6814. [PMID: 37884489 PMCID: PMC10603094 DOI: 10.1038/s41467-023-42339-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 10/04/2023] [Indexed: 10/28/2023] Open
Abstract
Extracellular matrix (ECM) deposition after central nervous system (CNS) injury leads to inhibitory scarring in humans and other mammals, whereas it facilitates axon regeneration in the zebrafish. However, the molecular basis of these different fates is not understood. Here, we identify small leucine-rich proteoglycans (SLRPs) as a contributing factor to regeneration failure in mammals. We demonstrate that the SLRPs chondroadherin, fibromodulin, lumican, and prolargin are enriched in rodent and human but not zebrafish CNS lesions. Targeting SLRPs to the zebrafish injury ECM inhibits axon regeneration and functional recovery. Mechanistically, we find that SLRPs confer mechano-structural properties to the lesion environment that are adverse to axon growth. Our study reveals SLRPs as inhibitory ECM factors that impair axon regeneration by modifying tissue mechanics and structure, and identifies their enrichment as a feature of human brain and spinal cord lesions. These findings imply that SLRPs may be targets for therapeutic strategies to promote CNS regeneration.
Collapse
Affiliation(s)
- Julia Kolb
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Biology, Animal Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Vasiliki Tsata
- Experimental Surgery, Clinical and Translational Research Center, Biomedical Research Foundation Academy of Athens, 11527, Athens, Greece
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527, Athens, Greece
| | - Nora John
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Biology, Animal Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Kyoohyun Kim
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Conrad Möckel
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Physics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Gonzalo Rosso
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Veronika Kurbel
- Department of Neuropathology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Asha Parmar
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Physics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Gargi Sharma
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Department of Medicine 1, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Kristina Karandasheva
- Department of Neuropathology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Shada Abuhattum
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Olga Lyraki
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Biology, Animal Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Timon Beck
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Paul Müller
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Raimund Schlüßler
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany
| | - Renato Frischknecht
- Department of Biology, Animal Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Anja Wehner
- Mass Spectrometry Core Facility, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Nicole Krombholz
- Mass Spectrometry Core Facility, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Barbara Steigenberger
- Mass Spectrometry Core Facility, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Dimitris Beis
- Experimental Surgery, Clinical and Translational Research Center, Biomedical Research Foundation Academy of Athens, 11527, Athens, Greece
- Laboratory of Biological Chemistry, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110, Ioannina, Greece
| | - Aya Takeoka
- VIB-Neuroelectronics Research Flanders, 3001, Leuven, Belgium
- Department of Neuroscience and Leuven Brain Institute, KU Leuven, 3000, Leuven, Belgium
| | - Ingmar Blümcke
- Department of Neuropathology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Stephanie Möllmert
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Kanwarpal Singh
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Physics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Jochen Guck
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Physics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Katja Kobow
- Department of Neuropathology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Daniel Wehner
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany.
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany.
| |
Collapse
|
2
|
A Biomimetic Nonwoven-Reinforced Hydrogel for Spinal Cord Injury Repair. Polymers (Basel) 2022; 14:polym14204376. [PMID: 36297954 PMCID: PMC9609830 DOI: 10.3390/polym14204376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/08/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2022] Open
Abstract
In clinical trials, new scaffolds for regeneration after spinal cord injury (SCI) should reflect the importance of a mechanically optimised, hydrated environment. Composite scaffolds of nonwovens, self-assembling peptides (SAPs) and hydrogels offer the ability to mimic native spinal cord tissue, promote aligned tissue regeneration and tailor mechanical properties. This work studies the effects of an aligned electrospun nonwoven of P11-8—enriched poly(ε-caprolactone) (PCL) fibres, integrated with a photo-crosslinked hydrogel of glycidylmethacrylated collagen (collagen-GMA), on neurite extension. Mechanical properties of collagen-GMA hydrogel in compression and shear were recorded, along with cell viability. Collagen-GMA hydrogels showed J-shaped stress–strain curves in compression, mimicking native spinal cord tissue. For hydrogels prepared with a 0.8-1.1 wt.% collagen-GMA concentration, strain at break values were 68 ± 1–81 ± 1% (±SE); maximum stress values were 128 ± 9–311 ± 18 kPa (±SE); and maximum force values were 1.0 ± 0.1–2.5 ± 0.1 N (±SE). These values closely mimicked the compression values for feline and porcine tissue in the literature, especially those for 0.8 wt.%. Complex shear modulus values fell in the range 345–2588 Pa, with the lower modulus hydrogels in the range optimal for neural cell survival and growth. Collagen-GMA hydrogel provided an environment for homogenous and three-dimensional cell encapsulation, and high cell viability of 84 ± 2%. Combination of the aligned PCL/P11-8 electrospun nonwoven and collagen-GMA hydrogel retained fibre alignment and pore structure, respectively, and promoted aligned neurite extension of PC12 cells. Thus, it is possible to conclude that scaffolds with mechanical properties that both closely mimic native spinal cord tissue and are optimal for neural cells can be produced, which also promote aligned tissue regeneration when the benefits of hydrogels and electrospun nonwovens are combined.
Collapse
|
3
|
Marinval N, Chew SY. Mechanotransduction assays for neural regeneration strategies: A focus on glial cells. APL Bioeng 2021; 5:021505. [PMID: 33948526 PMCID: PMC8088332 DOI: 10.1063/5.0037814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 02/19/2021] [Indexed: 01/22/2023] Open
Abstract
Glial cells are mechanosensitive, and thus, engineered systems have taken a step forward to design mechanotransduction platforms in order to impart diverse mechanical stresses to cells. Mechanical strain encountered in the central nervous system can arise from diverse mechanisms, such as tissue reorganization, fluid flow, and axon growth, as well as pathological events including axon swelling or mechanical trauma. Biomechanical relevance of the in vitro mechanical testing requires to be placed in line with the physiological and mechanical changes in central nervous tissues that occur during the progression of neurodegenerative diseases. Mechanotransduction signaling utilized by glial cells and the recent approaches intended to model altered microenvironment adapted to pathological context are discussed in this review. New insights in systems merging substrate's stiffness and topography should be considered for further glial mechanotransduction studies, while testing platforms for drug discoveries promise great advancements in pharmacotherapy. Potential leads and strategies for clinical outcomes are expected to be developed following the exploration of these glial mechanosensitive signaling pathways.
Collapse
Affiliation(s)
- Nicolas Marinval
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459
| | - Sing Yian Chew
- Author to whom correspondence should be addressed: . Tel.: +65 6316 8812. Fax: +65 6794 7553
| |
Collapse
|
4
|
Hussein RK, Mencio CP, Katagiri Y, Brake AM, Geller HM. Role of Chondroitin Sulfation Following Spinal Cord Injury. Front Cell Neurosci 2020; 14:208. [PMID: 32848612 PMCID: PMC7419623 DOI: 10.3389/fncel.2020.00208] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/12/2020] [Indexed: 12/15/2022] Open
Abstract
Traumatic spinal cord injury produces long-term neurological damage, and presents a significant public health problem with nearly 18,000 new cases per year in the U.S. The injury results in both acute and chronic changes in the spinal cord, ultimately resulting in the production of a glial scar, consisting of multiple cells including fibroblasts, macrophages, microglia, and reactive astrocytes. Within the scar, there is an accumulation of extracellular matrix (ECM) molecules—primarily tenascins and chondroitin sulfate proteoglycans (CSPGs)—which are considered to be inhibitory to axonal regeneration. In this review article, we discuss the role of CSPGs in the injury response, especially how sulfated glycosaminoglycan (GAG) chains act to inhibit plasticity and regeneration. This includes how sulfation of GAG chains influences their biological activity and interactions with potential receptors. Comprehending the role of CSPGs in the inhibitory properties of the glial scar provides critical knowledge in the much-needed production of new therapies.
Collapse
Affiliation(s)
- Rowan K Hussein
- Laboratory of Developmental Neurobiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, MD, United States
| | - Caitlin P Mencio
- Laboratory of Developmental Neurobiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, MD, United States
| | - Yasuhiro Katagiri
- Laboratory of Developmental Neurobiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, MD, United States
| | - Alexis M Brake
- Laboratory of Developmental Neurobiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, MD, United States
| | - Herbert M Geller
- Laboratory of Developmental Neurobiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
5
|
Prager J, Adams CF, Delaney AM, Chanoit G, Tarlton JF, Wong LF, Chari DM, Granger N. Stiffness-matched biomaterial implants for cell delivery: clinical, intraoperative ultrasound elastography provides a 'target' stiffness for hydrogel synthesis in spinal cord injury. J Tissue Eng 2020; 11:2041731420934806. [PMID: 32670538 PMCID: PMC7336822 DOI: 10.1177/2041731420934806] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 05/21/2020] [Indexed: 12/14/2022] Open
Abstract
Safe hydrogel delivery requires stiffness-matching with host tissues to avoid
iatrogenic damage and reduce inflammatory reactions. Hydrogel-encapsulated cell
delivery is a promising combinatorial approach to spinal cord injury therapy,
but a lack of in vivo clinical spinal cord injury stiffness
measurements is a barrier to their use in clinics. We demonstrate that
ultrasound elastography – a non-invasive, clinically established tool – can be
used to measure spinal cord stiffness intraoperatively in canines with
spontaneous spinal cord injury. In line with recent experimental reports, our
data show that injured spinal cord has lower stiffness than uninjured cord. We
show that the stiffness of hydrogels encapsulating a clinically relevant
transplant population (olfactory ensheathing cells) can also be measured by
ultrasound elastography, enabling synthesis of hydrogels with comparable
stiffness to canine spinal cord injury. We therefore demonstrate
proof-of-principle of a novel approach to stiffness-matching hydrogel-olfactory
ensheathing cell implants to ‘real-life’ spinal cord injury values; an approach
applicable to multiple biomaterial implants for regenerative therapies.
