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Ramos Ferrer P, Sakiyama-Elbert S. Affinity-based drug delivery systems for the central nervous system: exploiting molecular interactions for local, precise targeting. J Neural Eng 2024; 21:041004. [PMID: 39059438 DOI: 10.1088/1741-2552/ad680a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 07/26/2024] [Indexed: 07/28/2024]
Abstract
Objective: The effective treatment of central nervous system (CNS) disorders remains a significant challenge, primarily due to its molecular and structural complexity. Clinical translation of promising therapeutic agents is limited by the lack of optimal drug delivery systems capable of targeted, localized release of drugs to the brain and spinal cord.Approach: This review provides an overview of the potential of affinity-based drug delivery systems, which leverage molecular interactions to enhance the delivery and efficacy of therapeutic agents within the CNS.Main results: Various approaches, including hydrogels, micro- and nanoparticles, and functionalized biomaterials, are examined for their ability to provide local, sustained release of proteins, growth factors and other drugs.Significance: Furthermore, we present a detailed analysis of design considerations for developing effective affinity-based systems, incorporating insights from both existing literature and our group's research. These considerations include the biochemical modification of delivery vehicles and the optimization of physical and chemical properties to improve therapeutic outcomes.
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Affiliation(s)
- Pablo Ramos Ferrer
- Department of Chemical Engineering, University of Washington, Seattle, WA, United States of America
| | - Shelly Sakiyama-Elbert
- Department of Chemical Engineering, University of Washington, Seattle, WA, United States of America
- Department of Bioengineering, University of Washington, Seattle, WA, United States of America
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2
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Ramos Ferrer P, Vardhan S, Sakiyama-Elbert S. Sustained neurotrophin-3 delivery from hyaluronic acid hydrogels for neural tissue regeneration. J Biomed Mater Res A 2024; 112:1188-1199. [PMID: 37675824 DOI: 10.1002/jbm.a.37596] [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: 06/07/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 09/08/2023]
Abstract
The goal of this work was to design a polymer-based platform capable of localized, long-term delivery of biologically active neurotropic factors using an affinity-based approach. Here, we synthesized hyaluronic acid-methylfuran (HA-mF) hydrogels that provide sustained, affinity-based release of neurotrophin-3 (NT-3), a growth factor that promotes axon growth for 28 days. A Diels-Alder crosslinking reaction between HA-mF and polyethylene glycol (PEG)-dimaleimide occurs within 15 min under physiological conditions, resulting in hydrogels that can be polymerized in the presence of cells and growth factors. We also tuned the hydrogel's storage modulus to match that of native rat spinal cord tissue, providing a platform not only for localized drug delivery but also a suitable vehicle for cellular transplantation. The NT-3 released from the HAmF hydrogels remains bioactive for at least 14 days, promoting axonal growth from primary sensory neurons as well as stem cell-derived V2a interneurons and motoneurons in vitro. The hydrogels also supported cell growth allowing for 3-dimensional axonal extensions within the scaffold matrix. Here we confirm the protective role of HA-mF on matrix-bound NT-3 activity and show that these hydrogels are an excellent platform for growth factor delivery for neural applications.
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Affiliation(s)
- Pablo Ramos Ferrer
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
| | - Sangamithra Vardhan
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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3
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Galindo AN, Frey Rubio DA, Hettiaratchi MH. Biomaterial strategies for regulating the neuroinflammatory response. MATERIALS ADVANCES 2024; 5:4025-4054. [PMID: 38774837 PMCID: PMC11103561 DOI: 10.1039/d3ma00736g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 04/07/2024] [Indexed: 05/24/2024]
Abstract
Injury and disease in the central nervous system (CNS) can result in a dysregulated inflammatory environment that inhibits the repair of functional tissue. Biomaterials present a promising approach to tackle this complex inhibitory environment and modulate the mechanisms involved in neuroinflammation to halt the progression of secondary injury and promote the repair of functional tissue. In this review, we will cover recent advances in biomaterial strategies, including nanoparticles, hydrogels, implantable scaffolds, and neural probe coatings, that have been used to modulate the innate immune response to injury and disease within the CNS. The stages of inflammation following CNS injury and the main inflammatory contributors involved in common neurodegenerative diseases will be discussed, as understanding the inflammatory response to injury and disease is critical for identifying therapeutic targets and designing effective biomaterial-based treatment strategies. Biomaterials and novel composites will then be discussed with an emphasis on strategies that deliver immunomodulatory agents or utilize cell-material interactions to modulate inflammation and promote functional tissue repair. We will explore the application of these biomaterial-based strategies in the context of nanoparticle- and hydrogel-mediated delivery of small molecule drugs and therapeutic proteins to inflamed nervous tissue, implantation of hydrogels and scaffolds to modulate immune cell behavior and guide axon elongation, and neural probe coatings to mitigate glial scarring and enhance signaling at the tissue-device interface. Finally, we will present a future outlook on the growing role of biomaterial-based strategies for immunomodulation in regenerative medicine and neuroengineering applications in the CNS.
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Affiliation(s)
- Alycia N Galindo
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of Oregon Eugene OR USA
| | - David A Frey Rubio
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of Oregon Eugene OR USA
| | - Marian H Hettiaratchi
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of Oregon Eugene OR USA
- Department of Chemistry and Biochemistry, University of Oregon Eugene OR USA
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4
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Olteanu G, Neacșu SM, Joița FA, Musuc AM, Lupu EC, Ioniță-Mîndrican CB, Lupuliasa D, Mititelu M. Advancements in Regenerative Hydrogels in Skin Wound Treatment: A Comprehensive Review. Int J Mol Sci 2024; 25:3849. [PMID: 38612660 PMCID: PMC11012090 DOI: 10.3390/ijms25073849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
This state-of-the-art review explores the emerging field of regenerative hydrogels and their profound impact on the treatment of skin wounds. Regenerative hydrogels, composed mainly of water-absorbing polymers, have garnered attention in wound healing, particularly for skin wounds. Their unique properties make them well suited for tissue regeneration. Notable benefits include excellent water retention, creating a crucially moist wound environment for optimal healing, and facilitating cell migration, and proliferation. Biocompatibility is a key feature, minimizing adverse reactions and promoting the natural healing process. Acting as a supportive scaffold for cell growth, hydrogels mimic the extracellular matrix, aiding the attachment and proliferation of cells like fibroblasts and keratinocytes. Engineered for controlled drug release, hydrogels enhance wound healing by promoting angiogenesis, reducing inflammation, and preventing infection. The demonstrated acceleration of the wound healing process, particularly beneficial for chronic or impaired healing wounds, adds to their appeal. Easy application and conformity to various wound shapes make hydrogels practical, including in irregular or challenging areas. Scar minimization through tissue regeneration is crucial, especially in cosmetic and functional regions. Hydrogels contribute to pain management by creating a protective barrier, reducing friction, and fostering a soothing environment. Some hydrogels, with inherent antimicrobial properties, aid in infection prevention, which is a crucial aspect of successful wound healing. Their flexibility and ability to conform to wound contours ensure optimal tissue contact, enhancing overall treatment effectiveness. In summary, regenerative hydrogels present a promising approach for improving skin wound healing outcomes across diverse clinical scenarios. This review provides a comprehensive analysis of the benefits, mechanisms, and challenges associated with the use of regenerative hydrogels in the treatment of skin wounds. In this review, the authors likely delve into the application of rational design principles to enhance the efficacy and performance of hydrogels in promoting wound healing. Through an exploration of various methodologies and approaches, this paper is poised to highlight how these principles have been instrumental in refining the design of hydrogels, potentially revolutionizing their therapeutic potential in addressing skin wounds. By synthesizing current knowledge and highlighting potential avenues for future research, this review aims to contribute to the advancement of regenerative medicine and ultimately improve clinical outcomes for patients with skin wounds.
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Affiliation(s)
- Gabriel Olteanu
- Department of Clinical Laboratory and Food Safety, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania; (G.O.); (M.M.)
| | - Sorinel Marius Neacșu
- Department of Pharmaceutical Technology and Bio-Pharmacy, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020945 Bucharest, Romania; (S.M.N.); (D.L.)
| | - Florin Alexandru Joița
- Department of Pharmaceutical Technology and Bio-Pharmacy, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020945 Bucharest, Romania; (S.M.N.); (D.L.)
| | | | - Elena Carmen Lupu
- Department of Mathematics and Informatics, Faculty of Pharmacy, “Ovidius” University of Constanta, 900001 Constanta, Romania;
| | - Corina-Bianca Ioniță-Mîndrican
- Department of Toxicology, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020945 Bucharest, Romania;
| | - Dumitru Lupuliasa
- Department of Pharmaceutical Technology and Bio-Pharmacy, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020945 Bucharest, Romania; (S.M.N.); (D.L.)
| | - Magdalena Mititelu
- Department of Clinical Laboratory and Food Safety, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania; (G.O.); (M.M.)
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5
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Mullis AS, Kaplan DL. Functional bioengineered tissue models of neurodegenerative diseases. Biomaterials 2023; 298:122143. [PMID: 37146365 PMCID: PMC10209845 DOI: 10.1016/j.biomaterials.2023.122143] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 04/27/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023]
Abstract
Aging-associated neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases remain poorly understood and no disease-modifying treatments exist despite decades of investigation. Predominant in vitro (e.g., 2D cell culture, organoids) and in vivo (e.g., mouse) models of these diseases are insufficient mimics of human brain tissue structure and function and of human neurodegenerative pathobiology, and have thus contributed to this collective translational failure. This has been a longstanding challenge in the field, and new strategies are required to address both fundamental and translational needs. Bioengineered tissue culture models constitute a class of promising alternatives, as they can overcome the low cell density, poor nutrient exchange, and long term culturability limitations of existing in vitro models. Further, they can reconstruct the structural, mechanical, and biochemical cues of native brain tissue, providing a better mimic of human brain tissues for in vitro pathobiological investigation and drug development. We discuss bioengineering techniques for the generation of these neurodegenerative tissue models, including biomaterials-, organoid-, and microfluidics-based approaches, and design considerations for their construction. To aid the development of the next generation of functional neurodegenerative disease models, we discuss approaches to incorporate greater cellular diversity and simulate aging processes within bioengineered brain tissues.
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Affiliation(s)
- Adam S Mullis
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA.
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA; Allen Discovery Center, Tufts University, Medford, MA, 02155, USA.
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6
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Wang X, Ma Y, Lu F, Chang Q. The diversified hydrogels for biomedical applications and their imperative roles in tissue regeneration. Biomater Sci 2023; 11:2639-2660. [PMID: 36790251 DOI: 10.1039/d2bm01486f] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Repair and regeneration of tissues after injury are complex pathophysiological processes. Microbial infection, malnutrition, and an ischemic and hypoxic microenvironment in the injured area can impede the typical healing cascade. Distinguished by biomimicry of the extracellular matrix, high aqueous content, and diverse functions, hydrogels have revolutionized clinical practices in tissue regeneration owing to their outstanding hydrophilicity, biocompatibility, and biodegradability. Various hydrogels such as smart hydrogels, nanocomposite hydrogels, and acellular matrix hydrogels are widely used for applications ranging from bench-scale to an industrial scale. In this review, some emerging hydrogels in the biomedical field are briefly discussed. The protective roles of hydrogels in wound dressings and their diverse biological effects on multiple tissues such as bone, cartilage, nerve, muscle, and adipose tissue are also discussed. The vehicle functions of hydrogels for chemicals and cell payloads are detailed. Additionally, this review emphasizes the particular characteristics of hydrogel products that promote tissue repair and reconstruction such as anti-infection, inflammation regulation, and angiogenesis.
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Affiliation(s)
- Xinhui Wang
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, 510515, China.
| | - Yuan Ma
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, 510515, China.
| | - Feng Lu
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, 510515, China.
| | - Qiang Chang
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, 510515, China.
