1
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Toftdal MS, Grunnet LG, Chen M. Emerging Strategies for Beta Cell Encapsulation for Type 1 Diabetes Therapy. Adv Healthc Mater 2024; 13:e2400185. [PMID: 38452393 DOI: 10.1002/adhm.202400185] [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: 01/17/2024] [Revised: 02/28/2024] [Indexed: 03/09/2024]
Abstract
Diabetes is a prevalent chronic disease affecting millions of people globally. To address this health challenge, advanced beta cell therapy using biomaterials-based macroscale, microscale, and nanoscale encapsulation devices must tackle various obstacles. First, overcoming foreign body responses is a major focus of research. Strategies such as immunomodulatory materials and physical immunoshielding are investigated to reduce the immune response and improve the longevity of the encapsulated cells. Furthermore, oxygenating strategies, such as the use of oxygen-releasing biomaterials, are developed to improve oxygen diffusion and promote cell survival. Finally, yet importantly, promoting vascularization through the use of angiogenic growth factors and the incorporation of pre-vascularized materials are also explored to enhance nutrient and oxygen supply to the encapsulated cells. This review seeks to specifically highlight the emerging research strategies developed to overcome these challenges using micro and nanoscale biomaterial encapsulation devices. Continuously improving and refining these strategies make an advance toward realizing the improved therapeutic potential of the encapsulated beta cells.
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Affiliation(s)
- Mette Steen Toftdal
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus C, 8000, Denmark
- Department of Cell Formulation and Delivery, Novo Nordisk A/S, Måløv, 2760, Denmark
| | - Lars Groth Grunnet
- Department of Cell Formulation and Delivery, Novo Nordisk A/S, Måløv, 2760, Denmark
| | - Menglin Chen
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus C, 8000, Denmark
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2
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Zoneff E, Wang Y, Jackson C, Smith O, Duchi S, Onofrillo C, Farrugia B, Moulton SE, Williams R, Parish C, Nisbet DR, Caballero-Aguilar LM. Controlled oxygen delivery to power tissue regeneration. Nat Commun 2024; 15:4361. [PMID: 38778053 PMCID: PMC11111456 DOI: 10.1038/s41467-024-48719-x] [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: 11/07/2023] [Accepted: 05/13/2024] [Indexed: 05/25/2024] Open
Abstract
Oxygen plays a crucial role in human embryogenesis, homeostasis, and tissue regeneration. Emerging engineered regenerative solutions call for novel oxygen delivery systems. To become a reality, these systems must consider physiological processes, oxygen release mechanisms and the target application. In this review, we explore the biological relevance of oxygen at both a cellular and tissue level, and the importance of its controlled delivery via engineered biomaterials and devices. Recent advances and upcoming trends in the field are also discussed with a focus on tissue-engineered constructs that could meet metabolic demands to facilitate regeneration.
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Affiliation(s)
- Elizabeth Zoneff
- The Graeme Clark Institute, The University of Melbourne, Parkville, Melbourne, VIC, Australia
- Department of Biomedical Engineering, Faculty of Engineering and Information Technology, The University of Melbourne, Parkville, Melbourne, VIC, Australia
| | - Yi Wang
- The Graeme Clark Institute, The University of Melbourne, Parkville, Melbourne, VIC, Australia
- Department of Biomedical Engineering, Faculty of Engineering and Information Technology, The University of Melbourne, Parkville, Melbourne, VIC, Australia
| | - Colin Jackson
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia
- ARC Centre of Excellence in Synthetic Biology, Australian National University, Canberra, ACT, Australia
| | - Oliver Smith
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia
- ARC Centre of Excellence in Synthetic Biology, Australian National University, Canberra, ACT, Australia
| | - Serena Duchi
- Department of Surgery, Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Melbourne, VIC, Australia
- Aikenhead Centre for Medical Discovery, St. Vincent's Hospital, Melbourne, VIC, Australia
| | - Carmine Onofrillo
- Department of Surgery, Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Melbourne, VIC, Australia
- Aikenhead Centre for Medical Discovery, St. Vincent's Hospital, Melbourne, VIC, Australia
| | - Brooke Farrugia
- Department of Biomedical Engineering, Faculty of Engineering and Information Technology, The University of Melbourne, Parkville, Melbourne, VIC, Australia
| | - Simon E Moulton
- Aikenhead Centre for Medical Discovery, St. Vincent's Hospital, Melbourne, VIC, Australia
- Department of Engineering Technologies, Swinburne University of Technology, Melbourne, VIC, Australia
- Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, VIC, Australia
| | - Richard Williams
- IMPACT, School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Clare Parish
- The Florey Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - David R Nisbet
- The Graeme Clark Institute, The University of Melbourne, Parkville, Melbourne, VIC, Australia.
