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Szałapata K, Pięt M, Kasela M, Grąz M, Kapral-Piotrowska J, Mordzińska-Rak A, Samorek E, Pieniądz P, Polak J, Osińska-Jaroszuk M, Paduch R, Pawlikowska-Pawlęga B, Malm A, Jarosz-Wilkołazka A. Modified polymeric biomaterials with antimicrobial and immunomodulating properties. Sci Rep 2024; 14:8025. [PMID: 38580807 PMCID: PMC10997598 DOI: 10.1038/s41598-024-58730-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 04/02/2024] [Indexed: 04/07/2024] Open
Abstract
The modification of the surgical polypropylene mesh and the polytetrafluoroethylene vascular prosthesis with cecropin A (small peptide) and puromycin (aminonucleoside) yielded very stable preparations of modified biomaterials. The main emphasis was placed on analyses of their antimicrobial activity and potential immunomodulatory and non-cytotoxic properties towards the CCD841 CoTr model cell line. Cecropin A did not significantly affect the viability or proliferation of the CCD 841 CoTr cells, regardless of its soluble or immobilized form. In contrast, puromycin did not induce a significant decrease in the cell viability or proliferation in the immobilized form but significantly decreased cell viability and proliferation when administered in the soluble form. The covalent immobilization of these two molecules on the surface of biomaterials resulted in stable preparations that were able to inhibit the multiplication of Staphylococcus aureus and S. epidermidis strains. It was also found that the preparations induced the production of cytokines involved in antibacterial protection mechanisms and stimulated the immune response. The key regulator of this activity may be related to TLR4, a receptor recognizing bacterial LPS. In the present study, these factors were produced not only in the conditions of LPS stimulation but also in the absence of LPS, which indicates that cecropin A- and puromycin-modified biomaterials may upregulate pathways leading to humoral antibacterial immune response.
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Affiliation(s)
- Katarzyna Szałapata
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka, 19, 20-033, Lublin, Poland
| | - Mateusz Pięt
- Department of Virology and Immunology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Martyna Kasela
- Department of Pharmaceutical Microbiology, Medical University of Lublin, Chodzki 1, 20-093, Lublin, Poland
| | - Marcin Grąz
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka, 19, 20-033, Lublin, Poland
| | - Justyna Kapral-Piotrowska
- Department of Functional Anatomy and Cytobiology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Aleksandra Mordzińska-Rak
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka, 19, 20-033, Lublin, Poland
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Chodzki 1, 20-093, Lublin, Poland
| | - Elżbieta Samorek
- Department of Virology and Immunology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
- Department of Pharmacology and Toxicology, National Veterinary Research Institute, Pulawy, Poland
| | - Paulina Pieniądz
- Department of Virology and Immunology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Jolanta Polak
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka, 19, 20-033, Lublin, Poland
| | - Monika Osińska-Jaroszuk
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka, 19, 20-033, Lublin, Poland
| | - Roman Paduch
- Department of Virology and Immunology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Bożena Pawlikowska-Pawlęga
- Department of Functional Anatomy and Cytobiology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Anna Malm
- Department of Pharmaceutical Microbiology, Medical University of Lublin, Chodzki 1, 20-093, Lublin, Poland
| | - Anna Jarosz-Wilkołazka
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Maria Curie-Sklodowska University, Akademicka, 19, 20-033, Lublin, Poland.
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Tian Y, Zhang M, Man H, Wu C, Wang Y, Kong L, Liu J. Study of ischemic progression in different intestinal tissue layers during acute intestinal ischemia using swept-source optical coherence tomography angiography. JOURNAL OF BIOPHOTONICS 2024; 17:e202300382. [PMID: 38247043 DOI: 10.1002/jbio.202300382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 01/04/2024] [Accepted: 01/04/2024] [Indexed: 01/23/2024]
Abstract
In acute intestinal ischemia, the progression of ischemia varies across different layers of intestinal tissue. We established a mouse model and used swept-source optical coherence tomography (OCT) to observe the intestinal ischemic process longitudinally in different tissue layers. Employing a method that combines asymmetric gradient filtering with adaptive weighting, we eliminated the vessel trailing phenomenon in OCT angiograms, reducing the confounding effects of superficial vessels on the imaging of deeper vasculature. We quantitatively assessed changes in vascular perfusion density (VPD), vessel length, and vessel average diameter across various intestinal layers. Our results showed a significant reduction in VPD in all layers during ischemia. The mucosa layer experienced the most significant impact, primarily due to disrupted capillary blood flow, followed by the submucosa layer, where vascular constriction or decreased velocity was the primary factor.
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Affiliation(s)
- Yu Tian
- Department of Surgical, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Mingshuo Zhang
- Hebei North University, Zhangjiakou, China
- Department of Hand & Foot Surgery, First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Hongbo Man
- Hebei North University, Zhangjiakou, China
- Department of Hand & Foot Surgery, First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Chunnan Wu
- Department of General Surgery, First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Yimin Wang
- Department of Surgical, Hebei Medical University, Shijiazhuang, Hebei Province, China
- Department of General Surgery, First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Linghui Kong
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, China
| | - Jian Liu
- School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, China
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Mirhaidari GJ, Barker JC, Breuer CK, Reinhardt JW. Implanted Tissue-Engineered Vascular Graft Cell Isolation with Single-Cell RNA Sequencing Analysis. Tissue Eng Part C Methods 2023; 29:72-84. [PMID: 36719780 PMCID: PMC9968626 DOI: 10.1089/ten.tec.2022.0189] [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: 11/12/2022] [Accepted: 01/17/2023] [Indexed: 02/01/2023] Open
Abstract
The advent of single-cell RNA sequencing (scRNA-Seq) has brought with it the ability to gain greater insights into the cellular composition of tissues and heterogeneity in gene expression within specific cell types. For tissue-engineered blood vessels, this is particularly impactful to better understand how neotissue forms and remodels into tissue resembling a native vessel. A notable challenge, however, is the ability to separate cells from synthetic biomaterials to generate high-quality single-cell suspensions to interrogate the cellular composition of our tissue-engineered vascular grafts (TEVGs) during active remodeling in situ. We present here a simple, commercially available approach to separate cells within our TEVG from the residual scaffold for downstream use in a scRNA-Seq workflow. Utilizing this method, we identified the cell populations comprising explanted TEVGs and compared these with results from immunohistochemical analysis. The process began with explanted TEVGs undergoing traditional mechanical and enzymatic dissociation to separate cells from scaffold and extracellular matrix proteins. Magnetically labeled antibodies targeting murine origin cells were incubated with enzymatic digests of TEVGs containing cells and scaffold debris in suspension allowing for separation by utilizing a magnetic separator column. Single-cell suspensions were processed through 10 × Genomics and data were analyzed utilizing R to generate cell clusters. Expression data provided new insights into a diverse composition of phenotypically unique subclusters within the fibroblast, macrophage, smooth muscle cell, and endothelial cell populations contributing to the early neotissue remodeling stages of TEVGs. These populations were correlated qualitatively and quantitatively with immunohistochemistry highlighting for the first time the potential of scRNA-Seq to provide exquisite detail into the host cellular response to an implanted TEVG. These results additionally demonstrate magnetic cell isolation is an effective method for generating high-quality cell suspensions for scRNA-Seq. While this method was utilized for our group's TEVGs, it has broader applications to other implantable materials that use biodegradable synthetic materials as part of scaffold composition. Impact statement Single-cell RNA sequencing is an evolving technology with the ability to provide detailed information on the cellular composition of remodeling biomaterials in vivo. This present work details an effective approach for separating nondegraded biomaterials from cells for downstream RNA-sequencing analysis. We applied this method to implanted tissue-engineered vascular grafts and for the first time describe the cellular composition of the remodeling graft at a single-cell gene expression level. While this method was effective in our scaffold, it has broad applicability to other implanted biomaterials that necessitate separation of cell from residual scaffold materials for single-cell RNA sequencing.