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7
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Visser Z, Verma SK, Rainey JK, Frampton JP. Loading and Release of Quercetin from Contact-Drawn Polyvinyl Alcohol Fiber Scaffolds. ACS Pharmacol Transl Sci 2022; 5:1305-1317. [PMID: 36524014 PMCID: PMC9745892 DOI: 10.1021/acsptsci.2c00191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Indexed: 11/30/2022]
Abstract
Polymeric drug releasing systems have numerous applications for the treatment of chronic diseases and traumatic injuries. In this study, a simple, cost-effective, and scalable method for dry spinning of crosslinked polyvinyl alcohol (PVA) fibers is presented. This method utilizes an entangled solution of PVA to form liquid bridges that are drawn into rapidly drying fibers through extensional flow. The fibers are crosslinked by a one-pot reaction in which glyoxal is introduced to the PVA solution prior to contact drawing. Failure analysis of fiber formation is used to understand the interplay of polymer concentration, glyoxal concentration, and crosslinking time to identify appropriate formulations for the production of glyoxal-crosslinked PVA fibers. The small molecule quercetin (an anti-inflammatory plant flavonoid) can be added to the one-pot reaction and is shown to be incorporated into the fibers in a concentration-dependent manner. Upon rehydration in an aqueous medium, the glyoxal-crosslinked PVA fiber scaffolds retain their morphology and slowly degrade, as measured over the course of 10 days. As the scaffolds degrade, they release the loaded quercetin, reaching a cumulative release of 56 ± 6% of the loaded drug after 10 days. The bioactivity of the released quercetin is verified by combining quercetin-loaded fibers with contact-drawn polyethylene oxide-type I collagen (PEO-Col) fibers and monitoring the growth of PC12 cells on the fibers. PC12 cells readily attach to the PEO-Col fibers and display increased nerve growth factor-induced elongation and neurite formation in the presence of quercetin-loaded PVA fibers relative to substrates formed from only PEO-Col fibers or PEO-Col and PVA fibers without quercetin.
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Affiliation(s)
- Zachary
B. Visser
- School
of Biomedical Engineering, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
| | - Surendra Kumar Verma
- School
of Biomedical Engineering, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
| | - Jan K. Rainey
- School
of Biomedical Engineering, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
- Department
of Biochemistry & Molecular Biology, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
- Department
of Chemistry, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
| | - John P. Frampton
- School
of Biomedical Engineering, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
- Department
of Biochemistry & Molecular Biology, Dalhousie University, HalifaxB3H 4R2, Nova Scotia, Canada
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8
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Bertsch P, Diba M, Mooney DJ, Leeuwenburgh SCG. Self-Healing Injectable Hydrogels for Tissue Regeneration. Chem Rev 2022; 123:834-873. [PMID: 35930422 PMCID: PMC9881015 DOI: 10.1021/acs.chemrev.2c00179] [Citation(s) in RCA: 177] [Impact Index Per Article: 88.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Biomaterials with the ability to self-heal and recover their structural integrity offer many advantages for applications in biomedicine. The past decade has witnessed the rapid emergence of a new class of self-healing biomaterials commonly termed injectable, or printable in the context of 3D printing. These self-healing injectable biomaterials, mostly hydrogels and other soft condensed matter based on reversible chemistry, are able to temporarily fluidize under shear stress and subsequently recover their original mechanical properties. Self-healing injectable hydrogels offer distinct advantages compared to traditional biomaterials. Most notably, they can be administered in a locally targeted and minimally invasive manner through a narrow syringe without the need for invasive surgery. Their moldability allows for a patient-specific intervention and shows great prospects for personalized medicine. Injected hydrogels can facilitate tissue regeneration in multiple ways owing to their viscoelastic and diffusive nature, ranging from simple mechanical support, spatiotemporally controlled delivery of cells or therapeutics, to local recruitment and modulation of host cells to promote tissue regeneration. Consequently, self-healing injectable hydrogels have been at the forefront of many cutting-edge tissue regeneration strategies. This study provides a critical review of the current state of self-healing injectable hydrogels for tissue regeneration. As key challenges toward further maturation of this exciting research field, we identify (i) the trade-off between the self-healing and injectability of hydrogels vs their physical stability, (ii) the lack of consensus on rheological characterization and quantitative benchmarks for self-healing injectable hydrogels, particularly regarding the capillary flow in syringes, and (iii) practical limitations regarding translation toward therapeutically effective formulations for regeneration of specific tissues. Hence, here we (i) review chemical and physical design strategies for self-healing injectable hydrogels, (ii) provide a practical guide for their rheological analysis, and (iii) showcase their applicability for regeneration of various tissues and 3D printing of complex tissues and organoids.
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Affiliation(s)
- Pascal Bertsch
- Department
of Dentistry-Regenerative Biomaterials, Radboud Institute for Molecular
Life Sciences, Radboud University Medical
Center, 6525 EX Nijmegen, The Netherlands
| | - Mani Diba
- Department
of Dentistry-Regenerative Biomaterials, Radboud Institute for Molecular
Life Sciences, Radboud University Medical
Center, 6525 EX Nijmegen, The Netherlands,John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States,Wyss
Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, United States
| | - David J. Mooney
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States,Wyss
Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts 02115, United States
| | - Sander C. G. Leeuwenburgh
- Department
of Dentistry-Regenerative Biomaterials, Radboud Institute for Molecular
Life Sciences, Radboud University Medical
Center, 6525 EX Nijmegen, The Netherlands,
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9
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Pinelli F, Pizzetti F, Veneruso V, Petillo E, Raghunath M, Perale G, Veglianese P, Rossi F. Biomaterial-Mediated Factor Delivery for Spinal Cord Injury Treatment. Biomedicines 2022; 10:biomedicines10071673. [PMID: 35884981 PMCID: PMC9313204 DOI: 10.3390/biomedicines10071673] [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: 04/28/2022] [Revised: 05/24/2022] [Accepted: 07/05/2022] [Indexed: 11/19/2022] Open
Abstract
Spinal cord injury (SCI) is an injurious process that begins with immediate physical damage to the spinal cord and associated tissues during an acute traumatic event. However, the tissue damage expands in both intensity and volume in the subsequent subacute phase. At this stage, numerous events exacerbate the pathological condition, and therein lies the main cause of post-traumatic neural degeneration, which then ends with the chronic phase. In recent years, therapeutic interventions addressing different neurodegenerative mechanisms have been proposed, but have met with limited success when translated into clinical settings. The underlying reasons for this are that the pathogenesis of SCI is a continued multifactorial disease, and the treatment of only one factor is not sufficient to curb neural degeneration and resulting paralysis. Recent advances have led to the development of biomaterials aiming to promote in situ combinatorial strategies using drugs/biomolecules to achieve a maximized multitarget approach. This review provides an overview of single and combinatorial regenerative-factor-based treatments as well as potential delivery options to treat SCIs.
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Affiliation(s)
- Filippo Pinelli
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milan, Italy; (F.P.); (F.P.); (E.P.)
| | - Fabio Pizzetti
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milan, Italy; (F.P.); (F.P.); (E.P.)
| | - Valeria Veneruso
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy;
| | - Emilia Petillo
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milan, Italy; (F.P.); (F.P.); (E.P.)
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy;
| | - Michael Raghunath
- Center for Cell Biology and Tissue Engineering, Institute for Chemistry and Biotechnology (ICBT), Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland;
| | - Giuseppe Perale
- Faculty of Biomedical Sciences, University of Southern Switzerland (USI), Via Buffi 13, 6900 Lugano, Switzerland;
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Donaueschingenstrasse 13, 1200 Vienna, Austria
| | - Pietro Veglianese
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy;
- Correspondence: (P.V.); (F.R.); Tel.: +39-02-3901-4205 (P.V.); +39-02-2399-3145 (F.R.)
| | - Filippo Rossi
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milan, Italy; (F.P.); (F.P.); (E.P.)
- Correspondence: (P.V.); (F.R.); Tel.: +39-02-3901-4205 (P.V.); +39-02-2399-3145 (F.R.)
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10
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Nance E, Pun SH, Saigal R, Sellers DL. Drug delivery to the central nervous system. NATURE REVIEWS. MATERIALS 2022; 7:314-331. [PMID: 38464996 PMCID: PMC10923597 DOI: 10.1038/s41578-021-00394-w] [Citation(s) in RCA: 84] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/05/2021] [Indexed: 03/12/2024]
Abstract
Despite the rising global incidence of central nervous system (CNS) disorders, CNS drug development remains challenging, with high costs, long pathways to clinical use and high failure rates. The CNS is highly protected by physiological barriers, in particular, the blood-brain barrier and the blood-cerebrospinal fluid barrier, which limit access of most drugs. Biomaterials can be designed to bypass or traverse these barriers, enabling the controlled delivery of drugs into the CNS. In this Review, we first examine the effects of normal and diseased CNS physiology on drug delivery to the brain and spinal cord. We then discuss CNS drug delivery designs and materials that are administered systemically, directly to the CNS, intranasally or peripherally through intramuscular injections. Finally, we highlight important challenges and opportunities for materials design for drug delivery to the CNS and the anticipated clinical impact of CNS drug delivery.
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Affiliation(s)
- Elizabeth Nance
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
- These authors contributed equally: Elizabeth Nance, Suzie H. Pun, Rajiv Saigal, Drew L. Sellers
| | - Suzie H. Pun
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- These authors contributed equally: Elizabeth Nance, Suzie H. Pun, Rajiv Saigal, Drew L. Sellers
| | - Rajiv Saigal
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
- These authors contributed equally: Elizabeth Nance, Suzie H. Pun, Rajiv Saigal, Drew L. Sellers
| | - Drew L. Sellers
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- These authors contributed equally: Elizabeth Nance, Suzie H. Pun, Rajiv Saigal, Drew L. Sellers
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11
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Development of a New Formulation Based on In Situ Photopolymerized Polymer for the Treatment of Spinal Cord Injury. Polymers (Basel) 2021; 13:polym13244274. [PMID: 34960825 PMCID: PMC8705720 DOI: 10.3390/polym13244274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 12/04/2022] Open
Abstract
Spinal Cord Injury (SCI) promotes a cascade of inflammatory events that are responsible for neuronal death and glial scar formation at the site of the injury, hindering tissue neuroregeneration. Among the main approaches for the treatment of SCI, the use of biomaterials, especially gelatin methacryloyl (GelMA), has been proposed because it is biocompatible, has excellent mechanical properties, favoring cell adhesion and proliferation. In addition, it can act as a carrier of anti-inflammatory drugs, preventing the formation of glial scars. The present work presents the development and in situ application of a light-curing formulation based on GelMA containing a natural extract rich in anti-inflammatory, antioxidant and neuroprotective substances (hydroalcoholic extract of red propolis—HERP) in an experimental model of SCI in rats. The formulations were prepared and characterized by time of UV exposition, FTIR, swelling and degradation. The hydrogels containing 1 mg/mL of HERP were obtained by the exposure to UV radiation of 2 μL of the formulation for 60 s. The locomotor evaluation of the animals was performed by the scale (BBB) and demonstrated that after 3 and 7 days of the injury, the GelMA-HERP group (BBB = 5 and 7) presented greater recovery compared to the GelMA group (BBB = 4 and 5). Regarding the inflammatory process, using histomorphological techniques, there was an inflammation reduction in the groups treated with GelMA and GelMA-HERP, with decreases of cavitation in the injury site. Therefore, it is possible to conclude that the use of GelMA and GelMA-HERP hydrogel formulations is a promising strategy for the treatment of SCI when applied in situ, as soon as possible after the injury, improving the clinical and inflammatory conditions of the treated animals.