- Department of Biomedical Engineering, Faculty of Engineering and Information Technology, The University of Melbourne, Parkville, Melbourne, VIC, Australia.
- Melbourne Medical School, Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Melbourne, VIC, Australia.
| | - Lilith M Caballero-Aguilar
- The Graeme Clark Institute, The University of Melbourne, Parkville, Melbourne, VIC, Australia.
- Department of Biomedical Engineering, Faculty of Engineering and Information Technology, The University of Melbourne, Parkville, Melbourne, VIC, Australia.
- Aikenhead Centre for Medical Discovery, St. Vincent's Hospital, Melbourne, VIC, Australia.
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3
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Hetta HF, Elsaghir A, Sijercic VC, Akhtar MS, Gad SA, Moses A, Zeleke MS, Alanazi FE, Ahmed AK, Ramadan YN. Mesenchymal stem cell therapy in diabetic foot ulcer: An updated comprehensive review. Health Sci Rep 2024; 7:e2036. [PMID: 38650719 PMCID: PMC11033295 DOI: 10.1002/hsr2.2036] [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: 11/08/2023] [Revised: 02/06/2024] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Background Diabetes has evolved into a worldwide public health issue. One of the most serious complications of diabetes is diabetic foot ulcer (DFU), which frequently creates a significant financial strain on patients and lowers their quality of life. Up until now, there has been no curative therapy for DFU, only symptomatic relief or an interruption in the disease's progression. Recent studies have focused attention on mesenchymal stem cells (MSCs), which provide innovative and potential treatment candidates for several illnesses as they can differentiate into various cell types. They are mostly extracted from the placenta, adipose tissue, umbilical cord (UC), and bone marrow (BM). Regardless of their origin, they show comparable features and small deviations. Our goal is to investigate MSCs' therapeutic effects, application obstacles, and patient benefit strategies for DFU therapy. Methodology A comprehensive search was conducted using specific keywords relating to DFU, MSCs, and connected topics in the databases of Medline, Scopus, Web of Science, and PubMed. The main focus of the selection criteria was on English-language literature that explored the relationship between DFU, MSCs, and related factors. Results and Discussion Numerous studies are being conducted and have demonstrated that MSCs can induce re-epithelialization and angiogenesis, decrease inflammation, contribute to immunological modulation, and subsequently promote DFU healing, making them a promising approach to treating DFU. This review article provides a general snapshot of DFU (including clinical presentation, risk factors and etiopathogenesis, and conventional treatment) and discusses the clinical progress of MSCs in the management of DFU, taking into consideration the side effects and challenges during the application of MSCs and how to overcome these challenges to achieve maximum benefits. Conclusion The incorporation of MSCs in the management of DFU highlights their potential as a feasible therapeutic strategy. Establishing a comprehensive understanding of the complex relationship between DFU pathophysiology, MSC therapies, and related obstacles is essential for optimizing therapy outcomes and maximizing patient benefits.