Collapse
Affiliation(s)
- Jon Prager
- Bristol Veterinary School, University of Bristol, Bristol, UK.,The Royal Veterinary College, University of London, Hatfield, UK
| | - Christopher F Adams
- Cellular and Neural Engineering Group, Institute for Science and Technology in Medicine, Keele University, Keele, UK
| | - Alexander M Delaney
- Cellular and Neural Engineering Group, Institute for Science and Technology in Medicine, Keele University, Keele, UK
| | | | - John F Tarlton
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | | | - Divya M Chari
- Cellular and Neural Engineering Group, Institute for Science and Technology in Medicine, Keele University, Keele, UK
| | - Nicolas Granger
- The Royal Veterinary College, University of London, Hatfield, UK
| |
Collapse
|
6
|
Romereim SM, Johnston CA, Redwine AL, Wachs RA. Development of an in vitro intervertebral disc innervation model to screen neuroinhibitory biomaterials. J Orthop Res 2020; 38:1016-1026. [PMID: 31825104 PMCID: PMC7244214 DOI: 10.1002/jor.24557] [Citation(s) in RCA: 4] [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: 08/14/2019] [Accepted: 11/30/2019] [Indexed: 02/04/2023]
Abstract
Pain originating from an intervertebral disc (discogenic pain) is a major source of chronic low back pain. Pathological innervation of the disc by pain-sensing nerve fibers is thought to be a key component of discogenic pain, so treatment with biomaterials that have the ability to inhibit neurite growth will greatly benefit novel disc therapeutics. Currently, disc therapeutic biomaterials are rarely screened for their ability to modulate nerve growth, mainly due to a lack of models to screen neuromodulation. To address this deficit, our lab has engineered a three dimensional in vitro disc innervation model that mimics the interface between primary sensory nerves and the intervertebral disc. Further, herein we have demonstrated the utility of this model to screen the efficacy of chondroitin sulfate biomaterials to inhibit nerve fiber invasion into the model disc. Biomaterials containing chondroitin-4-sulfate (CS-A) decrease neurite growth in a uniform gel and at an interface between a growth-permissive and a growth-inhibitory gel, while chondroitin-6-sulfate (CS-C) is less neuroinhibitory. This in vitro model holds great potential for screening inhibitors of nerve fiber growth to further improve intervertebral disc replacements and therapeutics. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1016-1026, 2020.
Collapse
Affiliation(s)
- Sarah M Romereim
- Biological Systems Engineering, University of Nebraska-Lincoln, P.O. Box 830726, Lincoln, Nebraska, 68583-0726
| | - Caleb A Johnston
- Biological Systems Engineering, University of Nebraska-Lincoln, P.O. Box 830726, Lincoln, Nebraska, 68583-0726
| | - Adan L Redwine
- Biological Systems Engineering, University of Nebraska-Lincoln, P.O. Box 830726, Lincoln, Nebraska, 68583-0726
| | - Rebecca A Wachs
- Biological Systems Engineering, University of Nebraska-Lincoln, P.O. Box 830726, Lincoln, Nebraska, 68583-0726
| |
Collapse
|
7
|
Spearman BS, Agrawal NK, Rubiano A, Simmons CS, Mobini S, Schmidt CE. Tunable methacrylated hyaluronic acid-based hydrogels as scaffolds for soft tissue engineering applications. J Biomed Mater Res A 2020; 108:279-291. [PMID: 31606936 PMCID: PMC8591545 DOI: 10.1002/jbm.a.36814] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 09/26/2019] [Accepted: 10/01/2019] [Indexed: 01/18/2023]
Abstract
Hyaluronic acid (HA)-based biomaterials have been explored for a number of applications in biomedical engineering, particularly as tissue regeneration scaffolds. Crosslinked forms of HA are more robust and provide tunable mechanical properties and degradation rates that are critical in regenerative medicine; however, crosslinking modalities reported in the literature vary and there are few comparisons of different scaffold properties for various crosslinking approaches. In this study, we offer direct comparison of two methacrylation techniques for HA (glycidyl methacrylate HA [GMHA] or methacrylic anhydride HA [MAHA]). The two methods for methacrylating HA provide degrees of methacrylation ranging from 2.4 to 86%, reflecting a wider range of properties than is possible using only a single methacrylation technique. We have also characterized mechanical properties for nine different tissues isolated from rat (ranging from lung at the softest to muscle at the stiffest) using indentation techniques and show that we can match the full range of mechanical properties (0.35-6.13 kPa) using either GMHA or MAHA. To illustrate utility for neural tissue engineering applications, functional hydrogels with adhesive proteins (either GMHA or MAHA base hydrogels with collagen I and laminin) were designed with effective moduli mechanically matched to rat sciatic nerve (2.47 ± 0.31 kPa). We demonstrated ability of these hydrogels to support three-dimensional axonal elongation from dorsal root ganglia cultures. Overall, we have shown that methacrylated HA provides a tunable platform with a wide range of properties for use in soft tissue engineering.
Collapse
Affiliation(s)
- Benjamin S. Spearman
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | - Nikunj K. Agrawal
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
| | - Andrés Rubiano
- Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL
| | - Chelsey S. Simmons
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
- Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL
| | - Sahba Mobini
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
- Instituto de Micro y Nanotecnología, IMN-CNM, CSIC (CEI UAM+CSIC), Madrid, Spain
- Departamento de Biología Molecular and Centro de Biología Molecular, Universidad Autónoma de Madrid, Madrid, Spain
| | - Christine E. Schmidt
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL
| |
Collapse
|
8
|
Cooper JG, Sicard D, Sharma S, Van Gulden S, McGuire TL, Cajiao MP, Tschumperlin DJ, Kessler JA. Spinal Cord Injury Results in Chronic Mechanical Stiffening. J Neurotrauma 2020; 37:494-506. [PMID: 31516087 PMCID: PMC6978780 DOI: 10.1089/neu.2019.6540] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Gliosis and fibrosis after spinal cord injury (SCI) lead to formation of a scar that is thought to present both molecular and mechanical barriers to neuronal regeneration. The scar consists of a meshwork of reactive glia and deposited, cross-linked, extracellular matrix (ECM) that has long been assumed to present a mechanically "stiff" blockade. However, remarkably little quantitative information is available about the rheological properties of chronically injured spinal tissue. In this study we utilize atomic force microscopy microindentation to provide quantitative evidence of chronic mechanical stiffening after SCI. Using the results of this tissue characterization, we assessed the sensitivity of both mouse and human astrocytes in vitro and determined that they are exquisitely mechanosensitive within the relevant range of substrate stiffness observed in the injured/uninjured spinal cord. We then utilized a novel immune modifying nanoparticle (IMP) treatment as a tool to reveal fibrotic scarring as one of the key drivers of mechanical stiffening after SCI in vivo. We also demonstrate that glial scar-forming astrocytes form a highly aligned, anisotropic network of glial fibers after SCI, and that IMP treatment mitigates this pathological alignment. Taken together, our results identify chronic mechanical stiffening as a critically important aspect of the complex lesion milieu after SCI that must be considered when assessing and developing potential clinical interventions for SCI.
Collapse
Affiliation(s)
- John G. Cooper
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Delphine Sicard
- Department of Physiology and Biomedical Engineering, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota
| | - Sripadh Sharma
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Stephanie Van Gulden
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Tammy L. McGuire
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Miguel Pareja Cajiao
- Department of Anesthesiology, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota
| | - Daniel J. Tschumperlin
- Department of Physiology and Biomedical Engineering, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota
| | - John A. Kessler
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
9
|
Frost GR, Jonas LA, Li YM. Friend, Foe or Both? Immune Activity in Alzheimer's Disease. Front Aging Neurosci 2019; 11:337. [PMID: 31920620 PMCID: PMC6916654 DOI: 10.3389/fnagi.2019.00337] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 11/21/2019] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is marked by the presence of amyloid beta (Aβ) plaques, neurofibrillary tangles (NFT), neuronal death and synaptic loss, and inflammation in the brain. AD research has, in large part, been dedicated to the understanding of Aβ and NFT deposition as well as to the pharmacological reduction of these hallmarks. However, recent GWAS data indicates neuroinflammation plays a critical role in AD development, thereby redirecting research efforts toward unveiling the complexities of AD-associated neuroinflammation. It is clear that the innate immune system is intimately associated with AD progression, however, the specific roles of glia and neuroinflammation in AD pathology remain to be described. Moreover, inflammatory processes have largely been painted as detrimental to AD pathology, when in fact, many immune mechanisms such as phagocytosis aid in the reduction of AD pathologies. In this review, we aim to outline the delicate balance between the beneficial and detrimental aspects of immune activation in AD as a more thorough understanding of these processes is critical to development of effective therapeutics for AD.