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12
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Matthews J, Surey S, Grover LM, Logan A, Ahmed Z. Thermosensitive collagen/fibrinogen gels loaded with decorin suppress lesion site cavitation and promote functional recovery after spinal cord injury. Sci Rep 2021; 11:18124. [PMID: 34518601 PMCID: PMC8438067 DOI: 10.1038/s41598-021-97604-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/27/2021] [Indexed: 11/10/2022] Open
Abstract
The treatment of spinal cord injury (SCI) is a complex challenge in regenerative medicine, complicated by the low intrinsic capacity of CNS neurons to regenerate their axons and the heterogeneity in size, shape and extent of human injuries. For example, some contusion injuries do not compromise the dura mater and in such cases implantation of preformed scaffolds or drug delivery systems may cause further damage. Injectable in situ thermosensitive scaffolds are therefore a less invasive alternative. In this study, we report the development of a novel, flowable, thermosensitive, injectable drug delivery system comprising bovine collagen (BC) and fibrinogen (FB) that forms a solid BC/FB gel (Gel) immediately upon exposure to physiological conditions and can be used to deliver reparative drugs, such as the naturally occurring anti-inflammatory, anti-scarring agent Decorin, into adult rat spinal cord lesion sites. In dorsal column lesions of adult rats treated with the Gel + Decorin, cavitation was completely suppressed and instead lesion sites became filled with injury-responsive cells and extracellular matrix materials, including collagen and laminin. Decorin increased the intrinsic potential of dorsal root ganglion neurons (DRGN) by increasing their expression of regeneration associated genes (RAGs), enhanced local axon regeneration/sprouting, as evidenced both histologically and by improved electrophysiological, locomotor and sensory function recovery. These results suggest that this drug formulated, injectable hydrogel has the potential to be further studied and translated into the clinic.
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Affiliation(s)
- Jacob Matthews
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Sarina Surey
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Liam M Grover
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Ann Logan
- Warwick Medical School, Biomedical Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. .,Centre for Trauma Sciences Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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13
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Tejeda G, Ciciriello AJ, Dumont CM. Biomaterial Strategies to Bolster Neural Stem Cell-Mediated Repair of the Central Nervous System. Cells Tissues Organs 2021; 211:655-669. [PMID: 34120118 DOI: 10.1159/000515351] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/12/2021] [Indexed: 01/25/2023] Open
Abstract
Stem cell therapies have the potential to not only repair, but to regenerate tissue of the central nervous system (CNS). Recent studies demonstrate that transplanted stem cells can differentiate into neurons and integrate with the intact circuitry after traumatic injury. Unfortunately, the positive findings described in rodent models have not been replicated in clinical trials, where the burden to maintain the cell viability necessary for tissue repair becomes more challenging. Low transplant survival remains the greatest barrier to stem cell-mediated repair of the CNS, often with fewer than 1-2% of the transplanted cells remaining after 1 week. Strategic transplantation parameters, such as injection location, cell concentration, and transplant timing achieve only modest improvements in stem cell transplant survival and appear inconsistent across studies. Biomaterials provide researchers with a means to significantly improve stem cell transplant survival through two mechanisms: (1) a vehicle to deliver and protect the stem cells and (2) a substrate to control the cytotoxic injury environment. These biomaterial strategies can alleviate cell death associated with delivery to the injury and can be used to limit cell death after transplantation by limiting cell exposure to cytotoxic signals. Moreover, it is likely that control of the injury environment with biomaterials will lead to a more reliable support for transplanted cell populations. This review will highlight the challenges associated with cell delivery in the CNS and the advances in biomaterial development and deployment for stem cell therapies necessary to bolster stem cell-mediated repair.
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Affiliation(s)
- Giancarlo Tejeda
- Department of Biomedical Engineering, University of Miami, Coral Gables, Florida, USA.,Biomedical Nanotechnology Institute at the University of Miami (BioNIUM), University of Miami, Miami, Florida, USA
| | - Andrew J Ciciriello
- Department of Biomedical Engineering, University of Miami, Coral Gables, Florida, USA.,Biomedical Nanotechnology Institute at the University of Miami (BioNIUM), University of Miami, Miami, Florida, USA
| | - Courtney M Dumont
- Department of Biomedical Engineering, University of Miami, Coral Gables, Florida, USA.,Biomedical Nanotechnology Institute at the University of Miami (BioNIUM), University of Miami, Miami, Florida, USA
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14
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Muheremu A, Shu L, Liang J, Aili A, Jiang K. Sustained delivery of neurotrophic factors to treat spinal cord injury. Transl Neurosci 2021; 12:494-511. [PMID: 34900347 PMCID: PMC8633588 DOI: 10.1515/tnsci-2020-0200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 12/16/2022] Open
Abstract
Acute spinal cord injury (SCI) is a devastating condition that results in tremendous physical and psychological harm and a series of socioeconomic problems. Although neurons in the spinal cord need neurotrophic factors for their survival and development to reestablish their connections with their original targets, endogenous neurotrophic factors are scarce and the sustainable delivery of exogeneous neurotrophic factors is challenging. The widely studied neurotrophic factors such as brain-derived neurotrophic factor, neurotrophin-3, nerve growth factor, ciliary neurotrophic factor, basic fibroblast growth factor, and glial cell-derived neurotrophic factor have a relatively short cycle that is not sufficient enough for functionally significant neural regeneration after SCI. In the past decades, scholars have tried a variety of cellular and viral vehicles as well as tissue engineering scaffolds to safely and sustainably deliver those necessary neurotrophic factors to the injury site, and achieved satisfactory neural repair and functional recovery on many occasions. Here, we review the neurotrophic factors that have been used in trials to treat SCI, and vehicles that were commonly used for their sustained delivery.
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Affiliation(s)
- Aikeremujiang Muheremu
- Department of Spine Surgery, Sixth Affiliated Hospital of Xinjiang Medical University, 39 Wuxing Nan Rd, Tianshan District, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Li Shu
- Department of Orthopedics, Sixth Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Jing Liang
- Department of Laboratory Medicine, Sixth Affiliated Hospital of Xinjiang Medical University, 39, Wuxing Nan Rd, Tianshan District, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Abudunaibi Aili
- Department of Spine Surgery, Sixth Affiliated Hospital of Xinjiang Medical University, 39 Wuxing Nan Rd, Tianshan District, Urumqi, Xinjiang, 86830001, People’s Republic of China
| | - Kan Jiang
- Department of Orthopedics, Sixth Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 86830001, People’s Republic of China
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15
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Abstract
Spinal cord injury results in significant loss of motor, sensory, and autonomic functions. Although a wide range of therapeutic agents have been shown to attenuate secondary injury or promote regeneration/repair in animal models of spinal cord injury, clinical translation of these strategies has been limited, in part due to difficulty in safely and effectively achieving therapeutic concentrations in the injured spinal cord tissue. Hydrogel-based drug delivery systems offer unique opportunities to locally deliver drugs to the injured spinal cord with sufficient dose and duration, while avoiding deleterious side effects associated with systemic drug administration. Such local drug delivery systems can be readily fabricated from biocompatible and biodegradable materials. In this review, hydrogel-based strategies for local drug delivery to the injured spinal cord are extensively reviewed, and recommendations are made for implementation.
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Affiliation(s)
- Robert B Shultz
- School of Biomedical Engineering, Science and Health Systems, Drexel University; Department of Neurosurgery; Department of Bioengineering, University of Pennsylvania; New Jersey Center for Biomaterials, Rutgers - The State University of New Jersey, Piscataway, NJ; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - Yinghui Zhong
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
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16
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Silva D, Sousa R, Salgado A. Hydrogels as delivery systems for spinal cord injury regeneration. Mater Today Bio 2021; 9:100093. [PMID: 33665602 PMCID: PMC7905359 DOI: 10.1016/j.mtbio.2021.100093] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 01/04/2023] Open
Abstract
Spinal cord injury is extremely debilitating, both at physiological and psychological levels, changing completely the patient's lifestyle. The introduction of biomaterials has opened a new window to develop a therapeutic approach to induce regeneration after injury due to similarities with extracellular matrix. Particularly, hydrogels have the ability to support axonal growth and endogenous regeneration. Moreover, they can also act as potential matrixes in which to load and deliver therapeutic agents at injury site. In this review, we highlight some important characteristics to be considered when designing hydrogels as delivery systems (DS), such as rheology, mesh size, swelling, degradation, gelation temperature and surface charge. Additionally, affinity-based release systems, incorporation of nanoparticles, or ion-mediated interactions are also pondered. Overall, hydrogel DS aim to promote a sustained, controlled and prolonged release at injury site, allowing a targeted oriented action of the therapeutic agent that will be used.
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Affiliation(s)
- D. Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
- ICVS/3B's—PT Government Associate Laboratory, 4710-057/4805-017, Braga/Guimarães, Portugal
- Stemmatters, Biotecnologia e Medicina Regenerativa SA, 4805-017, Guimarães, Portugal
| | - R.A. Sousa
- Stemmatters, Biotecnologia e Medicina Regenerativa SA, 4805-017, Guimarães, Portugal
| | - A.J. Salgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
- ICVS/3B's—PT Government Associate Laboratory, 4710-057/4805-017, Braga/Guimarães, Portugal
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17
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Bae M, Yi HG, Jang J, Cho DW. Microphysiological Systems for Neurodegenerative Diseases in Central Nervous System. MICROMACHINES 2020; 11:E855. [PMID: 32947879 PMCID: PMC7570039 DOI: 10.3390/mi11090855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022]
Abstract
Neurodegenerative diseases are among the most severe problems in aging societies. Various conventional experimental models, including 2D and animal models, have been used to investigate the pathogenesis of (and therapeutic mechanisms for) neurodegenerative diseases. However, the physiological gap between humans and the current models remains a hurdle to determining the complexity of an irreversible dysfunction in a neurodegenerative disease. Therefore, preclinical research requires advanced experimental models, i.e., those more physiologically relevant to the native nervous system, to bridge the gap between preclinical stages and patients. The neural microphysiological system (neural MPS) has emerged as an approach to summarizing the anatomical, biochemical, and pathological physiology of the nervous system for investigation of neurodegenerative diseases. This review introduces the components (such as cells and materials) and fabrication methods for designing a neural MPS. Moreover, the review discusses future perspectives for improving the physiological relevance to native neural systems.
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Affiliation(s)
- Mihyeon Bae
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Chungam-ro, Nam-gu, Pohang 37673, Korea;
| | - Hee-Gyeong Yi
- Department of Rural and Biosystems Engineering, College of Agricultural Sciences, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Korea
| | - Jinah Jang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Chungam-ro, Nam-gu, Pohang 37673, Korea;
- Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Chungam-ro, Nam-gu, Pohang 37673, Korea
- Institute of Convergence Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Dong-Woo Cho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Chungam-ro, Nam-gu, Pohang 37673, Korea;
- Institute of Convergence Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
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18
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Prabhu S, Bubbly SG, Gudennavar SB. Synthetic polymer hydrogels as potential tissue phantoms in radiation therapy and dosimetry. Biomed Phys Eng Express 2020; 6:055008. [PMID: 33444239 DOI: 10.1088/2057-1976/aba209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The efficacy of synthetic polymers as hydrogel phantoms for radiation therapy and dosimetry has been investigated for photon and charged particle (electron, proton and alpha particle) interactions. Tissue equivalence has been studied in terms of photon mass energy-absorption coefficients, KERMA (kinetic energy released per unit mass), equivalent atomic number and energy absorption build-up factors, relative to human tissues (skin, soft tissue, cortical bone and skeletal muscle), in the energy range 0.015-15 MeV. For charged particle interactions, ratio of effective atomic number is examined for tissue-equivalence in the energy region of 10 keV-1 GeV. Well established theoretical formulations are used for computation of photon mass-energy absorption effective atomic number, electron density and KERMA. Five-parameter geometric progression (G-P) fitting approximation is used to compute the values of energy absorption build-up factors. Effective atomic number for charged particle interaction is determined using logarithmic interpolation method. Using the analytical methodology, it has been revealed that all the selected synthetic polymers have good tissue-equivalence relative to all tissue except cortical bone. In particular, polyglycolic acid (PGA) and poly-lactic-co-glycolic acid (PLGA) prove to be best substitute material for photon interactions. On the other hand, % difference between effective atomic number for charged particle relative to human tissues is found least for polyethylene glycol (PEG) demonstrating adequate tissue-equivalence. Therefore, the present study is expected to be useful to choose most appropriate phantom material for radiation therapy.