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Affiliation(s)
- Gabriel J.M. Mirhaidari
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Jenny C. Barker
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Plastic and Reconstructive Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Christopher K. Breuer
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - James W. Reinhardt
- Center for Regenerative Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
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Collier CA, Mendiondo C, Raghavan S. Tissue engineering of the gastrointestinal tract: the historic path to translation. J Biol Eng 2022; 16:9. [PMID: 35379299 PMCID: PMC8981633 DOI: 10.1186/s13036-022-00289-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/08/2022] [Indexed: 11/15/2022] Open
Abstract
The gastrointestinal (GI) tract is imperative for multiple functions including digestion, nutrient absorption, and timely waste disposal. The central feature of the gut is peristalsis, intestinal motility, which facilitates all of its functions. Disruptions in GI motility lead to sub-optimal GI function, resulting in a lower quality of life in many functional GI disorders. Over the last two decades, tissue engineering research directed towards the intestine has progressed rapidly due to advances in cell and stem-cell biology, integrative physiology, bioengineering and biomaterials. Newer biomedical tools (including optical tools, machine learning, and nuanced regenerative engineering approaches) have expanded our understanding of the complex cellular communication within the GI tract that lead to its orchestrated physiological function. Bioengineering therefore can be utilized towards several translational aspects: (i) regenerative medicine to remedy/restore GI physiological function; (ii) in vitro model building to mimic the complex physiology for drug and pharmacology testing; (iii) tool development to continue to unravel multi-cell communication networks to integrate cell and organ-level physiology. Despite the significant strides made historically in GI tissue engineering, fundamental challenges remain including the quest for identifying autologous human cell sources, enhanced scaffolding biomaterials to increase biocompatibility while matching viscoelastic properties of the underlying tissue, and overall biomanufacturing. This review provides historic perspectives for how bioengineering has advanced over time, highlights newer advances in bioengineering strategies, and provides a realistic perspective on the path to translation.
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Affiliation(s)
- Claudia A Collier
- Department of Biomedical Engineering, Texas A&M University, Emerging Technologies Building, 3120 TAMU, College Station, TX, 77843, USA
| | - Christian Mendiondo
- Department of Biomedical Engineering, Texas A&M University, Emerging Technologies Building, 3120 TAMU, College Station, TX, 77843, USA
| | - Shreya Raghavan
- Department of Biomedical Engineering, Texas A&M University, Emerging Technologies Building, 3120 TAMU, College Station, TX, 77843, USA. .,Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, USA.
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5
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Hirota A, AlMusawi S, Nateri AS, Ordóñez-Morán P, Imajo M. Biomaterials for intestinal organoid technology and personalized disease modeling. Acta Biomater 2021; 132:272-287. [PMID: 34023456 DOI: 10.1016/j.actbio.2021.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/08/2021] [Accepted: 05/07/2021] [Indexed: 12/20/2022]
Abstract
Recent advances in intestinal organoid technologies have paved the way for in vitro recapitulation of the homeostatic renewal of adult tissues, tissue or organ morphogenesis during development, and pathogenesis of many disorders. In vitro modelling of individual patient diseases using organoid systems have been considered key in establishing rational design of personalized treatment strategies and in improving therapeutic outcomes. In addition, the transplantation of organoids into diseased tissues represents a novel approach to treat currently incurable diseases. Emerging evidence from intensive studies suggests that organoid systems' development and functional maturation depends on the presence of an extracellular matrix with suitable biophysical properties, where advanced synthetic hydrogels open new avenues for theoretical control of organoid phenotypes and potential applications of organoids in therapeutic purposes. In this review, we discuss the status, applications, challenges and perspectives of intestinal organoid systems emphasising on hydrogels and their properties suitable for intestinal organoid culture. We provide an overview of hydrogels used for intestinal organoid culture and key factors regulating their biological activity. The comparison of different hydrogels would be a theoretical basis for establishing design principles of synthetic niches directing intestinal cell fates and functions. STATEMENT OF SIGNIFICANCE: Intestinal organoid is an in vitro recapitulation of the gut, which self-organizes from intestinal stem cells and maintains many features of the native tissue. Since the development of this technology, intestinal organoid systems have made significant contribution to rapid progress in intestinal biology. Prevailing methodology for organoid culture, however, depends on animal-derived matrices and suffers from variability and potential risk for contamination of pathogens, limiting their therapeutic application. Synthetic scaffold matrices, hydrogels, might provide solutions to these issues and deepen our understanding on how intestinal cells sense and respond to key biophysical properties of the surrounding matrices. This review provides an overview of developing intestinal models and biomaterials, thereby leading to better understanding of current intestinal organoid systems for both biologists and materials scientists.
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Affiliation(s)
- Akira Hirota
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, N15, W7, Kita-ku, Sapporo 060-8638, Japan
| | - Shaikha AlMusawi
- Cancer Genetic and Stem Cell group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom; Stem Cell biology and Cancer group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom
| | - Abdolrahman S Nateri
- Cancer Genetic and Stem Cell group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom
| | - Paloma Ordóñez-Morán
- Stem Cell biology and Cancer group, Translational Medical Sciences, School of Medicine, Biodiscovery Institute, Centre for Cancer Sciences, University of Nottingham, NG7 2RD, Nottingham, United Kingdom.
| | - Masamichi Imajo
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
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Balaphas A, Meyer J, Meier RPH, Liot E, Buchs NC, Roche B, Toso C, Bühler LH, Gonelle-Gispert C, Ris F. Cell Therapy for Anal Sphincter Incontinence: Where Do We Stand? Cells 2021; 10:2086. [PMID: 34440855 PMCID: PMC8394955 DOI: 10.3390/cells10082086] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 12/12/2022] Open
Abstract
Anal sphincter incontinence is a chronic disease, which dramatically impairs quality of life and induces high costs for the society. Surgery, considered as the best curative option, shows a disappointing success rate. Stem/progenitor cell therapy is pledging, for anal sphincter incontinence, a substitute to surgery with higher efficacy. However, the published literature is disparate. Our aim was to perform a review on the development of cell therapy for anal sphincter incontinence with critical analyses of its pitfalls. Animal models for anal sphincter incontinence were varied and tried to reproduce distinct clinical situations (acute injury or healed injury with or without surgical reconstruction) but were limited by anatomical considerations. Cell preparations used for treatment, originated, in order of frequency, from skeletal muscle, bone marrow or fat tissue. The characterization of these preparations was often incomplete and stemness not always addressed. Despite a lack of understanding of sphincter healing processes and the exact mechanism of action of cell preparations, this treatment was evaluated in 83 incontinent patients, reporting encouraging results. However, further development is necessary to establish the correct indications, to determine the most-suited cell type, to standardize the cell preparation method and to validate the route and number of cell delivery.