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Affiliation(s)
- Helal F. Hetta
- Division of Microbiology, Immunology and Biotechnology, Department of Natural Products and Alternative MedicineFaculty of Pharmacy, University of TabukTabukSaudi Arabia
- Department of Medical Microbiology and ImmunologyFaculty of Medicine, Assiut UniversityAssiutEgypt
| | - Alaa Elsaghir
- Department of Microbiology and ImmunologyFaculty of Pharmacy, Assiut UniversityAssiutEgypt
| | | | | | - Sayed A. Gad
- Faculty of Medicine, Assiut UniversityAssiutEgypt
| | | | - Mahlet S. Zeleke
- Menelik II Medical and Health Science College, Kotebe Metropolitan UniversityAddis AbabaEthiopia
| | - Fawaz E. Alanazi
- Department of Pharmacology and ToxicologyFaculty of Pharmacy, University of TabukTabukSaudi Arabia
| | | | - Yasmin N. Ramadan
- Department of Microbiology and ImmunologyFaculty of Pharmacy, Assiut UniversityAssiutEgypt
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4
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Luo K, Wang L, Wang MX, Du R, Tang L, Yang KK, Wang YZ. 4D Printing of Biocompatible Scaffolds via In Situ Photo-crosslinking from Shape Memory Copolyesters. ACS APPLIED MATERIALS & INTERFACES 2023; 15:44373-44383. [PMID: 37669475 DOI: 10.1021/acsami.3c10747] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
The complexity of surgical treatments for large-area soft tissue injuries makes placing large implants into injury sites challenging. Aliphatic polyesters are often used for scaffold preparation in tissue engineering owing to their excellent biodegradability and biocompatibility. Scaffolds with shape-memory effect (SME) can also avoid large-volume trauma during the implantation. However, the complexity and diversity of diseases require more adaptable and precise processing methods. Four-dimensional (4D) printing, a booming smart material additive manufacturing technology, provides a new opportunity for developing shape memory scaffolds. With the aim of personalized or patient-adaptable soft tissues such as blood vessels, we developed a feasible strategy for fabricating scaffolds with fine architectures using 4D printing crosslinkable shape memory linear copolyesters using fused deposition modeling (FDM). To overcome the weak bonding strength of each printed layer during FDM, a catalyst-free photo-crosslinkable functional group derived from biocompatible cinnamic acid was embedded into the linear copolyesters as in situ crosslinking points during FDM printing. Under ultraviolet-assisted irradiation, the resulting 4D scaffold models demonstrated excellent SME, desirable mechanical performance, and good stability in a water environment owing to the chemical bonding between each layer. Moreover, the excellent biocompatibility of the scaffold was evaluated in vitro and in vivo. The developed composite scaffolds could be used for minimally invasive soft tissue repair.
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Affiliation(s)
- Kun Luo
- Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Li Wang
- Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China
- Department of Biomedical Engineering, School of Big Health and Intelligent Engineering, Chengdu 610500, China
| | - Man-Xi Wang
- Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Rui Du
- Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Li Tang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ke-Ke Yang
- Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Yu-Zhong Wang
- Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China
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5
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Scaffold-based delivery of mesenchymal stromal cells to diabetic wounds. Stem Cell Res Ther 2022; 13:426. [PMID: 35987712 PMCID: PMC9392335 DOI: 10.1186/s13287-022-03115-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 08/04/2022] [Indexed: 02/06/2023] Open
Abstract
AbstractFoot ulceration is a major complication of diabetes mellitus, which results in significant human suffering and a major burden on healthcare systems. The cause of impaired wound healing in diabetic patients is multifactorial with contributions from hyperglycaemia, impaired vascularization and neuropathy. Patients with non-healing diabetic ulcers may require amputation, creating an urgent need for new reparative treatments. Delivery of stem cells may be a promising approach to enhance wound healing because of their paracrine properties, including the secretion of angiogenic, immunomodulatory and anti-inflammatory factors. While a number of different cell types have been studied, the therapeutic use of mesenchymal stromal cells (MSCs) has been widely reported to improve delayed wound healing. However, topical administration of MSCs via direct injection has several disadvantages, including low cell viability and poor cell localization at the wound bed. To this end, various biomaterial conformations have emerged as MSC delivery vehicles to enhance cell viability and persistence at the site of implantation. This paper discusses biomaterial-based MSCs therapies in diabetic wound healing and highlights the low conversion rate to clinical trials and commercially available therapeutic products.