Collapse
Affiliation(s)
- Georgia R. Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
| | - Lauren A. Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
| |
Collapse
|
10
|
Picoli CC, Coimbra-Campos LMC, Guerra DAP, Silva WN, Prazeres PHDM, Costa AC, Magno LAV, Romano-Silva MA, Mintz A, Birbrair A. Pericytes Act as Key Players in Spinal Cord Injury. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:1327-1337. [PMID: 31014955 DOI: 10.1016/j.ajpath.2019.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 03/08/2019] [Accepted: 03/28/2019] [Indexed: 02/06/2023]
Abstract
Spinal cord injury results in locomotor impairment attributable to the formation of an inhibitory fibrous scar, which prevents axonal regeneration after trauma. The scarcity of knowledge about the molecular and cellular mechanisms involved in scar formation after spinal cord lesion impede the design of effective therapies. Recent studies, by using state-of-the-art technologies, including genetic tracking and blockage of pericytes in combination with optogenetics, reveal that pericyte blockage facilitates axonal regeneration and neuronal integration into the local neural circuitry. Strikingly, a pericyte subset is essential during scarring after spinal cord injury, and its arrest results in motor performance improvement. The arising knowledge from current research will contribute to novel approaches to develop therapies for spinal cord injury. We review novel advances in our understanding of pericyte biology in the spinal cord.
Collapse
Affiliation(s)
- Caroline C Picoli
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Daniel A P Guerra
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Walison N Silva
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Pedro H D M Prazeres
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Alinne C Costa
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Luiz A V Magno
- Department of Mental Health, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Marco A Romano-Silva
- Department of Mental Health, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Akiva Mintz
- Department of Radiology, Columbia University Medical Center, New York, New York
| | - Alexander Birbrair
- Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, Brazil; Department of Radiology, Columbia University Medical Center, New York, New York.
| |
Collapse
|
11
|
Mobini S, Song YH, McCrary MW, Schmidt CE. Advances in ex vivo models and lab-on-a-chip devices for neural tissue engineering. Biomaterials 2019; 198:146-166. [PMID: 29880219 PMCID: PMC6957334 DOI: 10.1016/j.biomaterials.2018.05.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/25/2018] [Accepted: 05/07/2018] [Indexed: 02/08/2023]
Abstract
The technologies related to ex vivo models and lab-on-a-chip devices for studying the regeneration of brain, spinal cord, and peripheral nerve tissues are essential tools for neural tissue engineering and regenerative medicine research. The need for ex vivo systems, lab-on-a-chip technologies and disease models for neural tissue engineering applications are emerging to overcome the shortages and drawbacks of traditional in vitro systems and animal models. Ex vivo models have evolved from traditional 2D cell culture models to 3D tissue-engineered scaffold systems, bioreactors, and recently organoid test beds. In addition to ex vivo model systems, we discuss lab-on-a-chip devices and technologies specifically for neural tissue engineering applications. Finally, we review current commercial products that mimic diseased and normal neural tissues, and discuss the future directions in this field.
Collapse
Affiliation(s)
- Sahba Mobini
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Young Hye Song
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Michaela W McCrary
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Christine E Schmidt
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
| |
Collapse
|
12
|
Rayner MLD, Laranjeira S, Evans RE, Shipley RJ, Healy J, Phillips JB. Developing an In Vitro Model to Screen Drugs for Nerve Regeneration. Anat Rec (Hoboken) 2018; 301:1628-1637. [PMID: 30334365 PMCID: PMC6282521 DOI: 10.1002/ar.23918] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/24/2018] [Accepted: 03/25/2018] [Indexed: 12/29/2022]
Abstract
Peripheral nerve injuries (PNI) have a high prevalence and can be debilitating, resulting in life‐long loss or disturbance in end‐organ function, which compromises quality of life for patients. Current therapies use microsurgical approaches but there is the potential for enhancing recovery through other therapeutic modalities such as; cell‐based conduits, gene therapy and small molecules. A number of molecular targets and drugs which have the potential to improve nerve regeneration have been identified, however, there are challenges associated with moving therapies toward clinical translation. Due to the lack of detailed knowledge about the pro‐regenerative effect of potential drug treatments, there is a need for effective in vitro models to screen compounds to inform future pre‐clinical and clinical studies. The interaction between regenerating neurites and supporting Schwann cells is a key feature of the nerve environment, therefore, in vitro models that mimic this cellular association are useful tools. In this study, we have investigated various cell culture models, including simple monolayer systems and more complex 3D‐engineered co‐cultures, as models for use in PNI drug development. Anat Rec, 301:1628–1637, 2018. © 2018 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.
Collapse
Affiliation(s)
- Melissa L D Rayner
- Biomaterials & Tissue Engineering, UCL Eastman Dental Institute, WC1X 8LD, London, UK.,Department of Pharmacology, UCL School of Pharmacy, 29-39 Brunswick Square WC1N 1AX, London, UK.,UCL Centre for Nerve Engineering, University College London, WC1E 6BT, London, UK
| | - Simão Laranjeira
- UCL Centre for Nerve Engineering, University College London, WC1E 6BT, London, UK.,UCL Department of Mechanical Engineering, University College London, WC1E 7JEK, London, UK
| | - Rachael E Evans
- Biomaterials & Tissue Engineering, UCL Eastman Dental Institute, WC1X 8LD, London, UK.,Department of Pharmacology, UCL School of Pharmacy, 29-39 Brunswick Square WC1N 1AX, London, UK.,UCL Centre for Nerve Engineering, University College London, WC1E 6BT, London, UK
| | - Rebecca J Shipley
- UCL Centre for Nerve Engineering, University College London, WC1E 6BT, London, UK.,UCL Department of Mechanical Engineering, University College London, WC1E 7JEK, London, UK
| | - Jess Healy
- Department of Pharmacology, UCL School of Pharmacy, 29-39 Brunswick Square WC1N 1AX, London, UK.,UCL Centre for Nerve Engineering, University College London, WC1E 6BT, London, UK
| | - James B Phillips
- Biomaterials & Tissue Engineering, UCL Eastman Dental Institute, WC1X 8LD, London, UK.,Department of Pharmacology, UCL School of Pharmacy, 29-39 Brunswick Square WC1N 1AX, London, UK.,UCL Centre for Nerve Engineering, University College London, WC1E 6BT, London, UK
| |
Collapse
|
13
|
Moeendarbary E, Weber IP, Sheridan GK, Koser DE, Soleman S, Haenzi B, Bradbury EJ, Fawcett J, Franze K. The soft mechanical signature of glial scars in the central nervous system. Nat Commun 2017; 8:14787. [PMID: 28317912 PMCID: PMC5364386 DOI: 10.1038/ncomms14787] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 01/31/2017] [Indexed: 02/02/2023] Open
Abstract
Injury to the central nervous system (CNS) alters the molecular and cellular composition of neural tissue and leads to glial scarring, which inhibits the regrowth of damaged axons. Mammalian glial scars supposedly form a chemical and mechanical barrier to neuronal regeneration. While tremendous effort has been devoted to identifying molecular characteristics of the scar, very little is known about its mechanical properties. Here we characterize spatiotemporal changes of the elastic stiffness of the injured rat neocortex and spinal cord at 1.5 and three weeks post-injury using atomic force microscopy. In contrast to scars in other mammalian tissues, CNS tissue significantly softens after injury. Expression levels of glial intermediate filaments (GFAP, vimentin) and extracellular matrix components (laminin, collagen IV) correlate with tissue softening. As tissue stiffness is a regulator of neuronal growth, our results may help to understand why mammalian neurons do not regenerate after injury.
Collapse
Affiliation(s)
- Emad Moeendarbary
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK,Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave 56, Cambridge, Massachusetts 02139, USA,Department of Mechanical Engineering, University College London, London WC1E 7JE, UK,
| | - Isabell P. Weber
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Graham K. Sheridan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK,School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ, UK
| | - David E. Koser
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Sara Soleman
- John van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
| | - Barbara Haenzi
- John van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
| | - Elizabeth J. Bradbury
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London SE1 1UL, UK
| | - James Fawcett
- John van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
| | - Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK,
| |
Collapse
|
14
|
Shendi D, Dede A, Yin Y, Wang C, Valmikinathan C, Jain A. Tunable, bioactive protein conjugated hyaluronic acid hydrogel for neural engineering applications. J Mater Chem B 2016; 4:2803-2818. [DOI: 10.1039/c5tb02235e] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A one-step Michael addition click chemistry reaction is used to fabricate a bioactive conjugated hyaluronic acid (HA) scaffold for neural engineering applications.