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Affiliation(s)
- Alexandre Balaphas
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
- Department of Surgery, Geneva Medical School, University of Geneva, 1205 Geneva, Switzerland
| | - Jeremy Meyer
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
| | - Raphael P. H. Meier
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Emilie Liot
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
| | - Nicolas C. Buchs
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
| | - Bruno Roche
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
| | - Christian Toso
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
| | - Leo H. Bühler
- Faculty of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland; (L.H.B.); (C.G.-G.)
| | - Carmen Gonelle-Gispert
- Faculty of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland; (L.H.B.); (C.G.-G.)
| | - Frédéric Ris
- Division of Digestive Surgery, University Hospitals of Geneva, 1205 Geneva, Switzerland; (J.M.); (E.L.); (N.C.B.); (B.R.); (C.T.); (F.R.)
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Boys AJ, Barron SL, Tilev D, Owens RM. Building Scaffolds for Tubular Tissue Engineering. Front Bioeng Biotechnol 2020; 8:589960. [PMID: 33363127 PMCID: PMC7758256 DOI: 10.3389/fbioe.2020.589960] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/04/2020] [Indexed: 12/15/2022] Open
Abstract
Hollow organs and tissue systems drive various functions in the body. Many of these hollow or tubular systems, such as vasculature, the intestines, and the trachea, are common targets for tissue engineering, given their relevance to numerous diseases and body functions. As the field of tissue engineering has developed, numerous benchtop models have been produced as platforms for basic science and drug testing. Production of tubular scaffolds for different tissue engineering applications possesses many commonalities, such as the necessity for producing an intact tubular opening and for formation of semi-permeable epithelia or endothelia. As such, the field has converged on a series of manufacturing techniques for producing these structures. In this review, we discuss some of the most common tissue engineered applications within the context of tubular tissues and the methods by which these structures can be produced. We provide an overview of the general structure and anatomy for these tissue systems along with a series of general design criteria for tubular tissue engineering. We categorize methods for manufacturing tubular scaffolds as follows: casting, electrospinning, rolling, 3D printing, and decellularization. We discuss state-of-the-art models within the context of vascular, intestinal, and tracheal tissue engineering. Finally, we conclude with a discussion of the future for these fields.
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Affiliation(s)
| | | | | | - Roisin M. Owens
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
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Das S, Gordián-Vélez WJ, Ledebur HC, Mourkioti F, Rompolas P, Chen HI, Serruya MD, Cullen DK. Innervation: the missing link for biofabricated tissues and organs. NPJ Regen Med 2020; 5:11. [PMID: 32550009 PMCID: PMC7275031 DOI: 10.1038/s41536-020-0096-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Innervation plays a pivotal role as a driver of tissue and organ development as well as a means for their functional control and modulation. Therefore, innervation should be carefully considered throughout the process of biofabrication of engineered tissues and organs. Unfortunately, innervation has generally been overlooked in most non-neural tissue engineering applications, in part due to the intrinsic complexity of building organs containing heterogeneous native cell types and structures. To achieve proper innervation of engineered tissues and organs, specific host axon populations typically need to be precisely driven to appropriate location(s) within the construct, often over long distances. As such, neural tissue engineering and/or axon guidance strategies should be a necessary adjunct to most organogenesis endeavors across multiple tissue and organ systems. To address this challenge, our team is actively building axon-based "living scaffolds" that may physically wire in during organ development in bioreactors and/or serve as a substrate to effectively drive targeted long-distance growth and integration of host axons after implantation. This article reviews the neuroanatomy and the role of innervation in the functional regulation of cardiac, skeletal, and smooth muscle tissue and highlights potential strategies to promote innervation of biofabricated engineered muscles, as well as the use of "living scaffolds" in this endeavor for both in vitro and in vivo applications. We assert that innervation should be included as a necessary component for tissue and organ biofabrication, and that strategies to orchestrate host axonal integration are advantageous to ensure proper function, tolerance, assimilation, and bio-regulation with the recipient post-implant.
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Affiliation(s)
- Suradip Das
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA USA
| | - Wisberty J. Gordián-Vélez
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
| | | | - Foteini Mourkioti
- Department of Orthopedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Panteleimon Rompolas
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - H. Isaac Chen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA USA
| | - Mijail D. Serruya
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA USA
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA USA
| | - D. Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA USA
- Axonova Medical, LLC., Philadelphia, PA USA
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9
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Chen Y, Guo C, Manousiouthakis E, Wang X, Cairns DM, Roh TT, Du C, Kaplan DL. Bi-layered Tubular Microfiber Scaffolds as Functional Templates for Engineering Human Intestinal Smooth Muscle Tissue. ADVANCED FUNCTIONAL MATERIALS 2020; 30:2000543. [PMID: 33692658 PMCID: PMC7938961 DOI: 10.1002/adfm.202000543] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Indexed: 05/09/2023]
Abstract
Designing biomimetic scaffolds with in vivo-like microenvironments using biomaterials is an essential component of successful tissue engineering approaches. The intestinal smooth muscle layers exhibit a complex tubular structure consisting of two concentric muscle layers in which the inner circular layer is orthogonally oriented to the outer longitudinal layer. Here, we present a three-dimensional (3D) bi-layered tubular scaffold based on flexible, mechanically robust and well aligned silk protein microfibers to mimic native human intestinal smooth muscle structure. The scaffolds were seeded with primary human intestinal smooth muscle cells to replicate human intestinal muscle tissues in vitro. Characterization of the tissue constructs revealed good biocompatibility and support for cell alignment and elongation in the different scaffold layers to enhance cell differentiation and functions. Furthermore, the engineered smooth muscle constructs supported oriented neurite outgrowth, a requisite step to achieve functional innervation. These results suggested these microfiber scaffolds as functional templates for in vitro regeneration of human intestinal smooth muscle systems. The scaffolding provides a crucial step toward engineering functional human intestinal tissue in vitro, as well as for the engineering of many other types of smooth muscles in terms of their similar phenotypes. Such utility may lead to a better understanding of smooth muscle associated diseases and treatments.