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Affiliation(s)
- Srilakshmi Prabhu
- Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore Central Campus, Bengaluru - 560029, Karnataka, India
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19
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Harris JM, Wang AYD, Boulanger-Weill J, Santoriello C, Foianini S, Lichtman JW, Zon LI, Arlotta P. Long-Range Optogenetic Control of Axon Guidance Overcomes Developmental Boundaries and Defects. Dev Cell 2020; 53:577-588.e7. [PMID: 32516597 PMCID: PMC7375170 DOI: 10.1016/j.devcel.2020.05.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 03/12/2020] [Accepted: 05/11/2020] [Indexed: 01/12/2023]
Abstract
Axons connect neurons together, establishing the wiring architecture of neuronal networks. Axonal connectivity is largely built during embryonic development through highly constrained processes of axon guidance, which have been extensively studied. However, the inability to control axon guidance, and thus neuronal network architecture, has limited investigation of how axonal connections influence subsequent development and function of neuronal networks. Here, we use zebrafish motor neurons expressing a photoactivatable Rac1 to co-opt endogenous growth cone guidance machinery to precisely and non-invasively direct axon growth using light. Axons can be guided over large distances, within complex environments of living organisms, overriding competing endogenous signals and redirecting axons across potent repulsive barriers to construct novel circuitry. Notably, genetic axon guidance defects can be rescued, restoring functional connectivity. These data demonstrate that intrinsic growth cone guidance machinery can be co-opted to non-invasively build new connectivity, allowing investigation of neural network dynamics in intact living organisms.
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Affiliation(s)
- James M. Harris
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA.,Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, MA 02115, USA.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02138, USA
| | - Andy Yu-Der Wang
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA.,Current Address: Tufts University School of Medicine, Boston, MA 02115, USA
| | - Jonathan Boulanger-Weill
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Cristina Santoriello
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA.,Stem Cell Program and Division of Hematology/Oncology, Children’s Hospital and Dana Farber Cancer Institute, Howard Hughes Medical Institute, Harvard Medical School, Harvard Stem Cell Institute, Stem Cell and Regenerative Biology Department, Harvard University, Boston, MA 02115, USA
| | - Stephan Foianini
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Jeff W. Lichtman
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.,Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Leonard I. Zon
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA.,Stem Cell Program and Division of Hematology/Oncology, Children’s Hospital and Dana Farber Cancer Institute, Howard Hughes Medical Institute, Harvard Medical School, Harvard Stem Cell Institute, Stem Cell and Regenerative Biology Department, Harvard University, Boston, MA 02115, USA
| | - Paola Arlotta
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02138, USA.,Lead contact. Correspondence:
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20
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Lee J, Zhao T, Peeler DJ, Lee DC, Pichon TJ, Li D, Weigandt KM, Horner PJ, Pozzo LD, Sellers DL, Pun SH. Formulation of thrombin-inhibiting hydrogels via self-assembly of ionic peptides with peptide-modified polymers. SOFT MATTER 2020; 16:3762-3768. [PMID: 32239011 PMCID: PMC7204513 DOI: 10.1039/d0sm00209g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cell therapy for spinal cord injuries offers the possibility of replacing lost cells after trauma to the central nervous system (CNS). In preclinical studies, synthetic hydrogels are often co-delivered to the injury site to support survival and integration of the transplanted cells. These hydrogels ideally mimic the mechanical and biochemical features of a healthy CNS extracellular matrix while also providing the possibility of localized drug delivery to promote healing. In this work, we synthesize peptide-functionalized polymers that contain both a peptide sequence for incorporation into self-assembled peptide hydrogels along with bioactive peptides that inhibit scar formation. We demonstrate that peptide hydrogels formulated with the peptide-functionalized polymers possess similar mechanical properties (soft and shear-thinning) as peptide-only hydrogels. Small angle neutron scattering analysis reveals that polymer-containing hydrogels possess larger inhomogeneous domains but small-scale features such as mesh size remain the same as peptide-only hydrogels. We further confirm that the integrated hydrogels containing bioactive peptides exhibit thrombin inhibition activity, which has previously shown to reduce scar formation in vivo. Finally, while the survival of encapsulated cells was poor, cells cultured on the hydrogels exhibited good viability. Overall, the described composite hydrogels formed from self-assembling peptides and peptide-modified polymers are promising, user-friendly materials for CNS applications in regeneration.
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Affiliation(s)
- Jason Lee
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
| | - Tianyu Zhao
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
| | - David J Peeler
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
| | - Daniel C Lee
- Molecular Engineering and Sciences, University of Washington, Seattle, WA 98195, USA
| | - Trey J Pichon
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
| | - David Li
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA
| | - Kathleen M Weigandt
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Philip J Horner
- Center for Neuroregeneration and Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Lilo D Pozzo
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA
| | - Drew L Sellers
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
| | - Suzie H Pun
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA. and Molecular Engineering and Sciences, University of Washington, Seattle, WA 98195, USA
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21
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Motor and sensitive recovery after injection of a physically cross-linked PNIPAAm-g-PEG hydrogel in rat hemisectioned spinal cord. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 107:110354. [DOI: 10.1016/j.msec.2019.110354] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/02/2019] [Accepted: 10/20/2019] [Indexed: 12/28/2022]
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22
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Madhusudanan P, Raju G, Shankarappa S. Hydrogel systems and their role in neural tissue engineering. J R Soc Interface 2020; 17:20190505. [PMID: 31910776 PMCID: PMC7014813 DOI: 10.1098/rsif.2019.0505] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 12/02/2019] [Indexed: 12/27/2022] Open
Abstract
Neural tissue engineering (NTE) is a rapidly progressing field that promises to address several serious neurological conditions that are currently difficult to treat. Selecting the right scaffolding material to promote neural and non-neural cell differentiation as well as axonal growth is essential for the overall design strategy for NTE. Among the varieties of scaffolds, hydrogels have proved to be excellent candidates for culturing and differentiating cells of neural origin. Considering the intrinsic resistance of the nervous system against regeneration, hydrogels have been abundantly used in applications that involve the release of neurotrophic factors, antagonists of neural growth inhibitors and other neural growth-promoting agents. Recent developments in the field include the utilization of encapsulating hydrogels in neural cell therapy for providing localized trophic support and shielding neural cells from immune activity. In this review, we categorize and discuss the various hydrogel-based strategies that have been examined for neural-specific applications and also highlight their strengths and weaknesses. We also discuss future prospects and challenges ahead for the utilization of hydrogels in NTE.
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Affiliation(s)
| | | | - Sahadev Shankarappa
- Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Center, Amrita Vishwa Vidyapeetham, Kochi 682041, India
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23
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Grijalvo S, Nieto‐Díaz M, Maza RM, Eritja R, Díaz DD. Alginate Hydrogels as Scaffolds and Delivery Systems to Repair the Damaged Spinal Cord. Biotechnol J 2019; 14:e1900275. [DOI: 10.1002/biot.201900275] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 10/12/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Santiago Grijalvo
- Institute for Advanced Chemistry of Catalonia (IQAC, CSIC) Jordi Girona 18–26 E‐08034 Barcelona Spain
- Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER‐BBN) Jordi Girona 18–26 E‐08034 Barcelona Spain
| | - Manuel Nieto‐Díaz
- Molecular Neuroprotection GroupResearch Unit, National Hospital for Paraplegics (SESCAM) E‐45071 Toledo Spain
| | - Rodrigo M. Maza
- Molecular Neuroprotection GroupResearch Unit, National Hospital for Paraplegics (SESCAM) E‐45071 Toledo Spain
| | - Ramón Eritja
- Institute for Advanced Chemistry of Catalonia (IQAC, CSIC) Jordi Girona 18–26 E‐08034 Barcelona Spain
- Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER‐BBN) Jordi Girona 18–26 E‐08034 Barcelona Spain
| | - David Díaz Díaz
- Institut für Organische ChemieUniversität Regensburg, Universitätsstr. 31 93053 Regensburg Germany
- Institute of Natural Products and Abrobiology of the CSIC Avda. Astrofísico Francisco Sánchez 3 E‐3826 La Laguna Tenerife Spain
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24
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Zhou P, Guan J, Xu P, Zhao J, Zhang C, Zhang B, Mao Y, Cui W. Cell Therapeutic Strategies for Spinal Cord Injury. Adv Wound Care (New Rochelle) 2019; 8:585-605. [PMID: 31637103 PMCID: PMC6798812 DOI: 10.1089/wound.2019.1046] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 08/27/2019] [Indexed: 12/13/2022] Open
Abstract
Significance: Spinal cord injury (SCI) is a neurological disorder that resulted from destroyed long axis of spinal cord, affecting thousands of people every year. With the occurrence of SCI, the lesions can form cystic cavities and produce glial scar, myelin inhibitor, and inflammation that negatively impact repair of spinal cord. Therefore, SCI remains a difficult problem to overcome with present therapeutics. This review of cell therapeutics in SCI provides a systematic review of combinatory therapeutics of SCI and helps the realization of regeneration of spinal cord in the future. Recent Advances: With major breakthroughs in neurobiology in recent years, present therapeutic strategies for SCI mainly aim at nerve regeneration or neuroprotection. For nerve regeneration, the application approaches are tissue engineering and cell transplantation, while drug therapeutics is applied for neuroprotection. Cell therapeutics is a new approach that treats SCI by cell transplantation. Cell therapeutics possesses advantages of neuroprotection, immune regulation, axonal regeneration, neuron relay formation, and remyelination. Critical Issues: Neurons cannot regenerate at the site of injury. Therefore, it is essential to find a repair strategy for remyelination, axon regeneration, and functional recovery. Cell therapeutics is emerging as the most promising approach for treating SCI. Future Directions: The future application of SCI therapy in clinical practice may require a combination of multiple strategies. A comprehensive treatment of injury of spinal cord is the focus of the present research. With the combination of different cell therapy strategies, future experiments will achieve more dramatic success in spinal cord repair.
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Affiliation(s)
- Pinghui Zhou
- Department of Orthopedics, First Affiliated Hospital of Bengbu Medical College, Bengbu, P.R. China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, P.R. China
| | - Jingjing Guan
- Department of Orthopedics, First Affiliated Hospital of Bengbu Medical College, Bengbu, P.R. China
| | - Panpan Xu
- Department of Orthopedics, First Affiliated Hospital of Bengbu Medical College, Bengbu, P.R. China
| | - Jingwen Zhao
- Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
| | - Changchun Zhang
- Department of Orthopedics, First Affiliated Hospital of Bengbu Medical College, Bengbu, P.R. China
| | - Bin Zhang
- Department of Orthopedics, First Affiliated Hospital of Bengbu Medical College, Bengbu, P.R. China
| | - Yingji Mao
- Department of Orthopedics, First Affiliated Hospital of Bengbu Medical College, Bengbu, P.R. China
- School of Life Science, Bengbu Medical College, Bengbu, P.R. China
| | - Wenguo Cui
- Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
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25
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Ashammakhi N, Kim HJ, Ehsanipour A, Bierman RD, Kaarela O, Xue C, Khademhosseini A, Seidlits SK. Regenerative Therapies for Spinal Cord Injury. TISSUE ENGINEERING PART B-REVIEWS 2019; 25:471-491. [PMID: 31452463 DOI: 10.1089/ten.teb.2019.0182] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Spinal cord injury (SCI) is a serious problem that primarily affects younger and middle-aged adults at its onset. To date, no effective regenerative treatment has been developed. Over the last decade, researchers have made significant advances in stem cell technology, biomaterials, nanotechnology, and immune engineering, which may be applied as regenerative therapies for the spinal cord. Although the results of clinical trials using specific cell-based therapies have proven safe, their efficacy has not yet been demonstrated. The pathophysiology of SCI is multifaceted, complex and yet to be fully understood. Thus, combinatorial therapies that simultaneously leverage multiple approaches will likely be required to achieve satisfactory outcomes. Although combinations of biomaterials with pharmacologic agents or cells have been explored, few studies have combined these modalities in a systematic way. For most strategies, clinical translation will be facilitated by the use of minimally invasive therapies, which are the focus of this review. In addition, this review discusses previously explored therapies designed to promote neuroregeneration and neuroprotection after SCI, while highlighting present challenges and future directions. Impact Statement To date there are no effective treatments that can regenerate the spinal cord after injury. Although there have been significant preclinical advances in bioengineering and regenerative medicine over the last decade, these have not translated into effective clinical therapies for spinal cord injury. This review focuses on minimally invasive therapies, providing extensive background as well as updates on recent technological developments and current clinical trials. This review is a comprehensive resource for researchers working towards regenerative therapies for spinal cord injury that will help guide future innovation.