Collapse
Affiliation(s)
- Dalia Shendi
- nano-Neural Therapeutics Laboratory
- Department Biomedical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
| | - Ana Dede
- nano-Neural Therapeutics Laboratory
- Department Biomedical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
| | - Yuan Yin
- nano-Neural Therapeutics Laboratory
- Department Biomedical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
| | - Chaoming Wang
- nano-Neural Therapeutics Laboratory
- Department Biomedical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
| | | | - Anjana Jain
- nano-Neural Therapeutics Laboratory
- Department Biomedical Engineering
- Worcester Polytechnic Institute
- Worcester
- USA
| |
Collapse
|
15
|
Jones TD, Naimipour H, Sun S, Cho M, Alapati SB. Mechanical changes in human dental pulp stem cells during early odontogenic differentiation. J Endod 2014; 41:50-5. [PMID: 25241024 DOI: 10.1016/j.joen.2014.07.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 07/18/2014] [Accepted: 07/28/2014] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Cell adhesion and migration in bioactive scaffolds require actin cytoskeleton remodeling and focal adhesion formation. Additionally, human dental pulp stem cells (hDPSCs) undergo several changes in their mechanical properties during odontogenic differentiation. The effect of factors essential for odontogenesis on actin stress fiber elasticity and focal adhesion formation is not known. METHODS Live hDPSCs cultured in odontogenic media were imaged for cytoskeleton changes using an atomic force microscope. The Young's modulus (kPa) of the cytoskeleton was recorded as a function of culture medium for 10 days. Focal adhesion formation was assessed using immunofluorescence. Cultured hDPSCs were incubated with a monoclonal vinculin antibody, and filamentous actins were visualized using 0.5 μmol/L phalloidin. RESULTS Cytoskeletal elasticity significantly increased in response to odontogenic media. Both the number and physical size of focal adhesions in hDPSCs also increased. Up-regulation of vinculin expression was evident. The increase in the formation of focal adhesions was consistent with actin remodeling to stress fibers. CONCLUSIONS Our findings suggest that hDPSCs firmly attach to the glass substrate in response to odontogenic media. Successful regeneration of pulp-dentin tissue using biomimetic scaffolds will likely require cell-extracellular matrix interactions influenced by biochemical induction factors.
Collapse
Affiliation(s)
- Taneka D Jones
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Hamed Naimipour
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Shan Sun
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Michael Cho
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - Satish B Alapati
- Department of Endodontics, University of Illinois at Chicago, Chicago, Illinois.
| |
Collapse
|
16
|
Butterfield KC, Conovaloff AW, Panitch A. Development of affinity-based delivery of NGF from a chondroitin sulfate biomaterial. BIOMATTER 2014; 1:174-81. [PMID: 23507746 PMCID: PMC3549888 DOI: 10.4161/biom.18791] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chondroitin sulfate is a major component of the extracellular matrix in both the central and peripheral nervous systems. Chondroitin sulfate is upregulated at injury, thus methods to promote neurite extension through chondroitin sulfate-rich matrices and synthetic scaffolds are needed. We describe the use of both chondroitin sulfate and a novel chondroitin sulfate-binding peptide to control the release of nerve growth factor. Interestingly, the novel chondroitin sulfate-binding peptide enhances the controlled release properties of the chondroitin sulfate gels. While introduction of chondroitin sulfate into a scaffold inhibits primary cortical outgrowth, the combination of chondroitin sulfate, chondroitin sulfate-binding peptide and nerve growth factor promotes primary cortical neurite outgrowth in chondroitin sulfate gels.
Collapse
|
17
|
Redirection of Neurite Outgrowth by Coupling Chondroitin Sulfate Proteoglycans to Polymer Membranes. Ann Biomed Eng 2014; 42:1271-81. [DOI: 10.1007/s10439-014-0991-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 02/19/2014] [Indexed: 12/14/2022]
|
18
|
Colello RJ, Chow WN, Bigbee JW, Lin C, Dalton D, Brown D, Jha BS, Mathern BE, Lee KD, Simpson DG. The incorporation of growth factor and chondroitinase ABC into an electrospun scaffold to promote axon regrowth following spinal cord injury. J Tissue Eng Regen Med 2013; 10:656-68. [DOI: 10.1002/term.1805] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/27/2013] [Accepted: 07/15/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Raymond J. Colello
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Woon N. Chow
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - John W. Bigbee
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Charles Lin
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Dustin Dalton
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Damien Brown
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Balendu Shekhar Jha
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Bruce E. Mathern
- Department of Neurosurgery, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - Kangmin D. Lee
- Department of Neurosurgery, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| | - David G. Simpson
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus; Virginia Commonwealth University; Richmond VA USA
| |
Collapse
|
19
|
Peng J, Pan Q, Zhang W, Yang H, Zhou X, Jiang H. Effects of DS-modified agarose gels on neurite extension in 3D scaffold through mechanisms other than changing the pore radius of the gels. J Biomed Mater Res A 2013; 102:2157-62. [PMID: 23894002 DOI: 10.1002/jbm.a.34892] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/26/2013] [Accepted: 07/22/2013] [Indexed: 01/30/2023]
Abstract
Dermatan sulfate is widely distributed as glycosaminoglycan side chains of proteoglycans, which are the main components of glial scar and inhibit neurite regeneration after nerve injury. However its role in the inhibiting process is not clear. Understanding neurite extension in three-dimensional scaffolds is critical for neural tissue engineering. This study used agarose gels modified with dermatan sulfate as the three-dimensional culture scaffold. We explored structure-function relationship between the three-dimensional scaffold and neurite extension and examined the role of dermatan sulfate on neurite extension in the three-dimensional scaffold. A range of agarose concentrations was used to generate varied gel physical structures and the corresponding neurite extension of embryonic day (E9) chick dorsal root ganglia was examined. We measured gel stiffness and gel pore size to determine whether dermatan sulfate changed the gels' conformation. As gel concentration increased, neurite length and gel pore size decreased, and gel stiffness increased. At 1.00 and 1.25% (wt/vol) concentrations, dermatan sulfates both immobilized with agarose gels and dissolved in culture medium inhibit neurite extension. While at 1.50 and 1.75% (wt/vol) concentrations, only immobilized dermatan sulfate worked. Immobilized dermatan sulfate could modify molecular shape of agarose gels, decrease gel pore size statistically, but did not influence gel stiffness. We have proved that the decrease of gel pore size is insufficient to inhibit neurite extension. These results indicate that dermatan sulfate inhibits neurite extension not through forming a mechanical barrier. Maybe its interaction with neuron membrane is the key factor in neurite extension.
Collapse
Affiliation(s)
- Jin Peng
- West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan Province, People's Republic of China; Metabonomics and Multidisciplinary Laboratory for Trauma Research, Sichuan Provincial People's Hospital, Sichuan Academy of Medical Sciences, Chengdu, Sichuan Province, People's Republic of China
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
Biological cells are well known to respond to a multitude of chemical signals. In the nervous system, chemical signaling has been shown to be crucially involved in development, normal functioning, and disorders of neurons and glial cells. However, there are an increasing number of studies showing that these cells also respond to mechanical cues. Here, we summarize current knowledge about the mechanical properties of nervous tissue and its building blocks, review recent progress in methodology and understanding of cellular mechanosensitivity in the nervous system, and provide an outlook on the implications of neuromechanics for future developments in biomedical engineering to aid overcoming some of the most devastating and currently incurable CNS pathologies such as spinal cord injuries and multiple sclerosis.
Collapse
Affiliation(s)
- Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK.
| | | | | |
Collapse
|
21
|
Francis NL, Hunger PM, Donius AE, Riblett BW, Zavaliangos A, Wegst UGK, Wheatley MA. An ice-templated, linearly aligned chitosan-alginate scaffold for neural tissue engineering. J Biomed Mater Res A 2013; 101:3493-503. [PMID: 23596011 DOI: 10.1002/jbm.a.34668] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 02/12/2013] [Accepted: 02/13/2013] [Indexed: 11/06/2022]
Abstract
Several strategies have been investigated to enhance axonal regeneration after spinal cord injury, however, the resulting growth can be random and disorganized. Bioengineered scaffolds provide a physical substrate for guidance of regenerating axons towards their targets, and can be produced by freeze casting. This technique involves the controlled directional solidification of an aqueous solution or suspension, resulting in a linearly aligned porous structure caused by ice templating. In this study, freeze casting was used to fabricate porous chitosan-alginate (C/A) scaffolds with longitudinally oriented channels. Chick dorsal root ganglia explants adhered to and extended neurites through the scaffold in parallel alignment with the channel direction. Surface adsorption of a polycation and laminin promoted significantly longer neurite growth than the uncoated scaffold (poly-L-ornithine + Laminin = 793.2 ± 187.2 μm; poly-L-lysine + Laminin = 768.7 ± 241.2 μm; uncoated scaffold = 22.52 ± 50.14 μm) (P < 0.001). The elastic modulus of the hydrated scaffold was determined to be 5.08 ± 0.61 kPa, comparable to reported spinal cord values. The present data suggested that this C/A scaffold is a promising candidate for use as a nerve guidance scaffold, because of its ability to support neuronal attachment and the linearly aligned growth of DRG neurites.