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Affiliation(s)
| | | | - Eleana Manousiouthakis
- Department of Biomedical Engineering, Tufts University, 4 Colby St.
Medford, Massachusetts 02155, USA
| | - Xiuli Wang
- Department of Biomedical Engineering, Tufts University, 4 Colby St.
Medford, Massachusetts 02155, USA
| | - Dana M. Cairns
- Department of Biomedical Engineering, Tufts University, 4 Colby St.
Medford, Massachusetts 02155, USA
| | - Terrence T. Roh
- Department of Biomedical Engineering, Tufts University, 4 Colby St.
Medford, Massachusetts 02155, USA
| | - Chuang Du
- Department of Biomedical Engineering, Tufts University, 4 Colby St.
Medford, Massachusetts 02155, USA
| | - David L. Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby St.
Medford, Massachusetts 02155, USA
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10
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Costa J, Ahluwalia A. Advances and Current Challenges in Intestinal in vitro Model Engineering: A Digest. Front Bioeng Biotechnol 2019; 7:144. [PMID: 31275931 PMCID: PMC6591368 DOI: 10.3389/fbioe.2019.00144] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/28/2019] [Indexed: 12/30/2022] Open
Abstract
The physiological environment of the intestine is characterized by its variegated composition, numerous functions and unique dynamic conditions, making it challenging to recreate the organ in vitro. This review outlines the requirements for engineering physiologically relevant intestinal in vitro models, mainly focusing on the importance of the mechano-structural cues that are often neglected in classic cell culture systems. More precisely: the topography, motility and flow present in the intestinal epithelium. After defining quantitative descriptors for these features, we describe the current state of the art, citing relevant approaches used to address one (or more) of the elements in question, pursuing a progressive conceptual construction of an "ideal" biomimetic intestinal model. The review concludes with a critical assessment of the currently available methods to summarize the important features of the intestinal tissue in the light of their different applications.
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Affiliation(s)
| | - Arti Ahluwalia
- Research Center “E. Piaggio” and Department of Information Engineering, University of Pisa, Pisa, Italy
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11
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Hassanzadeh P, Atyabi F, Dinarvand R. Tissue engineering: Still facing a long way ahead. J Control Release 2018; 279:181-197. [DOI: 10.1016/j.jconrel.2018.04.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/09/2018] [Accepted: 04/11/2018] [Indexed: 02/07/2023]
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12
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Jung KB, Lee H, Son YS, Lee JH, Cho HS, Lee MO, Oh JH, Lee J, Kim S, Jung CR, Kim J, Son MY. In vitro and in vivo imaging and tracking of intestinal organoids from human induced pluripotent stem cells. FASEB J 2018; 32:111-122. [PMID: 28855280 DOI: 10.1096/fj.201700504r] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/14/2017] [Indexed: 12/16/2022]
Abstract
Human intestinal organoids (hIOs) derived from human pluripotent stem cells (hPSCs) have immense potential as a source of intestines. Therefore, an efficient system is needed for visualizing the stage of intestinal differentiation and further identifying hIOs derived from hPSCs. Here, 2 fluorescent biosensors were developed based on human induced pluripotent stem cell (hiPSC) lines that stably expressed fluorescent reporters driven by intestine-specific gene promoters Krüppel-like factor 5 monomeric Cherry (KLF5mCherry) and intestine-specific homeobox enhanced green fluorescence protein (ISXeGFP). Then hIOs were efficiently induced from those transgenic hiPSC lines in which mCherry- or eGFP-expressing cells, which appeared during differentiation, could be identified in intact living cells in real time. Reporter gene expression had no adverse effects on differentiation into hIOs and proliferation. Using our reporter system to screen for hIO differentiation factors, we identified DMH1 as an efficient substitute for Noggin. Transplanted hIOs under the kidney capsule were tracked with fluorescence imaging (FLI) and confirmed histologically. After orthotopic transplantation, the localization of the hIOs in the small intestine could be accurately visualized using FLI. Our study establishes a selective system for monitoring the in vitro differentiation and for tracking the in vivo localization of hIOs and contributes to further improvement of cell-based therapies and preclinical screenings in the intestinal field.-Jung, K. B., Lee, H., Son, Y. S., Lee, J. H., Cho, H.-S., Lee, M.-O., Oh, J.-H., Lee, J., Kim, S., Jung, C.-R., Kim, J., Son, M.-Y. In vitro and in vivo imaging and tracking of intestinal organoids from human induced pluripotent stem cells.
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Affiliation(s)
- Kwang Bo Jung
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
| | - Hana Lee
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
| | - Ye Seul Son
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
| | - Ji Hye Lee
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Hyun-Soo Cho
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
| | - Mi-Ok Lee
- Immunotherapy Covergence Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Jung-Hwa Oh
- Korea Institute of Toxicology, Daejeon, South Korea; and
| | - Jaemin Lee
- Aging Research Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Seokho Kim
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
- Aging Research Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Cho-Rok Jung
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
| | - Janghwan Kim
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea,
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
| | - Mi-Young Son
- Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea,
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, South Korea
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The extracellular matrix of the gastrointestinal tract: a regenerative medicine platform. Nat Rev Gastroenterol Hepatol 2017; 14:540-552. [PMID: 28698662 DOI: 10.1038/nrgastro.2017.76] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The synthesis and secretion of components that constitute the extracellular matrix (ECM) by resident cell types occur at the earliest stages of embryonic development, and continue throughout life in both healthy and diseased physiological states. The ECM consists of a complex mixture of insoluble and soluble functional components that are arranged in a tissue-specific 3D ultrastructure, and it regulates numerous biological processes, including angiogenesis, innervation and stem cell differentiation. Owing to its composition and influence on embryonic development, as well as cellular and organ homeostasis, the ECM is an ideal therapeutic substrate for the repair of damaged or diseased tissues. Biologic scaffold materials that are composed of ECM have been used in various surgical and tissue-engineering applications. The gastrointestinal (GI) tract presents distinct challenges, such as diverse pH conditions and the requirement for motility and nutrient absorption. Despite these challenges, the use of homologous and heterologous ECM bioscaffolds for the focal or segmental reconstruction and regeneration of GI tissue has shown promise in early preclinical and clinical studies. This Review discusses the importance of tissue-specific ECM bioscaffolds and highlights the major advances that have been made in regenerative medicine strategies for the reconstruction of functional GI tissues.