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Affiliation(s)
- Nureddin Ashammakhi
- Division of Plastic Surgery, Department of Surgery, Oulu University, Oulu, Finland.,Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California
| | - Han-Jun Kim
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California
| | | | | | - Outi Kaarela
- Division of Plastic Surgery, Department of Surgery, Oulu University, Oulu, Finland
| | - Chengbin Xue
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, P.R. China.,Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Research Center of Clinical Medicine, Affiliated Hospital of Nantong University, Nantong University, Nantong, P.R. China
| | - Ali Khademhosseini
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California.,Center of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Chemical and Biological Engineering, University of California, Los Angeles, California
| | - Stephanie K Seidlits
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, California.,Broad Stem Cell Research Center, University of California, Los Angeles, Los Angeles, California.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California
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26
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Wei Z, Volkova E, Blatchley MR, Gerecht S. Hydrogel vehicles for sequential delivery of protein drugs to promote vascular regeneration. Adv Drug Deliv Rev 2019; 149-150:95-106. [PMID: 31421149 PMCID: PMC6889011 DOI: 10.1016/j.addr.2019.08.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 07/04/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
In recent years, as the mechanisms of vasculogenesis and angiogenesis have been uncovered, the functions of various pro-angiogenic growth factors (GFs) and cytokines have been identified. Therefore, therapeutic angiogenesis, by delivery of GFs, has been sought as a treatment for many vascular diseases. However, direct injection of these protein drugs has proven to have limited clinical success due to their short half-lives and systemic off-target effects. To overcome this, hydrogel carriers have been developed to conjugate single or multiple GFs with controllable, sustained, and localized delivery. However, these attempts have failed to account for the temporal complexity of natural angiogenic pathways, resulting in limited therapeutic effects. Recently, the emerging ideas of optimal sequential delivery of multiple GFs have been suggested to better mimic the biological processes and to enhance therapeutic angiogenesis. Incorporating sequential release into drug delivery platforms will likely promote the formation of neovasculature and generate vast therapeutic potential.
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Affiliation(s)
- Zhao Wei
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology Physical-Sciences Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Eugenia Volkova
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology Physical-Sciences Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Michael R Blatchley
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology Physical-Sciences Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sharon Gerecht
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology Physical-Sciences Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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27
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Saez DM, Sasaki RT, Martins DDO, Chacur M, Kerkis I, da Silva MCP. Rat Facial Nerve Regeneration with Human Immature Dental Pulp Stem Cells. Cell Transplant 2019; 28:1573-1584. [PMID: 31462071 PMCID: PMC6923557 DOI: 10.1177/0963689719854446] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Facial paralysis can result in severe implications for the patients. However, stem cell
biology has become an important field in regenerative medicine since the discovery and
characterization of mesenchymal stem cells. Our aim was to evaluate the regeneration after
facial nerve crush injury and application of human immature dental pulp stem cells
(iDPSC). For this study 70 Wistar rats underwent a unilateral facial nerve crush injury
and were divided into two groups: Group I (GI): Crushed; Group II (GII): Crushed and
iDPSC, and distributed into study periods of 3, 7, 14, 21, and 42 postoperative days.
Facial nerve regeneration was analyzed via functional recovery of whisker movement,
histomorphometric analysis, and immunoblotting assay. The results show that GII had
complete functional recovery at 14 days, while GI recovered after 42 days. Also, regarding
the facial nerve trunk, GII presented histological improvement, evidencing better axonal
and structural organization of the myelin sheath, and exhibited statistically higher
values for the outer and inner perimeters and g-ratio. Nevertheless, GI exhibited
statistically higher values for the thickness of myelin sheath. In the buccal branch, no
differences were observed for all parameters between groups. At 42 days, both groups GI
and GII were close to the levels observed for the control group. Concerning nerve growth
factor expression, GII exhibited statistically greater values (p <
0.05) compared with the control group at 7 days. In summary, a single injection of human
iDPSC promoted a positive effect on regeneration of the facial nerve trunk after 14 days
and provided an alternative to support regeneration following peripheral nerve injury.
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Affiliation(s)
- Daniel Martinez Saez
- Department of Morphology and Genetics, Universidade Federal de São Paulo,
São Paulo, Brazil
- Daniel Martinez Saez, Department of Morphology and
Genetics, Universidade Federal de São Paulo, Rua Botucatu, 740 - Edifício
Leitão da Cunha, Vila Clementino, São Paulo 04023, Brazil.
| | - Robson Tetsuo Sasaki
- Department of Morphology and Genetics, Universidade Federal de São Paulo,
São Paulo, Brazil
| | | | - Marucia Chacur
- Departament of Anatomy, Institute of Biomedical Sciences – Universidade de
São Paulo, São Paulo, Brazil
| | - Irina Kerkis
- Department of Genetics, Instituto Butantan, São Paulo, Brazil
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28
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Xu AK, Gong Z, He YZ, Xia KS, Tao HM. Comprehensive therapeutics targeting the corticospinal tract following spinal cord injury. J Zhejiang Univ Sci B 2019; 20:205-218. [PMID: 30829009 DOI: 10.1631/jzus.b1800280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Spinal cord injury (SCI), which is much in the public eye, is still a refractory disease compromising the well-being of both patients and society. In spite of there being many methods dealing with the lesion, there is still a deficiency in comprehensive strategies covering all facets of this damage. Further, we should also mention the structure called the corticospinal tract (CST) which plays a crucial role in the motor responses of organisms, and it will be the focal point of our attention. In this review, we discuss a variety of strategies targeting different dimensions following SCI and some treatments that are especially efficacious to the CST are emphasized. Over recent decades, researchers have developed many effective tactics involving five approaches: (1) tackle more extensive regions; (2) provide a regenerative microenvironment; (3) provide a glial microenvironment; (4) transplantation; and (5) other auxiliary methods, for instance, rehabilitation training and electrical stimulation. We review the basic knowledge on this disease and correlative treatments. In addition, some well-formulated perspectives and hypotheses have been delineated. We emphasize that such a multifaceted problem needs combinatorial approaches, and we analyze some discrepancies in past studies. Finally, for the future, we present numerous brand-new latent tactics which have great promise for curbing SCI.
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Affiliation(s)
- An-Kai Xu
- Department of Orthopedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.,Orthopedics Research Institute of Zhejiang University, Hangzhou 310009, China
| | - Zhe Gong
- Department of Orthopedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.,Orthopedics Research Institute of Zhejiang University, Hangzhou 310009, China
| | - Yu-Zhe He
- Department of Orthopedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.,Orthopedics Research Institute of Zhejiang University, Hangzhou 310009, China
| | - Kai-Shun Xia
- Department of Orthopedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.,Orthopedics Research Institute of Zhejiang University, Hangzhou 310009, China
| | - Hui-Min Tao
- Department of Orthopedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.,Orthopedics Research Institute of Zhejiang University, Hangzhou 310009, China
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29
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Houlton J, Abumaria N, Hinkley SFR, Clarkson AN. Therapeutic Potential of Neurotrophins for Repair After Brain Injury: A Helping Hand From Biomaterials. Front Neurosci 2019; 13:790. [PMID: 31427916 PMCID: PMC6688532 DOI: 10.3389/fnins.2019.00790] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/15/2019] [Indexed: 12/17/2022] Open
Abstract
Stroke remains the leading cause of long-term disability with limited options available to aid in recovery. Significant effort has been made to try and minimize neuronal damage following stroke with use of neuroprotective agents, however, these treatments have yet to show clinical efficacy. Regenerative interventions have since become of huge interest as they provide the potential to restore damaged neural tissue without being limited by a narrow therapeutic window. Neurotrophins, such as brain-derived neurotrophic factor (BDNF), and their high affinity receptors are actively produced throughout the brain and are involved in regulating neuronal activity and normal day-to-day function. Furthermore, neurotrophins are known to play a significant role in both protection and recovery of function following neurodegenerative diseases such as stroke and traumatic brain injury (TBI). Unfortunately, exogenous administration of these neurotrophins is limited by a lack of blood-brain-barrier (BBB) permeability, poor half-life, and rapid degradation. Therefore, we have focused this review on approaches that provide a direct and sustained neurotrophic support using pharmacological therapies and mimetics, physical activity, and potential drug delivery systems, including discussion around advantages and limitations for use of each of these systems. Finally, we discuss future directions of biomaterial drug-delivery systems, including the incorporation of heparan sulfate (HS) in conjunction with neurotrophin-based interventions.
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Affiliation(s)
- Josh Houlton
- Brain Health Research Centre, Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Nashat Abumaria
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institute of Brain Science, Fudan University, Shanghai, China
- Department of Laboratory Animal Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Simon F. R. Hinkley
- The Ferrier Research Institute, Victoria University of Wellington, Petone, New Zealand
| | - Andrew N. Clarkson
- Brain Health Research Centre, Department of Anatomy, University of Otago, Dunedin, New Zealand
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30
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George J, Hsu CC, Nguyen LTB, Ye H, Cui Z. Neural tissue engineering with structured hydrogels in CNS models and therapies. Biotechnol Adv 2019; 42:107370. [PMID: 30902729 DOI: 10.1016/j.biotechadv.2019.03.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 02/25/2019] [Accepted: 03/11/2019] [Indexed: 01/27/2023]
Abstract
The development of techniques to create and use multiphase microstructured hydrogels (granular hydrogels or microgels) has enabled the generation of cultures with more biologically relevant architecture and use of structured hydrogels is especially pertinent to the development of new types of central nervous system (CNS) culture models and therapies. We review material choice and the customisation of hydrogel structure, as well as the use of hydrogels in developmental models. Combining the use of structured hydrogel techniques with developmentally relevant tissue culture approaches will enable the generation of more relevant models and treatments to repair damaged CNS tissue architecture.
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Affiliation(s)
- Julian George
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Chia-Chen Hsu
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Linh Thuy Ba Nguyen
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Hua Ye
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom.
| | - Zhanfeng Cui
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom.
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31
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Stem cell paracrine effect and delivery strategies for spinal cord injury regeneration. J Control Release 2019; 300:141-153. [PMID: 30851286 DOI: 10.1016/j.jconrel.2019.02.038] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 12/29/2022]
Abstract
Spinal cord injury (SCI) is a complicated neuropathological condition that results in functional dysfunction and paralysis. Various treatments have been proposed including drugs, biological factors and cells administered in several ways. Stem cell therapy offers a potentially revolutionary mode to repair the damaged spinal cord after injury. Initially, stem cells were considered promising for replacing cells and tissue lost after SCI. Many studies looked at their differentiation to replace neuronal and glial cells for a better functional outcome. However, it is becoming clear that different functional improvements recognized to stem cells are due to biomolecular activities by the transplanted stem cells rather than cell replacement. This review aimed to discuss the paracrine mechanisms for tissue repair and regeneration after stem cell transplantation in SCI. It focuses on stem cell factor production, effect in tissue restoration, and novel delivery strategies to use them for SCI therapy.