Collapse
Affiliation(s)
- Nicola L Francis
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, 3141 Chestnut Street, Philadelphia
| | | | | | | | | | | | | |
Collapse
|
22
|
Beller JA, Kulengowski B, Kobraei EM, Curinga G, Calulot CM, Bahrami A, Hering TM, Snow DM. Comparison of sensory neuron growth cone and filopodial responses to structurally diverse aggrecan variants, in vitro. Exp Neurol 2013; 247:143-57. [PMID: 23458191 DOI: 10.1016/j.expneurol.2013.02.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/06/2013] [Accepted: 02/18/2013] [Indexed: 12/20/2022]
Abstract
Following spinal cord injury, a regenerating neurite encounters a glial scar enriched in chondroitin sulfate proteoglycans (CSPGs), which presents a major barrier. There are two points at which a neurite makes contact with glial scar CSPGs: initially, filopodia surrounding the growth cone extend and make contact with CSPGs, then the peripheral domain of the entire growth cone makes CSPG contact. Aggrecan is a CSPG commonly used to model the effect CSPGs have on elongating or regenerating neurites. In this study, we investigated filopodia and growth cone responses to contact with structurally diverse aggrecan variants using the common stripe assay. Using time-lapse imaging with 15-s intervals, we measured growth cone area, growth cone width, growth cone length, filopodia number, total filopodia length, and the length of the longest filopodia following contact with aggrecan. Responses were measured after both filopodia and growth cone contact with five different preparations of aggrecan: two forms of aggrecan derived from bovine articular cartilage (purified and prepared using different techniques), recombinant aggrecan lacking chondroitin sulfate side chains (produced in CHO-745 cells) and two additional recombinant aggrecan preparations with varying lengths of chondroitin sulfate side chains (produced in CHO-K1 and COS-7 cells). Responses in filopodia and growth cone behavior differed between the structurally diverse aggrecan variants. Mutant CHO-745 aggrecan (lacking chondroitin sulfate chains) permitted extensive growth across the PG stripe. Filopodia contact with the CHO-745 aggrecan caused a significant increase in growth cone width and filopodia length (112.7% ± 4.9 and 150.9% ± 7.2 respectively, p<0.05), and subsequently upon growth cone contact, growth cone width remained elevated along with a reduction in filopodia number (121.9% ± 4.2; 72.39% ± 6.4, p<0.05). COS-7 derived aggrecan inhibited neurite outgrowth following growth cone contact. Filopodia contact produced an increase in growth cone area and width (126.5% ± 8.1; 150.3% ± 13.31, p<0.001), and while these parameters returned to baseline upon growth cone contact, a reduction in filopodia number and length was observed (73.94% ± 5.8, 75.3% ± 6.2, p<0.05). CHO-K1 derived aggrecan inhibited neurite outgrowth following filopodia contact, and caused an increase in growth cone area and length (157.6% ± 6.2; 117.0% ± 2.8, p<0.001). Interestingly, the two bovine articular cartilage aggrecan preparations differed in their effects on neurite outgrowth. The proprietary aggrecan (BA I, Sigma-Aldrich) inhibited neurites at the point of growth cone contact, while our chemically purified aggrecan (BA II) inhibited neurite outgrowth at the point of filopodia contact. BA I caused a reduction in growth cone width following filopodia contact (91.7% ± 2.5, p<0.05). Upon growth cone contact, there was a further reduction in growth cone width and area (66.4% ± 2.2; 75.6% ± 2.9; p<0.05), as well as reductions in filopodia number, total length, and max length (75.9% ± 5.7, p<0.05; 68.8% ± 6.0; 69.6% ± 3.5, p<0.001). Upon filopodia contact, BA II caused a significant increase in growth cone area, and reductions in filopodia number and total filopodia length (115.9% ± 5.4, p<0.05; 72.5% ± 2.7; 77.7% ± 3.2, p<0.001). In addition, filopodia contact with BA I caused a significant reduction in growth cone velocity (38.6 nm/s ± 1.3 before contact, 17.1 nm/s ± 3.6 after contact). These data showed that neuron morphology and behavior are differentially dependent upon aggrecan structure. Furthermore, the behavioral changes associated with the approaching growth cone may be predictive of inhibition or growth.
Collapse
Affiliation(s)
- Justin A Beller
- Spinal Cord and Brain Injury Research Center, and Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Goonoo N, Bhaw-Luximon A, Bowlin GL, Jhurry D. An assessment of biopolymer- and synthetic polymer-based scaffolds for bone and vascular tissue engineering. POLYM INT 2013. [DOI: 10.1002/pi.4474] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Nowsheen Goonoo
- ANDI Centre of Excellence for Biomedical and Biomaterials Research, MSIRI Building; University of Mauritius; Réduit Mauritius
| | - Archana Bhaw-Luximon
- ANDI Centre of Excellence for Biomedical and Biomaterials Research, MSIRI Building; University of Mauritius; Réduit Mauritius
| | - Gary L Bowlin
- Department of Biomedical Engineering, Virginia Commonwealth University; Richmond; Virginia USA
| | - Dhanjay Jhurry
- ANDI Centre of Excellence for Biomedical and Biomaterials Research, MSIRI Building; University of Mauritius; Réduit Mauritius
| |
Collapse
|
24
|
Tuinstra HM, Ducommun MM, Briley WE, Shea LD. Gene delivery to overcome astrocyte inhibition of axonal growth: an in vitro model of the glial scar. Biotechnol Bioeng 2012; 110:947-57. [PMID: 23055330 DOI: 10.1002/bit.24750] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/03/2012] [Accepted: 10/05/2012] [Indexed: 01/31/2023]
Abstract
After injury to the central nervous system, a glial scar develops that physically and biochemically inhibits axon growth. In the scar, activated astrocytes secrete inhibitory extracellular matrix, of which chondroitin sulfate proteoglycans (CSPGs) are considered the major inhibitory component. An inhibitory interface of CSPGs forms around the lesion and prevents axons from traversing the injury, and decreasing CSPGs can enhance axon growth. In this report, we established an in vitro interface model of activated astrocytes and subsequently investigated gene delivery as a means to reduce CSPG levels and enhance axon growth. In the model, a continuous interface of CSPG producing astrocytes was created with neurons seeded opposite the astrocytes, and neurite crossing, stopping, and turning were evaluated as they approached the interface. We investigated the efficacy of lentiviral delivery to degrade or prevent the synthesis of CSPGs, thereby removing CSPG inhibition of neurite growth. Lentiviral delivery of RNAi targeting two key CSPG synthesis enzymes, chondroitin polymerizing factor and chondroitin synthase-1, decreased CSPGs, and reduced inhibition by the interface. Degradation of CSPGs by lentiviral delivery of chondroitinase also resulted in less inhibition and more neurites crossing the interface. These results indicate that the interface model provides a tool to investigate interventions that reduce inhibition by CSPGs, and that gene delivery can be effective in promoting neurite growth across an interface of CSPG producing astrocytes.
Collapse
Affiliation(s)
- Hannah M Tuinstra
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | | | | | | |
Collapse
|
25
|
Fuhs T, Reuter L, Vonderhaid I, Claudepierre T, Käs JA. Inherently slow and weak forward forces of neuronal growth cones measured by a drift-stabilized atomic force microscope. Cytoskeleton (Hoboken) 2012; 70:44-53. [DOI: 10.1002/cm.21080] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 09/16/2012] [Indexed: 12/11/2022]
|
26
|
Moore SW, Sheetz MP. Biophysics of substrate interaction: influence on neural motility, differentiation, and repair. Dev Neurobiol 2012; 71:1090-101. [PMID: 21739614 DOI: 10.1002/dneu.20947] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The identity and behavior of a cell is shaped by the molecular and mechanical composition of its surroundings. Molecular cues have firmly established roles in guiding both neuronal fate decisions and the migration of cells and axons. However, there is growing evidence that topographical and rigidity cues in the extracellular environment act synergistically with these molecular cues. Like chemical cues, physical factors do not elicit a fixed response, but rather one that depends on the sensory makeup of the cell. Moreover, from developmental studies and the plasticity of neural tissue, it is evident that there is dynamic feedback between physical and chemical factors to produce the final morphology. Here, we focus on our current understanding of how these physical cues shape cellular differentiation and migration, and discuss their relevance to repairing the injured nervous system.