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14
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Tubular collagen scaffolds with radial elasticity for hollow organ regeneration. Acta Biomater 2017; 52:1-8. [PMID: 28179160 DOI: 10.1016/j.actbio.2017.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/24/2017] [Accepted: 02/02/2017] [Indexed: 01/05/2023]
Abstract
Tubular collagen scaffolds have been used for the repair of damaged hollow organs in regenerative medicine, but they generally lack the ability to reversibly expand in radial direction, a physiological characteristic seen in many native tubular organs. In this study, tubular collagen scaffolds were prepared that display a shape recovery effect and therefore exhibit radial elasticity. Scaffolds were constructed by compression of fibrillar collagen around a star-shaped mandrel, mimicking folds in a lumen, a typical characteristic of empty tubular hollow organs, such as ureter or urethra. Shape recovery effect was introduced by in situ fixation using a star-shaped mandrel, 3D-printed clamps and cytocompatible carbodiimide crosslinking. Prepared scaffolds expanded upon increase of luminal pressure and closed to the star-shaped conformation after removal of pressure. In this study, we applied this method to construct a scaffold mimicking the dynamics of human urethra. Radial expansion and closure of the scaffold could be iteratively performed for at least 1000 cycles, burst pressure being 132±22mmHg. Scaffolds were seeded with human epithelial cells and cultured in a bioreactor under dynamic conditions mimicking urination (pulse flow of 21s every 2h). Cells adhered and formed a closed luminal layer that resisted flow conditions. In conclusion, a new type of a tubular collagen scaffold has been constructed with radial elastic-like characteristics based on the shape of the scaffold, and enabling the scaffold to reversibly expand upon increase in luminal pressure. These scaffolds may be useful for regenerative medicine of tubular organs. STATEMENT OF SIGNIFICANCE In this paper, a new type I collagen-based tubular scaffold is presented that possesses intrinsic radial elasticity. This characteristic is key to the functioning of a number of tubular organs including blood vessels and organs of the gastrointestinal and urogenital tract. The scaffold was given a star-shaped lumen by physical compression and chemical crosslinking, mimicking the folding pattern observed in many tubular organs. In rest, the lumen is closed but it opens upon increase of luminal pressure, e.g. when fluids pass. Human epithelial cells seeded on the luminal side adhered well and were compatible with voiding dynamics in a bioreactor. Collagen scaffolds with radial elasticity may be useful in the regeneration of dynamic tubular organs.
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Hendow EK, Guhmann P, Wright B, Sofokleous P, Parmar N, Day RM. Biomaterials for hollow organ tissue engineering. FIBROGENESIS & TISSUE REPAIR 2016; 9:3. [PMID: 27014369 PMCID: PMC4806416 DOI: 10.1186/s13069-016-0040-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/15/2016] [Indexed: 12/14/2022]
Abstract
Tissue engineering is a rapidly advancing field that is likely to transform how medicine is practised in the near future. For hollow organs such as those found in the cardiovascular and respiratory systems or gastrointestinal tract, tissue engineering can provide replacement of the entire organ or provide restoration of function to specific regions. Larger tissue-engineered constructs often require biomaterial-based scaffold structures to provide support and structure for new tissue growth. Consideration must be given to the choice of material and manufacturing process to ensure the de novo tissue closely matches the mechanical and physiological properties of the native tissue. This review will discuss some of the approaches taken to date for fabricating hollow organ scaffolds and the selection of appropriate biomaterials.
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Affiliation(s)
- Eseelle K. Hendow
- Applied Biomedical Engineering Group, Division of Medicine, University College London, 21 University Street, London, UK
| | - Pauline Guhmann
- Applied Biomedical Engineering Group, Division of Medicine, University College London, 21 University Street, London, UK
| | - Bernice Wright
- Applied Biomedical Engineering Group, Division of Medicine, University College London, 21 University Street, London, UK
| | - Panagiotis Sofokleous
- Applied Biomedical Engineering Group, Division of Medicine, University College London, 21 University Street, London, UK
| | - Nina Parmar
- Applied Biomedical Engineering Group, Division of Medicine, University College London, 21 University Street, London, UK
| | - Richard M. Day
- Applied Biomedical Engineering Group, Division of Medicine, University College London, 21 University Street, London, UK
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16
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Khalil HA, Lei NY, Brinkley G, Scott A, Wang J, Kar UK, Jabaji ZB, Lewis M, Martín MG, Dunn JCY, Stelzner MG. A novel culture system for adult porcine intestinal crypts. Cell Tissue Res 2016; 365:123-34. [PMID: 26928041 DOI: 10.1007/s00441-016-2367-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 01/19/2016] [Indexed: 12/29/2022]
Abstract
Porcine models are useful for investigating therapeutic approaches to short bowel syndrome and potentially to intestinal stem cell (ISC) transplantation. Whereas techniques for the culture and genetic manipulation of ISCs from mice and humans are well established, similar methods for porcine stem cells have not been reported. Jejunal crypts were isolated from murine, human, and juvenile and adult porcine small intestine, suspended in Matrigel, and co-cultured with syngeneic intestinal subepithelial myofibroblasts (ISEMFs) or cultured without feeder cells in various culture media. Media containing epidermal growth factor, noggin, and R-spondin 1 (ENR medium) were supplemented with various combinations of Wnt3a- or ISEMF-conditioned medium (CM) and with glycogen synthase kinase 3 inhibitor (GSK3i), and their effects were studied on cultured crypts. Cell lineage differentiation was assessed by immunohistochemistry and quantitative polymerase chain reaction. Cultured porcine cells were serially passaged and transduced with a lentiviral vector. Whereas ENR medium supported murine enteroid growth, it did not sustain porcine crypts beyond 5 days. Supplementation of Wnt3a-CM and GSK3i resulted in the formation of complex porcine enteroids with budding extensions. These enteroids contained a mixture of stem and differentiated cells and were successfully passaged in the presence of GSK3i. Crypts grown in media supplemented with porcine ISEMF-CM formed spheroids that were less well differentiated than enteroids. Enteroids and spheroids were transfected with a lentivirus with high efficiency. Thus, our method maintains juvenile and adult porcine crypt cells long-term in culture. Porcine enteroids and spheroids can be successfully passaged and transduced by using lentiviral vectors.
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Affiliation(s)
- Hassan A Khalil
- Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Nan Ye Lei
- Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Garrett Brinkley
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and the David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, USA
| | - Andrew Scott
- Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Jiafang Wang
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and the David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, USA
| | - Upendra K Kar
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and the David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ziyad B Jabaji
- Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Michael Lewis
- Department of Pathology & Laboratory Medicine, VA Greater Los Angeles Health System, Los Angeles, CA, USA
| | - Martín G Martín
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and the David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, USA
| | - James C Y Dunn
- Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Matthias G Stelzner
- Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, CA, USA.
- Department of Surgery, VA Greater Los Angeles Health System, Los Angeles, CA, USA.