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32
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Oligodendrogliogenesis and Axon Remyelination after Traumatic Spinal Cord Injuries in Animal Studies: A Systematic Review. Neuroscience 2019; 402:37-50. [PMID: 30685542 DOI: 10.1016/j.neuroscience.2019.01.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/12/2019] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
Abstract
Extensive oligodendrocyte death after acute traumatic spinal cord injuries (TSCI) leads to axon demyelination and subsequently may leave axons vulnerable to degeneration. Despite the present evidence showing spontaneous remyelination after TSCI the cellular origin of new myelin and the time course of the axon ensheathment/remyelination remained controversial issue. In this systematic review the trend of oligodendrocyte death after injury as well as the extent and the cellular origin of oligodendrogliogenesis were comprehensively evaluated. The study design was based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-guided systematic review. PubMed and EMBASE were searched with no temporal or linguistic restrictions. Also, hand-search was performed in the bibliographies of relevant articles. Non-interventional animal studies discussing different types of myelinating cells including oligodendrocytes, Schwann cells and oligodendrocyte progenitor cells (OPCs) were evaluated. The extent of oligodendrocyte death, oligodendrocyte differentiation and remyelination were the pathophysiological outcome measures. We found 12,359 studies, 34 of which met the inclusion criteria. The cumulative evidence shows extensive oligodendrocytes cell death during the first week post-injury (pi). OPCs and peripheral invading Schwann cells are the dominant cells contributing in myelin formation. The maximum OPC proliferation was observed at around 2 weeks pi and oligodendrogliogenesis continues at later stages until the number of oligodendrocytes return to normal tissue by one month pi. Taken together, the evidence in animals reveals the potential role for endogenous myelinating cells in the axon ensheathment/remyelination after TSCI and this can be the target of pharmacotherapy to induce oligodendrocyte differentiation and myelin formation post-injury.
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33
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Pertici V, Pin-Barre C, Rivera C, Pellegrino C, Laurin J, Gigmes D, Trimaille T. Degradable and Injectable Hydrogel for Drug Delivery in Soft Tissues. Biomacromolecules 2018; 20:149-163. [PMID: 30376309 DOI: 10.1021/acs.biomac.8b01242] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Injectable hydrogels are promising platforms for tissue engineering and local drug delivery as they allow minimal invasiveness. We have here developed an injectable and biodegradable hydrogel based on an amphiphilic PNIPAAm- b-PLA- b-PEG- b-PLA- b-PNIPAAm pentablock copolymer synthesized by ring-opening polymerization/nitroxide-mediated polymerization (ROP/NMP) combination. The hydrogel formation at around 30 °C was demonstrated to be mediated by intermicellar bridging through the PEG central block. Such a result was particularly highlighted by the inability of a PEG- b-PLA- b-PNIPAAm triblock analog of the same composition to gelify. The hydrogels degraded through hydrolysis of the PLA esters until complete mass loss due to the diffusion of the recovered PEG and PNIPAAm/micelle based residues in the solution. Interestingly, hydrophobic molecules such as riluzole (neuroprotective drug) or cyanine 5.5 (imaging probe) could be easily loaded in the hydrogels' micelle cores by mixing them with the copolymer solution at room temperature. Drug release was correlated to polymer mass loss. The hydrogel was shown to be cytocompatible (neuronal cells, in vitro) and injectable through a small-gauge needle (in vivo in rats). Thus, this hydrogel platform displays highly attractive features for use in brain/soft tissue engineering as well as in drug delivery.
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Affiliation(s)
- Vincent Pertici
- Aix Marseille Université, CNRS, ICR , F-13397 Marseille , France
| | | | - Claudio Rivera
- Aix Marseille Université, INSERM, INMED , F-13397 Marseille , France
| | | | - Jérôme Laurin
- Aix Marseille Université, CNRS, ISM , F-13397 Marseille , France
| | - Didier Gigmes
- Aix Marseille Université, CNRS, ICR , F-13397 Marseille , France
| | - Thomas Trimaille
- Aix Marseille Université, CNRS, ICR , F-13397 Marseille , France
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34
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Tom B, Witko J, Lemay M, Singh A. Effects of bioengineered scaffold loaded with neurotrophins and locomotor training in restoring H-reflex responses after spinal cord injury. Exp Brain Res 2018; 236:3077-3084. [PMID: 30132039 DOI: 10.1007/s00221-018-5344-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 07/24/2018] [Indexed: 02/02/2023]
Abstract
The combinational effects of a bioengineered scaffold loaded with neurotrophins and rehabilitation training on spasticity observed after spinal cord injury (SCI) has not been studied. We used an animal model of moderate contusion injury at T9/T10 that received bioengineered scaffold poly N-isopropylacrylamide-g-poly ethylene glycol (PNIPAAm-g-PEG) loaded with BDNF/NT3 followed by body weight supported treadmill training (BWSTT) and assessed the efficacy of the combinational bioengineered approaches in treating spasticity. Five animal groups were included: Group 1: Sham, Group 2: Injury (SCI), Group 3: SCI + BWSTT (BWSTT), Group 4: SCI + PNIPAAm-g-PEG loaded with BDNF/NT3 (Transplant), and Group 5: SCI + PNIPAAm-g-PEG loaded with BDNF/NT3 + BWSTT (Combinational). Results indicate no significant changes in the BBB scores of animals among various groups, however, a significant restoration in the rate depression property of H-reflex was observed in both BWSTT and Combinational animals. Transplant group reported no improvement in the rate depression property of H-reflex and were similar to SCI only group. Histological findings report restoration of the chloride cotransporter (KCC2) labeling in both BWSTT and Combinational animals and down-regulation of KCC2 in both SCI and Transplant only animals. Findings from this study confirm that rehabilitation training is critical in restoring H-reflex responses and transplantation therapies alone cannot restore these responses after SCI. Also, although no significant difference was observed between the BWSTT and Combinational animals, comparable improvements in the two groups does open new pathways to exploring unique tissue-engineering approaches with promising clinical application for individuals with SCI.
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Affiliation(s)
- Babitha Tom
- Biomedical Engineering, Widener University, One University Place, Chester, PA, USA
| | - Jaclyn Witko
- Mechanical Engineering, Rowan University, Glassboro, NJ, USA
| | - Michel Lemay
- Bioengineering, College of Engineering, Temple University, 1947 North 12th St., Philadelphia, PA, USA
| | - Anita Singh
- Biomedical Engineering, Widener University, One University Place, Chester, PA, USA.
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35
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Shin JE, Jung K, Kim M, Hwang K, Lee H, Kim IS, Lee BH, Lee IS, Park KI. Brain and spinal cord injury repair by implantation of human neural progenitor cells seeded onto polymer scaffolds. Exp Mol Med 2018; 50:1-18. [PMID: 29674624 PMCID: PMC5938022 DOI: 10.1038/s12276-018-0054-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 12/18/2017] [Accepted: 12/21/2017] [Indexed: 12/22/2022] Open
Abstract
Hypoxic-ischemic (HI) brain injury and spinal cord injury (SCI) lead to extensive tissue loss and axonal degeneration. The combined application of the polymer scaffold and neural progenitor cells (NPCs) has been reported to enhance neural repair, protection and regeneration through multiple modes of action following neural injury. This study investigated the reparative ability and therapeutic potentials of biological bridges composed of human fetal brain-derived NPCs seeded upon poly(glycolic acid)-based scaffold implanted into the infarction cavity of a neonatal HI brain injury or the hemisection cavity in an adult SCI. Implantation of human NPC (hNPC)–scaffold complex reduced the lesion volume, induced survival, engraftment, and differentiation of grafted cells, increased neovascularization, inhibited glial scar formation, altered the microglial/macrophage response, promoted neurite outgrowth and axonal extension within the lesion site, and facilitated the connection of damaged neural circuits. Tract tracing demonstrated that hNPC–scaffold grafts appear to reform the connections between neurons and their targets in both cerebral hemispheres in HI brain injury and protect some injured corticospinal fibers in SCI. Finally, the hNPC–scaffold complex grafts significantly improved motosensory function and attenuated neuropathic pain over that of the controls. These findings suggest that, with further investigation, this optimized multidisciplinary approach of combining hNPCs with biomaterial scaffolds provides a more versatile treatment for brain injury and SCI. Biodegradable scaffolds seeded with human fetal brain cells can help repair neurological injuries in rodents. A team led by Kook In Park and Il-Shin Lee from the Yonsei University College of Medicine in Seoul, South Korea, created a mesh of plastic fibers that they bathed in neural progenitor cells. Over the course of several days, these cells differentiated into different types of brain cells, including neurons and glia. The researchers implanted these cell-scaffold complexes into the sites of injury in two rodent models: newborn mice with oxygen deprivation to the brain, and adult rats with severed spinal cords. In both cases, the treatment helped the injured tissues heal and improved the neurological or motor function of the animals. The authors suggest these tissue-engineered structures could also help people with brain or spine injuries.
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Affiliation(s)
- Jeong Eun Shin
- Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Kwangsoo Jung
- Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Miri Kim
- Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Kyujin Hwang
- Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Haejin Lee
- Yonsei Biomedical Research Institute, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Il-Sun Kim
- Yonsei Biomedical Research Institute, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Bae Hwan Lee
- Department of Physiology, Brain Research Institute, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Il-Shin Lee
- Yonsei Biomedical Research Institute, Yonsei University College of Medicine, Seoul, 03722, Korea.
| | - Kook In Park
- Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, 03722, Korea. .,Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Korea. .,Yonsei Biomedical Research Institute, Yonsei University College of Medicine, Seoul, 03722, Korea.
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36
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Koss KM, Churchward MA, Jeffery AF, Mushahwar VK, Elias AL, Todd KG. Improved 3D Hydrogel Cultures of Primary Glial Cells for In Vitro Modelling of Neuroinflammation. J Vis Exp 2017. [PMID: 29286415 DOI: 10.3791/56615] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the central nervous system, numerous acute injuries and neurodegenerative disorders, as well as implanted devices or biomaterials engineered to enhance function result in the same outcome: excess inflammation leads to gliosis, cytotoxicity, and/or formation of a glial scar that collectively exacerbate injury or prevent healthy recovery. With the intent of creating a system to model glial scar formation and study inflammatory processes, we have generated a 3D cell scaffold capable of housing primary cultured glial cells: microglia that regulate the foreign body response and initiate the inflammatory event, astrocytes that respond to form a fibrous scar, and oligodendrocytes that are typically vulnerable to inflammatory injury. The present work provides a detailed step-by-step method for the fabrication, culture, and microscopic characterization of a hyaluronic acid-based 3D hydrogel scaffold with encapsulated rat brain-derived glial cells. Further, protocols for characterization of cell encapsulation and the hydrogel scaffold by confocal immunofluorescence and scanning electron microscopy are demonstrated, as well as the capacity to modify the scaffold with bioactive substrates, with incorporation of a commercial basal lamina mixture to improved cell integration.