Collapse
Affiliation(s)
- Simon W Moore
- Department of Biological Sciences, Columbia University, Sherman Fairchild Center, Amsterdam Ave., New York, NY 10027, USA.
| | | |
Collapse
|
27
|
East E, Golding JP, Phillips JB. Engineering an integrated cellular interface in three-dimensional hydrogel cultures permits monitoring of reciprocal astrocyte and neuronal responses. Tissue Eng Part C Methods 2012; 18:526-36. [PMID: 22235832 PMCID: PMC3381295 DOI: 10.1089/ten.tec.2011.0587] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/09/2012] [Indexed: 11/12/2022] Open
Abstract
This study reports a new type of three-dimensional (3D) tissue model for studying interactions between cell types in collagen hydrogels. The aim was to create a 3D cell culture model containing separate cell populations in close proximity without the presence of a mechanical barrier, and demonstrate its relevance to modeling the axon growth-inhibitory cellular interfaces that develop in the central nervous system (CNS) in response to damage. This provides a powerful new tool to determine which aspects of the astroglial scar response and subsequent neuronal regeneration inhibition are determined by the presence of the other cell types. Astrocytes (CNS glia) and dissociated dorsal root ganglia (DRG; containing neurons and peripheral nervous system [PNS] glia) were seeded within collagen solution at 4 °C in adjacent chambers of a stainless steel mould, using cells cultured from wild-type or green fluorescent protein expressing rats, to track specific populations. The divider between the chambers was removed using a protocol that allowed the gels to integrate without mixing of the cell populations. Following setting of the gels, they were maintained in culture for up to 15 days. Reciprocal astrocyte and neuronal responses were monitored using confocal microscopy and 3D image analysis. At DRG:astrocyte interfaces, by 5 days there was an increase in the number of astrocytes at the interface followed by hypertrophy and increased glial fibrillary acidic protein expression at 10 and 15 days, indicative of reactive gliosis. Neurons avoided crossing DRG:astrocyte interfaces, and neuronal growth was restricted to the DRG part of the gel. By contrast, neurons were able to grow freely across DRG:DRG interfaces, demonstrating the absence of a mechanical barrier. These results show that in a precisely controlled 3D environment, an interface between DRG and astrocyte cultures is sufficient to trigger reactive gliosis and inhibition of neuronal regeneration across the interface. Different aspects of the astrocyte response could be independently monitored, providing an insight into the formation of a glial scar. This technology has wide potential for researchers wishing to maintain and monitor interactions between adjacent cell populations in 3D culture.
Collapse
Affiliation(s)
- Emma East
- Faculty of Science, The Open University, Milton Keynes, United Kingdom
| | | | | |
Collapse
|
28
|
Swindle-Reilly KE, Papke JB, Kutosky HP, Throm A, Hammer JA, Harkins AB, Willits RK. The impact of laminin on 3D neurite extension in collagen gels. J Neural Eng 2012; 9:046007. [DOI: 10.1088/1741-2560/9/4/046007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
29
|
Saxena T, Gilbert J, Stelzner D, Hasenwinkel J. Mechanical characterization of the injured spinal cord after lateral spinal hemisection injury in the rat. J Neurotrauma 2012; 29:1747-57. [PMID: 22435754 DOI: 10.1089/neu.2011.1818] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The glial scar formed at the site of traumatic spinal cord injury (SCI) has been classically hypothesized to be a potent physical and biochemical barrier to nerve regeneration. One longstanding hypothesis is that the scar acts as a physical barrier due to its increased stiffness in comparison to uninjured spinal cord tissue. However, the information regarding the mechanical properties of the glial scar in the current literature is mostly anecdotal and not well quantified. We monitored the mechanical relaxation behavior of injured rat spinal cord tissue at the site of mid-thoracic spinal hemisection 2 weeks and 8 weeks post-injury using a microindentation test method. Elastic moduli were calculated and a modified standard linear model (mSLM) was fit to the data to estimate the relaxation time constant and viscosity. The SLM was modified to account for a spectrum of relaxation times, a phenomenon common to biological tissues, by incorporating a stretched exponential term. Injured tissue exhibited significantly lower stiffness and elastic modulus in comparison to uninjured control tissue, and the results from the model parameters indicated that the relaxation time constant and viscosity of injured tissue were significantly higher than controls. This study presents direct micromechanical measurements of injured spinal cord tissue post-injury. The results of this study show that the injured spinal tissue displays complex viscoelastic behavior, likely indicating changes in tissue permeability and diffusivity.
Collapse
Affiliation(s)
- Tarun Saxena
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, USA
| | | | | | | |
Collapse
|
30
|
Wang TY, Forsythe JS, Parish CL, Nisbet DR. Biofunctionalisation of polymeric scaffolds for neural tissue engineering. J Biomater Appl 2012; 27:369-90. [DOI: 10.1177/0885328212443297] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Patients who experience injury to the central or peripheral nervous systems invariably suffer from a range of dysfunctions due to the limited ability for repair and reconstruction of damaged neural tissue. Whilst some treatment strategies can provide symptomatic improvement of motor and cognitive function, they fail to repair the injured circuits and rarely offer long-term disease modification. To this end, the biological molecules, used in combination with neural tissue engineering scaffolds, may provide feasible means to repair damaged neural pathways. This review will focus on three promising classes of neural tissue engineering scaffolds, namely hydrogels, electrospun nanofibres and self-assembling peptides. Additionally, the importance and methods for presenting biologically relevant molecules such as, neurotrophins, extracellular matrix proteins and protein-derived sequences that promote neuronal survival, proliferation and neurite outgrowth into the lesion will be discussed.
Collapse
Affiliation(s)
- TY Wang
- Department of Materials Engineering, Monash University, Victoria, Australia
| | - JS Forsythe
- Department of Materials Engineering, Monash University, Victoria, Australia
| | - CL Parish
- Florey Neuroscience Institute and Centre for Neuroscience, The University of Melbourne, Victoria, Australia
| | - DR Nisbet
- Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australia
| |
Collapse
|
31
|
The roles of neuronal and glial precursors in overcoming chondroitin sulfate proteoglycan inhibition. Exp Neurol 2012; 235:627-37. [PMID: 22498104 DOI: 10.1016/j.expneurol.2012.03.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 03/26/2012] [Indexed: 11/23/2022]
Abstract
The extension of axons through the major inhibitory component of the glial scar, chondroitin sulfate proteoglycans (CSPGs), remains a key obstacle for regeneration following spinal cord injury (SCI). We have previously shown that transplants composed of neuronal and glial restricted precursors (NRP and GRP respectively) promote regeneration and connectivity in the injured spinal cord (Bonner et al., 2010, 2011), however, little is known about the properties of these precursors at a cellular level. We now report that NRP-derived neurons, in contrast to dorsal root ganglion (DRG) neurons, have the ability to extend axons and cross over from a permissive substratum (laminin) onto inhibitory CSPG in vitro. Growth cones of neurons derived from NRP, compared to DRG, exhibit significantly lower levels of the CSPG receptors protein tyrosine phosphatase sigma (PTPσ) and leukocyte common antigen-related phosphatase (LAR). GRP-conditioned medium prepared from the same cell densities did not affect the response of primary sensory neurons to CSPG confirming that the ability of NRP-derived neurons to cross onto CSPG is determined intrinsically. However, GRP-conditioned medium collected from high density cultures increased the probability of DRG axons to cross from LN onto CSPG and increased the length of DRG axons extending on CSPG. Collectively, these results suggest that (1) neurons derived from NRPs are intrinsically insensitive to CSPGs due to low levels of receptor expression, and (2) high levels of factors secreted by GRP can reduce the inhibitory effects of CSPG and promote axonal growth. These observations provide mechanistic insights into the specific roles of NRPs and GRPs in promoting regeneration and repair following SCI.
Collapse
|
32
|
Valmikinathan CM, Mukhatyar VJ, Jain A, Karumbaiah L, Dasari M, Bellamkonda RV. Photocrosslinkable chitosan based hydrogels for neural tissue engineering. SOFT MATTER 2012; 8:1964-1976. [PMID: 29805470 PMCID: PMC5969809 DOI: 10.1039/c1sm06629c] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Hydrogel based scaffolds for neural tissue engineering can provide appropriate physico-chemical and mechanical properties to support neurite extension and facilitate transplantation of cells by acting as 'cell delivery vehicles'. Specifically, in situ gelling systems such as photocrosslinkable hydrogels can potentially conformally fill irregular neural tissue defects and serve as stem cell delivery systems. Here, we report the development of a novel chitosan based photocrosslinkable hydrogel system with tunable mechanical properties and degradation rates. A two-step synthesis of amino-ethyl methacrylate derivitized, degradable, photocrosslinkable chitosan hydrogels is described. When human mesenchymal stem cells were cultured in photocrosslinkable chitosan hydrogels, negligible cytotoxicity was observed. Photocrosslinkable chitosan hydrogels facilitated enhanced neurite differentiation from primary cortical neurons and enhanced neurite extension from dorsal root ganglia (DRG) as compared to agarose based hydrogels with similar storage moduli. Neural stem cells (NSCs) cultured within photocrosslinkable chitosan hydrogels facilitated differentiation into tubulin positive neurons and astrocytes. These data demonstrate the potential of photocrosslinked chitosan hydrogels, and contribute to an increasing repertoire of hydrogels designed for neural tissue engineering.