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17
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Lehur PA, Duchalais E. Other options in the treatment of fecal incontinence. SEMINARS IN COLON AND RECTAL SURGERY 2016. [DOI: 10.1053/j.scrs.2015.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Fattorini E, Brusa T, Gingert C, Hieber SE, Leung V, Osmani B, Dominietto MD, Büchler P, Hetzer F, Müller B. Artificial Muscle Devices: Innovations and Prospects for Fecal Incontinence Treatment. Ann Biomed Eng 2016; 44:1355-69. [PMID: 26926695 PMCID: PMC4837210 DOI: 10.1007/s10439-016-1572-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 02/17/2016] [Indexed: 01/10/2023]
Abstract
Fecal incontinence describes the involuntary loss of bowel content, which is responsible for stigmatization and social exclusion. It affects about 45% of retirement home residents and overall more than 12% of the adult population. Severe fecal incontinence can be treated by the implantation of an artificial sphincter. Currently available implants, however, are not part of everyday surgery due to long-term re-operation rates of 95% and definitive explantation rates of 40%. Such figures suggest that the implants fail to reproduce the capabilities of the natural sphincter. This article reviews the artificial sphincters on the market and under development, presents their physical principles of operation and critically analyzes their performance. We highlight the geometrical and mechanical parameters crucial for the design of an artificial fecal sphincter and propose more advanced mechanisms of action for a biomimetic device with sensory feedback. Dielectric electro-active polymer actuators are especially attractive because of their versatility, response time, reaction forces, and energy consumption. The availability of such technology will enable fast pressure adaption comparable to the natural feedback mechanism, so that tissue atrophy and erosion can be avoided while maintaining continence during daily activities.
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Affiliation(s)
- Elisa Fattorini
- Department of Surgery and Orthopedics, Hospitals Schaffhausen, 8200, Schaffhausen, Switzerland.,Biomaterials Science Center, University of Basel, 4123, Allschwil, Switzerland
| | - Tobia Brusa
- Institute for Surgical Technology & Biomechanics, University of Bern, 3014, Bern, Switzerland
| | - Christian Gingert
- Department of Surgery and Orthopedics, Hospitals Schaffhausen, 8200, Schaffhausen, Switzerland.,Department of Medicine, University of Witten/Herdecke, 58448, Witten, Germany
| | - Simone E Hieber
- Biomaterials Science Center, University of Basel, 4123, Allschwil, Switzerland
| | - Vanessa Leung
- Biomaterials Science Center, University of Basel, 4123, Allschwil, Switzerland
| | - Bekim Osmani
- Biomaterials Science Center, University of Basel, 4123, Allschwil, Switzerland
| | - Marco D Dominietto
- Department of Surgery and Orthopedics, Hospitals Schaffhausen, 8200, Schaffhausen, Switzerland.,Biomaterials Science Center, University of Basel, 4123, Allschwil, Switzerland
| | - Philippe Büchler
- Institute for Surgical Technology & Biomechanics, University of Bern, 3014, Bern, Switzerland
| | - Franc Hetzer
- Department of Surgery and Orthopedics, Hospitals Schaffhausen, 8200, Schaffhausen, Switzerland
| | - Bert Müller
- Biomaterials Science Center, University of Basel, 4123, Allschwil, Switzerland.
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Keane TJ, Dziki J, Castelton A, Faulk DM, Messerschmidt V, Londono R, Reing JE, Velankar SS, Badylak SF. Preparation and characterization of a biologic scaffold and hydrogel derived from colonic mucosa. J Biomed Mater Res B Appl Biomater 2015; 105:291-306. [DOI: 10.1002/jbm.b.33556] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/28/2015] [Accepted: 10/11/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Timothy J. Keane
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
- Department of Bioengineering; University of Pittsburgh; Pittsburgh Pennsylvania 15213
| | - Jenna Dziki
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
- Department of Bioengineering; University of Pittsburgh; Pittsburgh Pennsylvania 15213
| | - Arthur Castelton
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
| | - Denver M. Faulk
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
- Department of Bioengineering; University of Pittsburgh; Pittsburgh Pennsylvania 15213
| | | | - Ricardo Londono
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
| | - Janet E. Reing
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
| | - Sachin S. Velankar
- Department of Chemical and Petroleum Engineering; University of Pittsburgh; Pittsburgh Pennsylvania 15213
| | - Stephen F. Badylak
- McGowan Institute for Regenerative Medicine; Pittsburgh Pennsylvania 15219
- Department of Bioengineering; University of Pittsburgh; Pittsburgh Pennsylvania 15213
- Department of Surgery; University of Pittsburgh; Pittsburgh Pennsylvania 15219
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Jain A, Bansal R. Applications of regenerative medicine in organ transplantation. J Pharm Bioallied Sci 2015; 7:188-94. [PMID: 26229352 PMCID: PMC4517320 DOI: 10.4103/0975-7406.160013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Revised: 01/30/2015] [Accepted: 02/14/2015] [Indexed: 12/14/2022] Open
Abstract
A worldwide shortage of organs for clinical implantation establishes the need to bring forward and test new technologies that will help in solving the problem. The concepts of regenerative medicine hold the potential for augmenting organ function or repairing damaged organ or allowing regeneration of deteriorated organs and tissue. Researchers are exploring possible regenerative medicine applications in organ transplantation so that coming together of the two fields can benefit each other. The present review discusses the strategies that are being implemented to regenerate or bio-engineer human organs for clinical purposes. It also highlights the limitations of the regenerative medicine that needs to be addressed to explore full potential of the field. A web-based research on MEDLINE was done using keywords “regenerative medicine,” “tissue-engineering,” “bio-engineered organs,” “decellularized scaffold” and “three-dimensional printing.” This review screened about 170 articles to get the desired knowledge update.
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Affiliation(s)
- Aditya Jain
- Department of Physiology, Government Medical College, Patiala, Punjab, India
| | - Ramta Bansal
- Department of Conservative Dentistry and Endodontics, Institute of Dental Sciences, Sehora, Jammu and Kashmir, India
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Parmar N, Kumar L, Emmanuel A, Day RM. Prospective regenerative medicine therapies for obstetric trauma-induced fecal incontinence. Regen Med 2015; 9:831-40. [PMID: 25431918 DOI: 10.2217/rme.14.56] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fecal incontinence is a major public health issue that has yet to be adequately addressed. Obstetric trauma and injury to the anal sphincter muscles are the most common cause of fecal incontinence. New therapies are emerging aimed at repair or regeneration of sphincter muscle and restoration of continence. While regenerative medicine offers an attractive option for fecal incontinence there are currently no validated techniques using this approach. Although many challenges are yet to be resolved, the advent of regenerative medicine is likely to offer disruptive technologies to treat and possibly prevent the onset of this devastating condition. This article provides a review on regenerative medicine approaches for treating fecal incontinence and a critique of the current landscape in this area.