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6
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van Zuijlen PPM, Korkmaz HI, Sheraton VM, Haanstra TM, Pijpe A, de Vries A, van der Vlies CH, Bosma E, de Jong E, Middelkoop E, Vermolen FJ, Sloot PMA. The future of burn care from a complexity science perspective. J Burn Care Res 2022; 43:1312-1321. [PMID: 35267022 DOI: 10.1093/jbcr/irac029] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Healthcare is undergoing a profound technological and digital transformation and has become increasingly complex. It is important for burns professionals and researchers to adapt to these developments which may require new ways of thinking and subsequent new strategies. As Einstein has put it: 'We must learn to see the world anew'. The relatively new scientific discipline "Complexity science" can give more direction to this and is the metaphorical open door that should not go unnoticed in view of the burn care of the future. Complexity sciences studies 'why the whole is more than the sum of the parts'. It studies how multiple separate components interact with each other and their environment and how these interactions lead to 'behavior of the system'. Biological systems are always part of smaller and larger systems and exhibit the behavior of adaptivity, hence the name complex adaptive systems. From the perspective of complexity science, a severe burn injury is an extreme disruption of the 'human body system'. But this disruption also applies to the systems at the organ and cellular level. All these systems follow principles of complex systems. Awareness of the scaling process at multilevel helps to understand and manage the complex situation when dealing with severe burn cases. The aim of this paper is to create awareness of the concept of complexity and to demonstrate the value and possibilities of complexity science methods and tools for the future of burn care through examples from preclinical, clinical, and organizational perspective in burn care.
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Affiliation(s)
- Paul P M van Zuijlen
- Burn Center, Red Cross Hospital, Beverwijk, The Netherlands.,Department of Plastic and Reconstructive Surgery, Red Cross Hospital, Beverwijk, The Netherlands.,Department of Plastic Reconstructive and Hand Surgery, Amsterdam Movement Sciences (AMS) Institute, Amsterdam UMC, Location VUmc, Amsterdam, The Netherlands.,Paediatric Surgical Centre, Emma Children's Hospital, Amsterdam UMC, location AMC, Amsterdam, The Netherlands
| | - H Ibrahim Korkmaz
- Burn Center, Red Cross Hospital, Beverwijk, The Netherlands.,Department of Plastic Reconstructive and Hand Surgery, Amsterdam Movement Sciences (AMS) Institute, Amsterdam UMC, Location VUmc, Amsterdam, The Netherlands.,Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Location VUmc, Amsterdam, The Netherlands.,Association of Dutch Burn Centres (ADBC), Beverwijk, The Netherlands
| | - Vivek M Sheraton
- Institute for Advanced Study, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Anouk Pijpe
- Burn Center, Red Cross Hospital, Beverwijk, The Netherlands
| | - Annebeth de Vries
- Burn Center, Red Cross Hospital, Beverwijk, The Netherlands.,Paediatric Surgical Centre, Emma Children's Hospital, Amsterdam UMC, location AMC, Amsterdam, The Netherlands.,Department of Surgery, Red Cross Hospital, Beverwijk, The Netherlands
| | - Cornelis H van der Vlies
- Burn Centre, Maasstad Ziekenhuis, Rotterdam, The Netherlands.,Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Eelke Bosma
- Burn Centre and Department of Surgery, Martini Ziekenhuis, Groningen, The Netherlands
| | - Evelien de Jong
- Burn Center, Red Cross Hospital, Beverwijk, The Netherlands.,Intensive Care Unit, Red Cross Hospital, Beverwijk, The Netherlands
| | - Esther Middelkoop
- Burn Center, Red Cross Hospital, Beverwijk, The Netherlands.,Department of Plastic Reconstructive and Hand Surgery, Amsterdam Movement Sciences (AMS) Institute, Amsterdam UMC, Location VUmc, Amsterdam, The Netherlands.,Association of Dutch Burn Centres (ADBC), Beverwijk, The Netherlands
| | - Fred J Vermolen
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands.,Computational Mathematics, Hasselt University, Diepenbeek, Belgium
| | - Peter M A Sloot