Collapse
Affiliation(s)
- Chandra M. Valmikinathan
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Vivek J. Mukhatyar
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Anjana Jain
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Lohitash Karumbaiah
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Madhuri Dasari
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Ravi V. Bellamkonda
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
- ; Fax: +1 404 385 5044; Tel: +1 404 385 5038
| |
Collapse
|
33
|
Abstract
Spinal cord injury (SCI) presents a complex regenerative problem due to the multiple facets of growth inhibition that occur following trauma to the cord parenchyma and stroma. Clinically, SCI is further complicated by the heterogeneity in the size, shape and extent of human injuries. Many of these injuries do not breach the dura mater and have continuous viable axons through the injury site that can later lead to some degree of functional recovery. In these cases, surgical manipulation of the spinal cord by implanting a preformed scaffold or drug delivery device may lead to further damage. Given these circumstances, in situ-forming scaffolds are an attractive approach for SCI regeneration. These synthetic and natural polymers undergo a rapid transformation from liquid to gel upon injection into the cord tissue, conforming to the individual lesion site and directly integrating with the host tissue. Injectable materials can be formulated to have mechanical properties that closely match the native spinal cord extracellular matrix, and this may enhance axonal ingrowth. Such materials can also be loaded with cellular and molecular therapeutics to modulate the wound environment and enhance regeneration. This review will focus on the current status of in situ-forming materials for spinal cord repair. The advantages of, and requirements for, such polymers will be presented, and examples of the behavior of such systems in vitro and in vivo will be presented. There are helpful lessons to be learned from the investigations of injectable hydrogels for the treatment of SCI that apply to the use of these biomaterials for the treatment of lesions in other central nervous system tissues and in organs comprising other tissue types.
Collapse
Affiliation(s)
- D Macaya
- Tissue Engineering, VA Boston Healthcare System, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | |
Collapse
|
34
|
McCormick AM, Leipzig ND. Neural regenerative strategies incorporating biomolecular axon guidance signals. Ann Biomed Eng 2012; 40:578-97. [PMID: 22218702 DOI: 10.1007/s10439-011-0505-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 12/28/2011] [Indexed: 01/19/2023]
Abstract
There are currently no acceptable cures for central nervous system injuries, and damage induced large gaps in the peripheral nervous system have been challenging to bridge to restore neural functionality. Innervation by neurons is made possible by the growth cone. This dynamic structure is unique to neurons, and can directly sense physical and chemical activity in its environment, utilizing these cues to propel axons to precisely reach their targets. Guidance can occur through chemoattractive factors such as neurotrophins and netrins, chemorepulsive agents like semaphorins and slits, or contact-mediated molecules such as ephrins and those located in the extracellular matrix. The understanding of biomolecular activity during nervous system development and injury has generated new techniques and tactics for improving and restoring function to the nervous system after injury. This review will focus on the major neuronal guidance molecules and their utility in current tissue engineering and neural regenerative strategies.
Collapse
Affiliation(s)
- Aleesha M McCormick
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325-3906, USA
| | | |
Collapse
|
35
|
Ingavle GC, Dormer NH, Gehrke SH, Detamore MS. Using chondroitin sulfate to improve the viability and biosynthesis of chondrocytes encapsulated in interpenetrating network (IPN) hydrogels of agarose and poly(ethylene glycol) diacrylate. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:157-70. [PMID: 22116661 PMCID: PMC3729881 DOI: 10.1007/s10856-011-4499-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 11/09/2011] [Indexed: 05/21/2023]
Abstract
We recently introduced agarose-poly(ethylene glycol) diacrylate (PEGDA) interpenetrating network (IPN) hydrogels to cartilage tissue engineering that were able to encapsulate viable cells and provide a significant improvement in mechanical performance relative to its two constituent hydrogels. The goal of the current study was to develop a novel synthesis protocol to incorporate methacrylated chondroitin sulfate (MCS) into the IPN design hypothesized to improve cell viability and biosynthesis. The IPN was formed by encapsulating porcine chondrocytes in agarose, soaking the construct in a solution of 1:10 MCS:PEGDA, which was then photopolymerized to form a copolymer network as the second network. The IPN with incorporated CS (CS-IPN) (~0.5 wt%) resulted in a 4- to 5-fold increase in the compressive elastic modulus relative to either the PEGDA or agarose gels. After 6 weeks of in vitro culture, more than 50% of the encapsulated chondrocytes remained viable within the CS-modified IPN, in contrast to 35% viability observed in the unmodified. At week 6, the CS-IPN had significantly higher normalized GAG contents (347 ± 34 μg/μg) than unmodified IPNs (158 ± 27 μg/μg, P < 0.05). Overall, the approach of incorporating biopolymers such as CS from native tissue may provide favorable micro-environment and beneficial signals to cells to enhance their overall performance in IPNs.
Collapse
|
36
|
Khaing ZZ, Milman BD, Vanscoy JE, Seidlits SK, Grill RJ, Schmidt CE. High molecular weight hyaluronic acid limits astrocyte activation and scar formation after spinal cord injury. J Neural Eng 2011; 8:046033. [DOI: 10.1088/1741-2560/8/4/046033] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
37
|
Saxena T, Deng B, Stelzner D, Hasenwinkel J, Chaiken J. Raman spectroscopic investigation of spinal cord injury in a rat model. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:027003. [PMID: 21361706 DOI: 10.1117/1.3549700] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Raman spectroscopy was used to study temporal molecular changes associated with spinal cord injury (SCI) in a rat model. Raman spectra of saline-perfused, injured, and healthy rat spinal cords were obtained and compared. Two injury models, a lateral hemisection and a moderate contusion were investigated. The net fluorescence and the Raman spectra showed clear differences between the injured and healthy spinal cords. Based on extensive histological and biochemical characterization of SCI available in the literature, these differences were hypothesized to be due to cell death, demyelination, and changes in the extracellular matrix composition, such as increased expression of proteoglycans and hyaluronic acid, at the site of injury where the glial scar forms. Further, analysis of difference spectra indicated the presence of carbonyl containing compounds, hypothesized to be products of lipid peroxidation and acid catalyzed hydrolysis of glycosaminoglycan moieties. These results compared well with in vitro experiments conducted on chondroitin sulfate sugars. Since the glial scar is thought to be a potent biochemical barrier to nerve regeneration, this observation suggests the possibility of using near infrared Raman spectroscopy to study injury progression and explore potential treatments ex vivo, and ultimately monitor potential remedial treatments within the spinal cord in vivo.
Collapse
Affiliation(s)
- Tarun Saxena
- Syracuse University, Department of Biomedical and Chemical Engineering, Syracuse, New York 13244, USA
| | | | | | | | | |
Collapse
|
38
|
Morrison B, Cullen DK, LaPlaca M. In Vitro Models for Biomechanical Studies of Neural Tissues. NEURAL TISSUE BIOMECHANICS 2011. [DOI: 10.1007/8415_2011_79] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
39
|
Nisbet DR, Rodda AE, Horne MK, Forsythe JS, Finkelstein DI. Implantation of Functionalized Thermally Gelling Xyloglucan Hydrogel Within the Brain: Associated Neurite Infiltration and Inflammatory Response. Tissue Eng Part A 2010; 16:2833-42. [DOI: 10.1089/ten.tea.2009.0677] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- David R. Nisbet
- Department of Materials Engineering, Monash University, Melbourne, Victoria, Australia
- CRC For Polymers, Notting Hill, Victoria, Australia
- The Mental Health Research Institute of Victoria, Parkville, Victoria, Australia
| | - Andrew E. Rodda
- Department of Materials Engineering, Monash University, Melbourne, Victoria, Australia
- CRC For Polymers, Notting Hill, Victoria, Australia
| | - Malcolm K. Horne
- Florey Neurosciences Institute, University of Melbourne, Parkville, Victoria, Australia
- Centre for Neurosciences, University of Melbourne, Parkville, Victoria, Australia
- St. Vincent's Hospital, Fitzroy, Victoria, Australia
| | - John S. Forsythe
- Department of Materials Engineering, Monash University, Melbourne, Victoria, Australia
- CRC For Polymers, Notting Hill, Victoria, Australia
| | - David I. Finkelstein
- The Mental Health Research Institute of Victoria, Parkville, Victoria, Australia
- Centre for Neurosciences, University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
40
|
Cregg JM, Wiseman SL, Pietrzak-Goetze NM, Smith MR, Jaroch DB, Clupper DC, Gilbert RJ. A rapid, quantitative method for assessing axonal extension on biomaterial platforms. Tissue Eng Part C Methods 2010; 16:167-72. [PMID: 19409034 DOI: 10.1089/ten.tec.2009.0108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Measuring outgrowth of neuronal explants is critical in evaluating the ability of a biomaterial to act as a permissive substrate for neuronal adhesion and growth. Previous methods lack the ability to quantify robust outgrowth, or lack the capacity to quantify growth on opaque substrates because they exploit the transparent nature of culture dishes to segregate neuronal processes from an image background based on color intensity. In this study, we sought to investigate the ability of opaque silica sol-gel materials to facilitate axonal outgrowth; therefore, a method was developed for quantifying outgrowth of neurites from dorsal root ganglion explants on these unique surfaces. Dorsal root ganglia were isolated from stage-nine chick embryos and cultured for 48 h on sol-gel materials presenting agarose and chitosan polysaccharides individually or in combination. Explants were then imaged, and basic image analysis software was used by three independent observers to obtain axonal length and axonal area measurements. Robust axon length and axonal spread measurements for ganglia cultured on agarose-chitosan sol-gel matrices yield an estimate of strong neural compatibility for these substrates over silica matrices presenting no polysaccharides, or silica matrices presenting chitosan or agarose individually. We suggest that this simple protocol for quantifying material biocompatibility offers an analysis strategy that can be used universally to the same end.