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Affiliation(s)
- Kyle M Koss
- Department of Psychiatry, University of Alberta; Alberta Innovates-Health Solutions Interdisciplinary Team in Smart Neural Prostheses (Project SMART), University of Alberta
| | - Matthew A Churchward
- Department of Psychiatry, University of Alberta; Alberta Innovates-Health Solutions Interdisciplinary Team in Smart Neural Prostheses (Project SMART), University of Alberta
| | - Andrea F Jeffery
- Department of Psychiatry, University of Alberta; Department of Chemical and Materials Engineering, University of Alberta
| | - Vivian K Mushahwar
- Department of Psychiatry, University of Alberta; Alberta Innovates-Health Solutions Interdisciplinary Team in Smart Neural Prostheses (Project SMART), University of Alberta; Division of Physical Medicine and Rehabilitation, University of Alberta
| | - Anastasia L Elias
- Department of Chemical and Materials Engineering, University of Alberta
| | - Kathryn G Todd
- Department of Psychiatry, University of Alberta; Alberta Innovates-Health Solutions Interdisciplinary Team in Smart Neural Prostheses (Project SMART), University of Alberta; Centre for Neuroscience, University of Alberta;
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37
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Kanekiyo K, Wakabayashi T, Nakano N, Yamada Y, Tamachi M, Suzuki Y, Fukushima M, Saito F, Abe S, Tsukagoshi C, Miyamoto C, Ide C. Effects of Intrathecal Injection of the Conditioned Medium from Bone Marrow Stromal Cells on Spinal Cord Injury in Rats. J Neurotrauma 2017; 35:521-532. [PMID: 29054133 DOI: 10.1089/neu.2017.5201] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Bone marrow stromal cells (BMSCs) have been studied for the treatment of spinal cord injury (SCI). In previous studies, we showed that the transplantation of BMSCs, even though they disappeared from the host spinal cord within 1-3 weeks after transplantation, improved locomotor behaviors and promoted axonal regeneration. This result led to the hypothesis that BMSCs might release some neurotrophic factors effective for the treatment of SCI. The present study examined this by injecting the conditioned medium (CM) of BMSCs to treat SCI in rats. The spinal cord was contusion-injured, followed immediately by continuous injection for 2 weeks of the CM of BMSCs through the cerebrospinal fluid via the 4th ventricle using an Alzet osmotic pump. Locomotor behaviors evaluated by the Basso-Beattie-Bresnahan score were markedly improved in the CM-injection group, compared with the control group, at 1 to 4 weeks post-injection. The contusion-injured site of the spinal cord was identified as an astrocyte-devoid area, which contained no astrocytes but was filled with collagen matrices and empty cavities of various sizes. Collagen matrices contained type I collagen and laminin. Numerous axons extended through the collagen matrices of the astrocyte-devoid area. Axons were surrounded by Schwann cells, exhibiting the same morphological characteristics as peripheral nerve fibers. The density of axons extending through the astrocyte-devoid area was higher in the CM-injection group, compared with the control group. CM injection had beneficial effects on locomotor improvements and tissue repair, including axonal regeneration, meaning that the BMSC-CM stimulated the intrinsic ability of the spinal cord to regenerate. Activation of the intrinsic ability of the spinal cord to regenerate by the injection of neurotrophic factors such as BMSC-CM is considered to be a safe and preferable method for the clinical treatment of SCI.
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Affiliation(s)
- Kenji Kanekiyo
- 1 Central Biomedical Laboratory, Aino University School of Health Science , Osaka, Japan
| | - Tamami Wakabayashi
- 1 Central Biomedical Laboratory, Aino University School of Health Science , Osaka, Japan
| | - Norihiko Nakano
- 1 Central Biomedical Laboratory, Aino University School of Health Science , Osaka, Japan
| | - Yoshihiro Yamada
- 2 Department of Physical Therapy, Aino University School of Health Science , Osaka, Japan
| | - Masahiro Tamachi
- 2 Department of Physical Therapy, Aino University School of Health Science , Osaka, Japan
| | - Yoshihisa Suzuki
- 3 Department of Plastic and Reconstructive Surgery, Tazuke Medical Research Institute , Kitano Hospital, Osaka, Japan
| | - Masatoshi Fukushima
- 4 Translational Research Informatics Center , Foundation for Biomedical Research and Innovation, Kobe, Japan
| | - Fukuki Saito
- 5 Emergency and Clinical Care Center, Kansai Medical University , Osaka, Japan
| | - Seiya Abe
- 6 Department of Occupational Therapy, Aino University School of Health Science , Osaka, Japan
| | - Chihiro Tsukagoshi
- 6 Department of Occupational Therapy, Aino University School of Health Science , Osaka, Japan
| | - Chimi Miyamoto
- 6 Department of Occupational Therapy, Aino University School of Health Science , Osaka, Japan
| | - Chizuka Ide
- 1 Central Biomedical Laboratory, Aino University School of Health Science , Osaka, Japan
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38
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Barriga-Rivera A, Bareket L, Goding J, Aregueta-Robles UA, Suaning GJ. Visual Prosthesis: Interfacing Stimulating Electrodes with Retinal Neurons to Restore Vision. Front Neurosci 2017; 11:620. [PMID: 29184478 PMCID: PMC5694472 DOI: 10.3389/fnins.2017.00620] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/23/2017] [Indexed: 01/06/2023] Open
Abstract
The bypassing of degenerated photoreceptors using retinal neurostimulators is helping the blind to recover functional vision. Researchers are investigating new ways to improve visual percepts elicited by these means as the vision produced by these early devices remain rudimentary. However, several factors are hampering the progression of bionic technologies: the charge injection limits of metallic electrodes, the mechanical mismatch between excitable tissue and the stimulating elements, neural and electric crosstalk, the physical size of the implanted devices, and the inability to selectively activate different types of retinal neurons. Electrochemical and mechanical limitations are being addressed by the application of electromaterials such as conducting polymers, carbon nanotubes and nanocrystalline diamonds, among other biomaterials, to electrical neuromodulation. In addition, the use of synthetic hydrogels and cell-laden biomaterials is promising better interfaces, as it opens a door to establishing synaptic connections between the electrode material and the excitable cells. Finally, new electrostimulation approaches relying on the use of high-frequency stimulation and field overlapping techniques are being developed to better replicate the neural code of the retina. All these elements combined will bring bionic vision beyond its present state and into the realm of a viable, mainstream therapy for vision loss.
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Affiliation(s)
- Alejandro Barriga-Rivera
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
- Division of Neuroscience, University Pablo de Olavide, Sevilla, Spain
| | - Lilach Bareket
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
| | - Josef Goding
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | | | - Gregg J. Suaning
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
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Abstract
Hydrogels mimic many of the physical properties of soft tissue and are widely used biomaterials for tissue engineering and regenerative medicine. Synthetic hydrogels have been developed to recapitulate many of the healthy and diseased states of native tissues and can be used as a cell scaffold to study the effect of matricellular interactions in vitro. However, these matrices often fail to capture the dynamic and heterogenous nature of the in vivo environment, which varies spatially and during events such as development and disease. To address this deficiency, a variety of manufacturing and processing techniques are being adapted to the biomaterials setting. Among these, photochemistry is particularly well suited because these reactions can be performed in precise three-dimensional space and at specific moments in time. This spatiotemporal control over chemical reactions can also be performed over a range of cell- and tissue-relevant length scales with reactions that proceed efficiently and harmlessly at ambient conditions. This review will focus on the use of photochemical reactions to create dynamic hydrogel environments, and how these dynamic environments are being used to investigate and direct cell behavior.
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Affiliation(s)
- Tobin E Brown
- Department of Chemical and Biological Engineering, University of Colorado Boulder, USA.
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40
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Hong LTA, Kim YM, Park HH, Hwang DH, Cui Y, Lee EM, Yahn S, Lee JK, Song SC, Kim BG. An injectable hydrogel enhances tissue repair after spinal cord injury by promoting extracellular matrix remodeling. Nat Commun 2017; 8:533. [PMID: 28912446 PMCID: PMC5599609 DOI: 10.1038/s41467-017-00583-8] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 07/10/2017] [Indexed: 11/22/2022] Open
Abstract
The cystic cavity that develops following injuries to brain or spinal cord is a major obstacle for tissue repair in central nervous system (CNS). Here we report that injection of imidazole-poly(organophosphazenes) (I-5), a hydrogel with thermosensitive sol–gel transition behavior, almost completely eliminates cystic cavities in a clinically relevant rat spinal cord injury model. Cystic cavities are bridged by fibronectin-rich extracellular matrix. The fibrotic extracellular matrix remodeling is mediated by matrix metalloproteinase-9 expressed in macrophages within the fibrotic extracellular matrix. A poly(organophosphazenes) hydrogel lacking the imidazole moiety, which physically interacts with macrophages via histamine receptors, exhibits substantially diminished bridging effects. I-5 injection improves coordinated locomotion, and this functional recovery is accompanied by preservation of myelinated white matter and motor neurons and an increase in axonal reinnervation of the lumbar motor neurons. Our study demonstrates that dynamic interactions between inflammatory cells and injectable biomaterials can induce beneficial extracellular matrix remodeling to stimulate tissue repair following CNS injuries. The cystic cavity that develops following injuries to brain or spinal cord is a major obstacle. Here the authors show an injection of imidazole poly(organophosphazenes), a hydrogel with thermosensitive sol–gel transition behavior, almost completely eliminates cystic cavities in a clinically relevant rat spinal cord injury model.
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Affiliation(s)
- Le Thi Anh Hong
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University Graduate School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea
| | - Young-Min Kim
- Center for Biomaterials, Korea Institute of Science and Technology (KIST), 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Hee Hwan Park
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University Graduate School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea
| | - Dong Hoon Hwang
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea
| | - Yuexian Cui
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University Graduate School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea
| | - Eun Mi Lee
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea
| | - Stephanie Yahn
- Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami School of Medicine, 1095 NW 14th Terrace (R-48), Miami, FL, 33136, USA
| | - Jae K Lee
- Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami School of Medicine, 1095 NW 14th Terrace (R-48), Miami, FL, 33136, USA
| | - Soo-Chang Song
- Center for Biomaterials, Korea Institute of Science and Technology (KIST), 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul, 02792, Republic of Korea. .,Department of Biomolecular Science, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea.
| | - Byung Gon Kim
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea. .,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University Graduate School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea. .,Department of Neurology, Ajou University School of Medicine, 164, Worldcup-ro, Yeongtong-gu, Suwon, 16499, Republic of Korea.
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Führmann T, Anandakumaran PN, Shoichet MS. Combinatorial Therapies After Spinal Cord Injury: How Can Biomaterials Help? Adv Healthc Mater 2017; 6. [PMID: 28247563 DOI: 10.1002/adhm.201601130] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/05/2016] [Indexed: 12/31/2022]
Abstract
Traumatic spinal cord injury (SCI) results in an immediate loss of motor and sensory function below the injury site and is associated with a poor prognosis. The inhibitory environment that develops in response to the injury is mainly due to local expression of inhibitory factors, scarring and the formation of cystic cavitations, all of which limit the regenerative capacity of endogenous or transplanted cells. Strategies that demonstrate promising results induce a change in the microenvironment at- and around the lesion site to promote endogenous cell repair, including axonal regeneration or the integration of transplanted cells. To date, many of these strategies target only a single aspect of SCI; however, the multifaceted nature of SCI suggests that combinatorial strategies will likely be more effective. Biomaterials are a key component of combinatorial strategies, as they have the potential to deliver drugs locally over a prolonged period of time and aid in cell survival, integration and differentiation. Here we summarize the advantages and limitations of widely used strategies to promote recovery after injury and highlight recent research where biomaterials aided combinatorial strategies to overcome some of the barriers of spinal cord regeneration.
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Affiliation(s)
- Tobias Führmann
- The Donnelly Centre for Cellular and Biomolecular Research; 160 College Street, Room 514 Toronto ON M5S 3E1 Canada
- Department of Chemical Engineering and Applied Chemistry; 200 College Street Toronto ON M5S 3E5 Canada
| | - Priya N. Anandakumaran
- The Donnelly Centre for Cellular and Biomolecular Research; 160 College Street, Room 514 Toronto ON M5S 3E1 Canada
- Institute of Biomaterials and Biomedical Engineering; 164 College Street Toronto ON M5S 3G9 Canada
| | - Molly S. Shoichet
- The Donnelly Centre for Cellular and Biomolecular Research; 160 College Street, Room 514 Toronto ON M5S 3E1 Canada
- Department of Chemical Engineering and Applied Chemistry; 200 College Street Toronto ON M5S 3E5 Canada
- Institute of Biomaterials and Biomedical Engineering; 164 College Street Toronto ON M5S 3G9 Canada
- Department of Chemistry; University of Toronto; 80 St George St Toronto ON M5S 3H6 Canada
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42
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Nguyen LH, Gao M, Lin J, Wu W, Wang J, Chew SY. Three-dimensional aligned nanofibers-hydrogel scaffold for controlled non-viral drug/gene delivery to direct axon regeneration in spinal cord injury treatment. Sci Rep 2017; 7:42212. [PMID: 28169354 PMCID: PMC5294639 DOI: 10.1038/srep42212] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/06/2017] [Indexed: 01/07/2023] Open
Abstract
Spinal cord injuries (SCI) often lead to persistent neurological dysfunction due to failure in axon regeneration. Unfortunately, currently established treatments, such as direct drug administration, do not effectively treat SCI due to rapid drug clearance from our bodies. Here, we introduce a three-dimensional aligned nanofibers-hydrogel scaffold as a bio-functionalized platform to provide sustained non-viral delivery of proteins and nucleic acid therapeutics (small non-coding RNAs), along with synergistic contact guidance for nerve injury treatment. A hemi-incision model at cervical level 5 in the rat spinal cord was chosen to evaluate the efficacy of this scaffold design. Specifically, aligned axon regeneration was observed as early as one week post-injury. In addition, no excessive inflammatory response and scar tissue formation was triggered. Taken together, our results demonstrate the potential of our scaffold for neural tissue engineering applications.