- Institute for Advanced Study, University of Amsterdam, Amsterdam, The Netherlands.,Complexity Institute, Nanyang Technological University, Singapore.,ITMO University, Saint Petersburg, Russian Federation
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7
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Perikamana SKM, Seale N, Hoque J, Ryu JH, Kumar V, Shih YV, Varghese S. Molecularly Tailored Interface for Long-Term Xenogeneic Cell Transplantation. ADVANCED FUNCTIONAL MATERIALS 2022; 32:2108221. [PMID: 37920452 PMCID: PMC10622113 DOI: 10.1002/adfm.202108221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 11/04/2023]
Abstract
Encapsulation of therapeutic cells in a semipermeable device can mitigate the need for systemic immune suppression following cell transplantation by providing local immunoprotection while being permeable to nutrients, oxygen, and different cell-secreted biomolecules. However, fibrotic tissue deposition around the device has been shown to compromise the long-term function of the transplanted cells. Herein, a macroencapsulation device design that improves long-term survival and function of the transplanted cells is reported. The device is comprised of a semipermeable chitosan pouch with a tunable reservoir and molecularly engineered interface. The chitosan pouch interface decorated with 1,12-dodecanedioic acid (DDA), limits the cell adhesion and vigorous foreign body response while maintaining the barrier properties amenable to cell encapsulation. The device provides long-term protection to the encapsulated human primary hepatocytes in the subcutaneous space of immunocompetent mice. The device supports the encapsulated cells for up to 6 months as evident from cell viability and presence of human specific albumin in circulation. Solutions that integrate biomaterials and interfacial engineering such as the one described here may advance development of easy-to manufacture and retrievable devices for the transplantation of therapeutic cells in the absence of immunosuppression.
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Affiliation(s)
| | - Nailah Seale
- Department of Bioengineering University of California-San Diego La Jolla, CA 92093, USA
| | - Jiaul Hoque
- Department of Orthopaedic Surgery Duke University School of Medicine Durham, NC 27710, USA
| | - Ji Hyun Ryu
- Department of Orthopaedic Surgery Duke University School of Medicine Durham, NC 27710, USA
| | - Vardhman Kumar
- Department of Biomedical Engineering Duke University Durham, NC 27710, USA
| | - Yuru Vernon Shih
- Department of Orthopaedic Surgery Duke University School of Medicine Durham, NC 27710, USA
| | - Shyni Varghese
- Department of Orthopaedic Surgery Duke University School of Medicine Durham, NC 27710, USA
- Department of Biomedical Engineering Duke University Durham, NC 27710, USA
- Department of Mechanical Engineering and Materials Science Duke University Durham, NC 27710, USA
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8
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A 3D Mathematical Model of Coupled Stem Cell-Nutrient Dynamics in Myocardial Regeneration Therapy. J Theor Biol 2022; 537:111023. [PMID: 35041851 DOI: 10.1016/j.jtbi.2022.111023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/04/2021] [Accepted: 01/09/2022] [Indexed: 11/23/2022]
Abstract
Stem cell therapy is a promising treatment for the regeneration of myocardial tissue injured by an ischemic event. Mathematical modeling of myocardial regeneration via stem cell therapy is a challenging task, since the mechanisms underlying the processes involved in the treatment are not yet fully understood. Many aspects must be accounted for, such as the spread of stem cells and nutrients, chemoattraction, cell proliferation, stages of cell maturation, differentiation, angiogenesis, stochastic effects, just to name a few. In this paper we propose a 3D mathematical model with a free boundary that aims to provide a qualitative description of some main aspects of the stem cell regenerative therapy in a simplified scenario. The paper mainly focuses on the description of the shrinking of the necrotic core during treatment. The stem cell and nutrients dynamics are described through coupled reaction-diffusion problems. Proliferation, chemoattraction, tissue regeneration and nutrient consumption are included in the model.