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Affiliation(s)
- Nina Parmar
- Applied Biomedical Engineering Group, University College London, 21 University Street, London, WC1E 6JJ, UK
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Porcine models of digestive disease: the future of large animal translational research. Transl Res 2015; 166:12-27. [PMID: 25655839 PMCID: PMC4458388 DOI: 10.1016/j.trsl.2015.01.004] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 01/03/2015] [Accepted: 01/07/2015] [Indexed: 12/14/2022]
Abstract
There is increasing interest in nonrodent translational models for the study of human disease. The pig, in particular, serves as a useful animal model for the study of pathophysiological conditions relevant to the human intestine. This review assesses currently used porcine models of gastrointestinal physiology and disease and provides a rationale for the use of these models for future translational studies. The pig has proven its utility for the study of fundamental disease conditions such as ischemia-reperfusion injury, stress-induced intestinal dysfunction, and short bowel syndrome. Pigs have also shown great promise for the study of intestinal barrier function, surgical tissue manipulation and intervention, as well as biomaterial implantation and tissue transplantation. Advantages of pig models highlighted by these studies include the physiological similarity to human intestine and mechanisms of human disease. Emerging future directions for porcine models of human disease include the fields of transgenics and stem cell biology, with exciting implications for regenerative medicine.
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Barriga-Rivera A, Vinuesa JL, Lopez-Alonso M. Anorectal Manometry in Wistar Rats with Inexpensive Setup: A Physiological Description of the Mechanical Activity. J Med Biol Eng 2015. [DOI: 10.1007/s40846-015-0025-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Liu Y, Rager T, Johnson J, Enmark J, Besner GE. Enriched Intestinal Stem Cell Seeding Improves the Architecture of Tissue-Engineered Intestine. Tissue Eng Part C Methods 2015; 21:816-24. [PMID: 25603285 DOI: 10.1089/ten.tec.2014.0389] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE To develop a methodology to separate intestinal stem cell (ISC)-enriched crypts from differentiated epithelial cell (DEC)-containing villi to improve the morphology of tissue-engineered intestine (TEI). METHODS Small intestinal tissues from 5- to 7-day-old transgenic Lgr5-EGFP mice (with fluorescently labeled ISCs) were used to measure the height of villi and the depth of crypts. Based on the significant size difference between crypts and villi, a novel cell filtration system was developed. Filtration of mixed organoid units from full-thickness intestine of transgenic Lgr5-EGFP mice allowed determination of the percentage of ISCs in the different size-based filtration fractions obtained. In vivo, 5-7-day-old Lewis rat pups were used as cell donors to obtain purified crypts and villi, and the dams of the pups served as recipients. Flat and tubular polyglycolic acid (PGA) scaffolds were seeded with either ISC-enriched crypts or DEC-containing villi and implanted intra-abdominally on the anterior abdominal wall. After 1, 3, 7, 14, 21, and 28 days of in vivo incubation, explants were processed for histologic evaluation. RESULTS Small intestine from transgenic Lgr5-EGFP mice contained villi with an average height of 134.89±41.91 μm and crypts with an average depth of 49.59±8.95 μm. After filtration, we found that the 100-200 μm fractions contained relatively pure villi in which DECs were located, whereas the 25-70 μm range fractions contained concentrated crypts in which ISCs were located. In vivo, flat PGA scaffolds implanted with purified crypts formed well-developed mucosa by day 14 postimplantation, whereas flat scaffolds seeded with villi were replaced with fibrous tissue. Tubular scaffolds seeded with the crypt fraction developed a well-formed mucosal layer on the interior surface, with 80.9% circumferential mucosal engraftment and an average villous height of 478±65 μm, which was very close to native intestine (512±98 μm), whereas tubular scaffolds seeded with the villous fraction only had 21.7% circumferential mucosal engraftment and an average villous height of 243±78 μm. CONCLUSION The novel filtration system described can effectively and efficiently isolate ISC-containing crypts. TEI produced from ISC-containing crypts has an improved morphology that is similar to native intestine.
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Affiliation(s)
- Yanchun Liu
- 1 Department of Pediatric Surgery and The Research Institute at Nationwide Children's Hospital , Columbus, Ohio
| | - Terrence Rager
- 1 Department of Pediatric Surgery and The Research Institute at Nationwide Children's Hospital , Columbus, Ohio
| | | | | | - Gail E Besner
- 1 Department of Pediatric Surgery and The Research Institute at Nationwide Children's Hospital , Columbus, Ohio
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Tossas K, Qi-Huang S, Cuyar E, García-Arrarás JE. Temporal and spatial analysis of enteric nervous system regeneration in the sea cucumber Holothuria glaberrima. ACTA ACUST UNITED AC 2014; 1:10-26. [PMID: 27499861 PMCID: PMC4895299 DOI: 10.1002/reg2.15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 01/18/2023]
Abstract
There is limited information on the regeneration of the enteric nervous system (ENS) following major reconstruction of the digestive tract. We have studied ENS regeneration in the sea cucumber Holothuria glaberrima which undergoes an organogenic process forming a new digestive tract at the tip of the mesentery. Our results show that (1) a degeneration of nerve fibers occurs early in the regeneration process, prior to eventual regeneration; (2) nerve fibers that innervate the regenerating intestine are of extrinsic and intrinsic origin; (3) innervation by extrinsic fibers occurs in a gradient that begins in the proximal area of the regenerate; (4) late events include the appearance of nerve fibers that project from the serosa into the connective tissue and of nerve bundles in the mesothelial layer; (5) neurons and neuroendocrine cells appear early following the formation of the epithelial layers. Our results provide not only a comparative biological approach to study ENS regeneration but also an alternative point of view for the study of enteric neuropathologies and for the innervation of organs made in vitro.
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Affiliation(s)
- Karen Tossas
- Department of Biology University of Puerto Rico Rio Piedras Puerto Rico 00931
| | - Sunny Qi-Huang
- Department of Biology University of Puerto Rico Rio Piedras Puerto Rico 00931
| | - Eugenia Cuyar
- Department of Biology University of Puerto Rico Rio Piedras Puerto Rico 00931
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Intestinal stem cells and stem cell-based therapy for intestinal diseases. Cytotechnology 2014; 67:177-89. [PMID: 24981313 DOI: 10.1007/s10616-014-9753-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/07/2014] [Indexed: 01/17/2023] Open
Abstract
Currently, many gastrointestinal diseases are a major reason for the increased mortality rate of children and adults every year. Additionally, these patients may cope with the high cost of the parenteral nutrition (PN), which aids in the long-term survival of the patients. Other treatment options include surgical lengthening, which is not sufficient in many cases, and intestinal transplantation. However, intestinal transplantation is still accompanied by many challenges, including immune rejection and donor availability, which may limit the transplant's success. The development of more safe and promising alternative treatments for intestinal diseases is still ongoing. Stem cell-based therapy (SCT) and tissue engineering (TE) appear to be the next promising choices for the regeneration of the damaged intestine. However, suitable stem cell source is required for the SCT and TE process. Thus, in this review we discuss how intestinal stem cells (ISCs) are a promising cell source for small intestine diseases. We will also discuss the different markers were used to identify ISCs. Moreover, we discuss the dominant Wnt signaling pathway in the ISC niche and its involvement in some intestinal diseases. Additionally, we discuss ISC culture and expansion, which are critical to providing enough cells for SCT and TE. Finally, we conclude and recommend that ISC isolation, culture and expansion should be considered when SCT is a treatment option for intestinal disorders. Therefore, we believe that ISCs should be considered a cell source for SCT for many gastrointestinal diseases and should be highlighted in future clinical applications.