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Affiliation(s)
- Lan Huong Nguyen
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Mingyong Gao
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Department of Spine Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Junquan Lin
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Wutian Wu
- School of Biomedical Sciences, The University of Hong Kong Li Ka Shing Faculty of Medicine, Pokfulam, Hong Kong SAR, China
- Research Center of Reproduction, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, PR China
| | - Jun Wang
- The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science & Technology of China, Hefei, Anhui 230027, PR China
| | - Sing Yian Chew
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
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43
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Guven MN, Seckin Altuncu M, Demir Duman F, Eren TN, Yagci Acar H, Avci D. Bisphosphonate-functionalized poly(β-amino ester) network polymers. J Biomed Mater Res A 2017; 105:1412-1421. [PMID: 28165665 DOI: 10.1002/jbm.a.36026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 01/20/2023]
Abstract
Three novel bisphosphonate-functionalized secondary diamines are synthesized and incorporated into poly(β-amino ester)s (PBAEs) to investigate the effects of bisphosphonates on biodegradation and toxicity of PBAE polymer networks. These three novel amines, BPA1, BPA2, and BPA3, were prepared from the reactions of 1,4-butanediamine, 1,6-hexanediamine, or 4,9-dioxa-1,12-dodecanediamine with tetraethyl vinylidene bisphosphonate, respectively. The PBAE macromers were obtained from the aza-Michael addition reaction of these amines to 1,6-hexane diol diacrylate (HDDA) and poly(ethylene glycol) diacrylate (PEGDA, Mn = 575) and photopolymerized to produce biodegradable gels. These gels with different chemistries exhibited similar degradation behavior with mass loss of 53-73% within 24 h, indicating that degradation is mostly governed by the bisphosphonate group. Based on the in vitro cytotoxicity evaluation against NIH 3T3 mouse embryonic fibroblast cells, the degradation products do not exhibit significant toxicity in most cases. It was also shown that PBAE macromers can be used as cross-linkers for the synthesis of 2-hydroxyethyl methacrylate hydrogels, conferring small and customizable degradation rates upon them. The materials reported have potential to be used as nontoxic degradable biomaterials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1412-1421, 2017.
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Affiliation(s)
- Melek Naz Guven
- Department of Chemistry, Bogazici University, 34342 Bebek, Istanbul, Turkey
| | | | - Fatma Demir Duman
- Graduate School of Materials Science and Engineering, Koc University, Sariyer, Istanbul, 34450, Turkey
| | - Tugce Nur Eren
- Department of Chemistry, Bogazici University, 34342 Bebek, Istanbul, Turkey
| | - Havva Yagci Acar
- Graduate School of Materials Science and Engineering, Koc University, Sariyer, Istanbul, 34450, Turkey.,Department of Chemistry, Koc University, Sariyer, Istanbul, 34450, Turkey
| | - Duygu Avci
- Department of Chemistry, Bogazici University, 34342 Bebek, Istanbul, Turkey
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44
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Hodgetts SI, Harvey AR. Neurotrophic Factors Used to Treat Spinal Cord Injury. VITAMINS AND HORMONES 2016; 104:405-457. [PMID: 28215303 DOI: 10.1016/bs.vh.2016.11.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The application of neurotrophic factors as a therapy to improve morphological and behavioral outcomes after experimental spinal cord injury (SCI) has been the focus of many studies. These studies vary markedly in the type of neurotrophic factor that is delivered, the mode of administration, and the location, timing, and duration of the treatment. Generally, the majority of studies have had significant success if neurotrophic factors are applied in or close to the lesion site during the acute or the subacute phase after SCI. Comparatively fewer studies have administered neurotrophic factors in order to directly target the somata of injured neurons. The mode of delivery varies between acute injection of recombinant proteins, subacute or chronic delivery using a variety of strategies including osmotic minipumps, cell-mediated delivery, delivery using polymer release vehicles or supporting bridges of some sort, or the use of gene therapy to modify neurons, glial cells, or precursor/stem cells. In this brief review, we summarize the state of play of many of the therapies using these factors, most of which have been undertaken in rodent models of SCI.
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Affiliation(s)
- S I Hodgetts
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, WA, Australia; Western Australian Neuroscience Research Institute, Perth, WA, Australia.
| | - A R Harvey
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, WA, Australia; Western Australian Neuroscience Research Institute, Perth, WA, Australia
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45
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Cornel Iridoid Glycoside Improves Locomotor Impairment and Decreases Spinal Cord Damage in Rats. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6725381. [PMID: 27990434 PMCID: PMC5136393 DOI: 10.1155/2016/6725381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/06/2016] [Accepted: 10/04/2016] [Indexed: 01/21/2023]
Abstract
Purpose. This study was to investigate the effects of cornel iridoid glycoside (CIG) on spinal cord injury (SCI) in rats. Methods. The thoracic cord (at T9) of rats was injured by clip compression for 30 sec. Locomotor function was assessed using the Basso, Beattie, and Bresnahan (BBB) rating scale. Neuroanatomic stereological parameters as well as Nogo-A, p75 neurotrophin receptor (p75NTR), and ROCKII expression were measured by histological processing, immunohistochemistry, and stereological analyses. The axons passing through the lesion site were detected by BDA tracing. Results. Intragastric administration of CIG (60 and 180 mg/kg) improved the locomotor impairment at 10, 17, 24, and 31 days post-injury (dpi) compared with untreated SCI model rats. CIG treatment decreased the volume of the lesion epicenter (LEp) and increased the volume of spared tissue and the number of surviving neurons in the injured spinal cord at 31 dpi. CIG promoted the growth of BDA-positive axons and their passage through the lesion site and decreased the expression of Nogo-A, p75NTR, and ROCKII both in and around the LEp. Conclusion. CIG improved the locomotor impairment, decreased tissue damage, and downregulated the myelin-associated inhibition signaling pathway in SCI rats. The results suggest that CIG may be beneficial for SCI therapy.
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46
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Differential regenerative ability of sensory and motor neurons. Neurosci Lett 2016; 652:35-40. [PMID: 27818349 DOI: 10.1016/j.neulet.2016.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/24/2016] [Accepted: 11/01/2016] [Indexed: 11/22/2022]
Abstract
After injury, the adult mammalian central nervous system (CNS) lacks long-distance axon regeneration. This review discusses the similarities and differences of sensory and motor neurons, seeking to understand how to achieve functional sensory and motor regeneration. As these two types of neurons respond differently to axotomy, growth environment and treatment, the future challenge will be on how to achieve full recovery in a way that allows regeneration of both types of fibres simultaneously.
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47
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Koss K, Unsworth L. Neural tissue engineering: Bioresponsive nanoscaffolds using engineered self-assembling peptides. Acta Biomater 2016; 44:2-15. [PMID: 27544809 DOI: 10.1016/j.actbio.2016.08.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 07/26/2016] [Accepted: 08/16/2016] [Indexed: 12/25/2022]
Abstract
UNLABELLED Rescuing or repairing neural tissues is of utmost importance to the patient's quality of life after an injury. To remedy this, many novel biomaterials are being developed that are, ideally, non-invasive and directly facilitate neural wound healing. As such, this review surveys the recent approaches and applications of self-assembling peptides and peptide amphiphiles, for building multi-faceted nanoscaffolds for direct application to neural injury. Specifically, methods enabling cellular interactions with the nanoscaffold and controlling the release of bioactive molecules from the nanoscaffold for the express purpose of directing endogenous cells in damaged or diseased neural tissues is presented. An extensive overview of recently derived self-assembling peptide-based materials and their use as neural nanoscaffolds is presented. In addition, an overview of potential bioactive peptides and ligands that could be used to direct behaviour of endogenous cells are categorized with their biological effects. Finally, a number of neurotrophic and anti-inflammatory drugs are described and discussed. Smaller therapeutic molecules are emphasized, as they are thought to be able to have less potential effect on the overall peptide self-assembly mechanism. Options for potential nanoscaffolds and drug delivery systems are suggested. STATEMENT OF SIGNIFICANCE Self-assembling nanoscaffolds have many inherent properties making them amenable to tissue engineering applications: ease of synthesis, ease of customization with bioactive moieties, and amenable for in situ nanoscaffold formation. The combination of the existing knowledge on bioactive motifs for neural engineering and the self-assembling propensity of peptides is discussed in specific reference to neural tissue engineering.
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48
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Khaing ZZ, Ehsanipour A, Hofstetter CP, Seidlits SK. Injectable Hydrogels for Spinal Cord Repair: A Focus on Swelling and Intraspinal Pressure. Cells Tissues Organs 2016; 202:67-84. [DOI: 10.1159/000446697] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2016] [Indexed: 11/19/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating condition that leaves patients with limited motor and sensory function at and below the injury site, with little to no hope of a meaningful recovery. Because of their ability to mimic multiple features of central nervous system (CNS) tissues, injectable hydrogels are being developed that can participate as therapeutic agents in reducing secondary injury and in the regeneration of spinal cord tissue. Injectable biomaterials can provide a supportive substrate for tissue regeneration, deliver therapeutic factors, and regulate local tissue physiology. Recent reports of increasing intraspinal pressure after SCI suggest that this physiological change can contribute to injury expansion, also known as secondary injury. Hydrogels contain high water content similar to native tissue, and many hydrogels absorb water and swell after formation. In the case of injectable hydrogels for the spinal cord, this process often occurs in or around the spinal cord tissue, and thus may affect intraspinal pressure. In the future, predictable swelling properties of hydrogels may be leveraged to control intraspinal pressure after injury. Here, we review the physiology of SCI, with special attention to the current clinical and experimental literature, underscoring the importance of controlling intraspinal pressure after SCI. We then discuss how hydrogel fabrication, injection, and swelling can impact intraspinal pressure in the context of developing injectable biomaterials for SCI treatment.
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49
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Affiliation(s)
- Melinda Fitzgerald
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, Western Australia, Australia
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50
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Russo T, Tunesi M, Giordano C, Gloria A, Ambrosio L. Hydrogels for central nervous system therapeutic strategies. Proc Inst Mech Eng H 2016; 229:905-16. [PMID: 26614804 DOI: 10.1177/0954411915611700] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The central nervous system shows a limited regenerative capacity, and injuries or diseases, such as those in the spinal, brain and retina, are a great problem since current therapies seem to be unable to achieve good results in terms of significant functional recovery. Different promising therapies have been suggested, the aim being to restore at least some of the lost functions. The current review deals with the use of hydrogels in developing advanced devices for central nervous system therapeutic strategies. Several approaches, involving cell-based therapy, delivery of bioactive molecules and nanoparticle-based drug delivery, will be first reviewed. Finally, some examples of injectable hydrogels for the delivery of bioactive molecules in central nervous system will be reported, and the key features as well as the basic principles in designing multifunctional devices will be described.
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Affiliation(s)
- Teresa Russo
- Institute of Polymers, Composites and Biomaterials, National Research Council of Italy, Naples, Italy
| | - Marta Tunesi
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano and Unità di Ricerca Consorzio INSTM, Politecnico di Milano, Milan, Italy
| | - Carmen Giordano
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano and Unità di Ricerca Consorzio INSTM, Politecnico di Milano, Milan, Italy
| | - Antonio Gloria
- Institute of Polymers, Composites and Biomaterials, National Research Council of Italy, Naples, Italy
| | - Luigi Ambrosio
- Institute of Polymers, Composites and Biomaterials, National Research Council of Italy, Naples, Italy
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