Collapse
Affiliation(s)
- Jared M Cregg
- Regeneration and Repair Laboratory, Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Christ AF, Franze K, Gautier H, Moshayedi P, Fawcett J, Franklin RJM, Karadottir RT, Guck J. Mechanical difference between white and gray matter in the rat cerebellum measured by scanning force microscopy. J Biomech 2010; 43:2986-92. [PMID: 20656292 DOI: 10.1016/j.jbiomech.2010.07.002] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 07/02/2010] [Accepted: 07/06/2010] [Indexed: 11/26/2022]
Abstract
The mechanical properties of tissues are increasingly recognized as important cues for cell physiology and pathology. Nevertheless, there is a sparsity of quantitative, high-resolution data on mechanical properties of specific tissues. This is especially true for the central nervous system (CNS), which poses particular difficulties in terms of preparation and measurement. We have prepared thin slices of brain tissue suited for indentation measurements on the micrometer scale in a near-native state. Using a scanning force microscope with a spherical indenter of radius ∼20μm we have mapped the effective elastic modulus of rat cerebellum with a spatial resolution of 100μm. We found significant differences between white and gray matter, having effective elastic moduli of K=294±74 and 454±53Pa, respectively, at 3μm indentation depth (n(g)=245, n(w)=150 in four animals, p<0.05; errors are SD). In contrast to many other measurements on larger length scales, our results were constant for indentation depths of 2-4μm indicating a regime of linear effective elastic modulus. These data, assessed with a direct mechanical measurement, provide reliable high-resolution information and serve as a quantitative basis for further neuromechanical investigations on the mechanical properties of developing, adult and damaged CNS tissue.
Collapse
Affiliation(s)
- Andreas F Christ
- Cavendish Laboratory, Department of Physics, University of Cambridge, 19 J.J. Thomson Avenue, Cambridge CB3 0HE, UK
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Luo Y, Kobler JB, Heaton JT, Jia X, Zeitels SM, Langer R. Injectable hyaluronic acid-dextran hydrogels and effects of implantation in ferret vocal fold. J Biomed Mater Res B Appl Biomater 2010; 93:386-93. [PMID: 20151459 DOI: 10.1002/jbm.b.31593] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Injectable hydrogels may potentially be used for augmentation/regeneration of the lamina propria of vocal fold tissue. In this study, hyaluronic acid (HA) and dextran were chemically modified and subsequently crosslinked via formation of hydrazone bonds in phosphate buffer. Swelling ratios, degradation, and compressive moduli of the resulting hydrogels were investigated. It was found that the properties of HA-dextran hydrogels were variable and the trend of variation could be correlated with the hydrogel composition. The biocompatibility of three injectable HA-dextran hydrogels with different crosslinking density was assessed in the vocal fold region using a ferret model. It was found that HA-dextran hydrogels implanted for three weeks stimulated mild foreign-body reactions. Distinct tissue-material interactions were also observed for hydrogels made from different formulations: the hydrogel with the lowest crosslinking density was completely degraded in vivo; while material residues were visible for other types of hydrogel injections, with or without cell penetration into the implantation depending on the hydrogel composition. The in vivo results suggest that the HA-dextran hydrogel matrices can be further developed for applications of vocal fold tissue restoration.
Collapse
Affiliation(s)
- Ying Luo
- Department of Biomedical Engineering, College of Engineering, Peking University, Haidian District, Beijing, China.
| | | | | | | | | | | |
Collapse
|
43
|
Straley KS, Foo CWP, Heilshorn SC. Biomaterial design strategies for the treatment of spinal cord injuries. J Neurotrauma 2010; 27:1-19. [PMID: 19698073 DOI: 10.1089/neu.2009.0948] [Citation(s) in RCA: 225] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The highly debilitating nature of spinal cord injuries has provided much inspiration for the design of novel biomaterials that can stimulate cellular regeneration and functional recovery. Many experts agree that the greatest hope for treatment of spinal cord injuries will involve a combinatorial approach that integrates biomaterial scaffolds, cell transplantation, and molecule delivery. This manuscript presents a comprehensive review of biomaterial-scaffold design strategies currently being applied to the development of nerve guidance channels and hydrogels that more effectively stimulate spinal cord tissue regeneration. To enhance the regenerative capacity of these two scaffold types, researchers are focusing on optimizing the mechanical properties, cell-adhesivity, biodegradability, electrical activity, and topography of synthetic and natural materials, and are developing mechanisms to use these scaffolds to deliver cells and biomolecules. Developing scaffolds that address several of these key design parameters will lead to more successful therapies for the regeneration of spinal cord tissue.
Collapse
Affiliation(s)
- Karin S Straley
- Chemical Engineering Department, Stanford University, Stanford, California 4305-4045, USA
| | | | | |
Collapse
|
44
|
Nemir S, West JL. Synthetic materials in the study of cell response to substrate rigidity. Ann Biomed Eng 2009; 38:2-20. [PMID: 19816774 DOI: 10.1007/s10439-009-9811-1] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 09/23/2009] [Indexed: 02/06/2023]
Abstract
While it has long been understood that cells can sense and respond to a variety of stimuli, including soluble and insoluble factors, light, and externally applied mechanical stresses, the extent to which cells can sense and respond to the mechanical properties of their environment has only recently begun to be studied. Cell response to substrate stiffness has been suggested to play an important role in processes ranging from developmental morphogenesis to the pathogenesis of disease states and may have profound implications for cell and tissue culture and tissue engineering. Given the importance of this phenomenon, there is a clear need for systems for cell study in which substrate mechanics can be carefully defined and varied independently of biochemical and other signals. This review will highlight past work in the field of cell response to substrate rigidity as well as areas for future study.
Collapse
Affiliation(s)
- Stephanie Nemir
- Department of Bioengineering, Rice University, 6100 Main St. MS 142, Houston, TX 77005, USA.
| | | |
Collapse
|
45
|
Nisbet DR, Rodda AE, Horne MK, Forsythe JS, Finkelstein DI. Neurite infiltration and cellular response to electrospun polycaprolactone scaffolds implanted into the brain. Biomaterials 2009; 30:4573-80. [DOI: 10.1016/j.biomaterials.2009.05.011] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Accepted: 05/10/2009] [Indexed: 10/20/2022]
|
46
|
Nerve fibroblast impact on Schwann cell behavior. Eur J Cell Biol 2009; 88:285-300. [PMID: 19246119 DOI: 10.1016/j.ejcb.2009.01.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 12/22/2008] [Accepted: 01/06/2009] [Indexed: 01/19/2023] Open
Abstract
In order to reveal non-neuronal cell interactions after peripheral nerve lesions, we began to analyze the impact of sciatic nerve fibroblasts on Schwann cells in vitro. Both cell types are considered to have opposite effects on axonal regeneration. Few data are available on how repulsive nerve fibroblasts affect neuritotrophic Schwann cells and thus might indirectly influence axonal regrowth. Using different culture systems in conjunction with time-lapse video recording, metabolic labeling, pharmacological intervention, RNAi knockdown, Western blotting and RT-PCR analysis, we found that nerve fibroblasts differentially modify the various responses of Schwann cells. In the presence of collagen type IV and heparan sulfate proteoglycan but not of laminin, diffusible fibroblast factors slow down Schwann cell proliferation. In contrast, fibroblast factors increase the migratory activity of Schwann cells without being chemoattractive. One pro-migratory fibroblast factor turned out to be neuregulin. The pro-migratory activity of nerve fibroblasts and of recombinant neuregulin-1beta1 can be counteracted by neuregulin-specific pharmacological intervention and by neuregulin RNA interference. We show for the first time that nerve fibroblasts play antagonistic and agonistic roles for Schwann cells in a context-dependent manner. The data shed light on cellular mechanisms and have implications for some neuro-tissue engineering strategies.
Collapse
|
47
|
Kempton LB, Gonzalez MH, Leven RM, Hughes WF, Beddow S, Santhiraj Y, Archibald SJ, El Hassan B, Shott S, Kerns JM. Assessment of Axonal Growth into Collagen Nerve Guides Containing VEGF-Transfected Stem Cells in Matrigel. Anat Rec (Hoboken) 2009; 292:214-24. [DOI: 10.1002/ar.20844] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
48
|
Kofron CM, Fong VJ, Hoffman-Kim D. Neurite outgrowth at the interface of 2D and 3D growth environments. J Neural Eng 2008; 6:016002. [DOI: 10.1088/1741-2560/6/1/016002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
49
|
Nisbet DR, Crompton KE, Horne MK, Finkelstein DI, Forsythe JS. Neural tissue engineering of the CNS using hydrogels. J Biomed Mater Res B Appl Biomater 2008; 87:251-63. [DOI: 10.1002/jbm.b.31000] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
50
|
Li GN, Hoffman-Kim D. Tissue-Engineered Platforms of Axon Guidance. TISSUE ENGINEERING PART B-REVIEWS 2008; 14:33-51. [DOI: 10.1089/teb.2007.0181] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Grace N. Li
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island
| | - Diane Hoffman-Kim
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island
| |
Collapse
|