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Affiliation(s)
- John H Scholefield
- Division of Surgery, Queen's Medical Centre, University Hospital Nottingham, Nottingham, UK
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Bharucha AE, Rao SSC. An update on anorectal disorders for gastroenterologists. Gastroenterology 2014; 146:37-45.e2. [PMID: 24211860 PMCID: PMC3913170 DOI: 10.1053/j.gastro.2013.10.062] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/21/2013] [Accepted: 10/22/2013] [Indexed: 01/13/2023]
Abstract
Gastroenterologists frequently encounter pelvic floor disorders, which affect 10% to 15% of the population. The anorectum is a complex organ that collaborates with the pelvic floor muscles to preserve fecal continence and enable defecation. A careful clinical assessment is critical for the diagnosis and management of defecatory disorders and fecal incontinence. Newer diagnostic tools (eg, high-resolution manometry and magnetic resonance defecography) provide a refined understanding of anorectal dysfunctions and identify phenotypes in defecatory disorders and fecal incontinence. Conservative approaches, including biofeedback therapy, are the mainstay for managing these disorders; new minimally invasive approaches may benefit a subset of patients with fecal incontinence, but more controlled studies are needed. This mini-review highlights advances, current concepts, and controversies in the area.
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Affiliation(s)
- Adil E Bharucha
- Clinical Enteric Neuroscience Translational and Epidemiological Research Program, Division of Gastroenterology and Hepatology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota
| | - Satish S C Rao
- Section of Gastroenterology/Hepatology, Department of Internal Medicine, Medical College of Georgia, Georgia Regents University, Augusta, Georgia.
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Fuller MK, Faulk DM, Sundaram N, Mahe MM, Stout KM, von Furstenberg RJ, Smith BJ, McNaughton KK, Shroyer NF, Helmrath MA, Henning SJ. Intestinal stem cells remain viable after prolonged tissue storage. Cell Tissue Res 2013; 354:441-50. [PMID: 23820734 DOI: 10.1007/s00441-013-1674-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 05/27/2013] [Indexed: 12/12/2022]
Abstract
Intestinal stem cells (ISCs) are responsible for renewal of the epithelium both during normal homeostasis and following injury. As such, they have significant therapeutic potential. However, whether ISCs can survive tissue storage is unknown. We hypothesize that, although the majority of epithelial cells might die, ISCs would remain viable for at least 24 h at 4 °C. To explore this hypothesis, jejuna of C57Bl6/J or Lgr5-LacZ mice were removed and either processed immediately or placed in phosphate-buffered saline at 4 °C. Delayed isolation of epithelium was performed after 24, 30, or 48 h storage. At the light microscope level, despite extensive apoptosis of villus epithelial cells, small intestinal crypts remained morphologically intact for 30 h and ISCs were identifiable via Lgr5-LacZ positivity. Electron microscopy showed that ISCs retained high integrity for 24 h. When assessed by flow cytometry, ISCs were more resistant to degeneration than the rest of the epithelium, including neighboring Paneth cells, with higher viability across all time points. Cultured isolated crypts showed no loss of capacity to form complex enteroids after 24 h tissue storage, with efficiencies after 7 days of culture remaining above 80 %. By 30 h storage, efficiencies declined but budding capability was retained. We conclude that, with delay in isolation, ISCs remain viable and retain their proliferative capacity. In contrast, the remainder of the epithelium, including the Paneth cells, exhibits degeneration and programmed cell death. If these findings are recapitulated in human tissue, storage at 4 °C might offer a valuable temporal window for the harvesting of crypts or ISCs for therapeutic application.
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Affiliation(s)
- Megan K Fuller
- Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Carmona-Ribeiro AM, de Melo Carrasco LD. Cationic antimicrobial polymers and their assemblies. Int J Mol Sci 2013; 14:9906-46. [PMID: 23665898 PMCID: PMC3676821 DOI: 10.3390/ijms14059906] [Citation(s) in RCA: 307] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/20/2013] [Accepted: 04/23/2013] [Indexed: 12/21/2022] Open
Abstract
Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs). The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications.
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Affiliation(s)
- Ana Maria Carmona-Ribeiro
- Biocolloids Lab, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Caixa Postal 26077-05513-970, São Paulo, Brazil; E-Mail:
| | - Letícia Dias de Melo Carrasco
- Biocolloids Lab, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Caixa Postal 26077-05513-970, São Paulo, Brazil; E-Mail:
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, CEP 05508-900, São Paulo, Brazil
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31
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Sasikala M, Rao GV, Tandan M, Reddy DN. Gastro Intestinal Stem Cells. Regen Med 2013. [DOI: 10.1007/978-94-007-5690-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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32
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Esophageal and Gastrointestinal Tissue Engineering. Biomater Sci 2013. [DOI: 10.1016/b978-0-08-087780-8.00121-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sanders KM, Koh SD, Ro S, Ward SM. Regulation of gastrointestinal motility--insights from smooth muscle biology. Nat Rev Gastroenterol Hepatol 2012; 9:633-45. [PMID: 22965426 PMCID: PMC4793911 DOI: 10.1038/nrgastro.2012.168] [Citation(s) in RCA: 270] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Gastrointestinal motility results from coordinated contractions of the tunica muscularis, the muscular layers of the alimentary canal. Throughout most of the gastrointestinal tract, smooth muscles are organized into two layers of circularly or longitudinally oriented muscle bundles. Smooth muscle cells form electrical and mechanical junctions between cells that facilitate coordination of contractions. Excitation-contraction coupling occurs by Ca(2+) entry via ion channels in the plasma membrane, leading to a rise in intracellular Ca(2+). Ca(2+) binding to calmodulin activates myosin light chain kinase; subsequent phosphorylation of myosin initiates cross-bridge cycling. Myosin phosphatase dephosphorylates myosin to relax muscles, and a process known as Ca(2+) sensitization regulates the activity of the phosphatase. Gastrointestinal smooth muscles are 'autonomous' and generate spontaneous electrical activity (slow waves) that does not depend upon input from nerves. Intrinsic pacemaker activity comes from interstitial cells of Cajal, which are electrically coupled to smooth muscle cells. Patterns of contractile activity in gastrointestinal muscles are determined by inputs from enteric motor neurons that innervate smooth muscle cells and interstitial cells. Here we provide an overview of the cells and mechanisms that generate smooth muscle contractile behaviour and gastrointestinal motility.
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Wong VW, Wan DC, Gurtner GC, Longaker MT. Regenerative Surgery: Tissue Engineering in General Surgical Practice. World J Surg 2012; 36:2288-99. [DOI: 10.1007/s00268-012-1710-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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