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9
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Mavris SM, Hansen LM. Optimization of Oxygen Delivery Within Hydrogels. J Biomech Eng 2021; 143:101004. [PMID: 33973004 PMCID: PMC8299803 DOI: 10.1115/1.4051119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/05/2021] [Indexed: 12/19/2022]
Abstract
The field of tissue engineering has been continuously evolving since its inception over three decades ago with numerous new advancements in biomaterials and cell sources and widening applications to most tissues in the body. Despite the substantial promise and great opportunities for the advancement of current medical therapies and procedures, the field has yet to capture wide clinical translation due to some remaining challenges, including oxygen availability within constructs, both in vitro and in vivo. While this insufficiency of nutrients, specifically oxygen, is a limitation within the current frameworks of this field, the literature shows promise in new technological advances to efficiently provide adequate delivery of nutrients to cells. This review attempts to capture the most recent advances in the field of oxygen transport in hydrogel-based tissue engineering, including a comparison of current research as it pertains to the modeling, sensing, and optimization of oxygen within hydrogel constructs as well as new technological innovations to overcome traditional diffusion-based limitations. The application of these findings can further the advancement and development of better hydrogel-based tissue engineered constructs for future clinical translation and adoption.
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Affiliation(s)
- Sophia M. Mavris
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332
| | - Laura M. Hansen
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322
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10
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Coy R, Berg M, Phillips JB, Shipley RJ. Modelling-informed cell-seeded nerve repair construct designs for treating peripheral nerve injuries. PLoS Comput Biol 2021; 17:e1009142. [PMID: 34237052 PMCID: PMC8266098 DOI: 10.1371/journal.pcbi.1009142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 06/02/2021] [Indexed: 11/19/2022] Open
Abstract
Millions of people worldwide are affected by peripheral nerve injuries (PNI), involving billions of dollars in healthcare costs. Common outcomes for patients include paralysis and loss of sensation, often leading to lifelong pain and disability. Engineered Neural Tissue (EngNT) is being developed as an alternative to the current treatments for large-gap PNIs that show underwhelming functional recovery in many cases. EngNT repair constructs are composed of a stabilised hydrogel cylinder, surrounded by a sheath of material, to mimic the properties of nerve tissue. The technology also enables the spatial seeding of therapeutic cells in the hydrogel to promote nerve regeneration. The identification of mechanisms leading to maximal nerve regeneration and to functional recovery is a central challenge in the design of EngNT repair constructs. Using in vivo experiments in isolation is costly and time-consuming, offering a limited insight on the mechanisms underlying the performance of a given repair construct. To bridge this gap, we derive a cell-solute model and apply it to the case of EngNT repair constructs seeded with therapeutic cells which produce vascular endothelial growth factor (VEGF) under low oxygen conditions to promote vascularisation in the construct. The model comprises a set of coupled non-linear diffusion-reaction equations describing the evolving cell population along with its interactions with oxygen and VEGF fields during the first 24h after transplant into the nerve injury site. This model allows us to evaluate a wide range of repair construct designs (e.g. cell-seeding strategy, sheath material, culture conditions), the idea being that designs performing well over a short timescale could be shortlisted for in vivo trials. In particular, our results suggest that seeding cells beyond a certain density threshold is detrimental regardless of the situation considered, opening new avenues for future nerve tissue engineering.
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Affiliation(s)
- Rachel Coy
- Department of Mechanical Engineering, UCL, London, United Kingdom
- Center for Nerve Engineering, UCL, London, United Kingdom
| | - Maxime Berg
- Department of Mechanical Engineering, UCL, London, United Kingdom
- Center for Nerve Engineering, UCL, London, United Kingdom
- * E-mail:
| | - James B. Phillips
- Center for Nerve Engineering, UCL, London, United Kingdom
- Department of Pharmacology, School of Pharmacy, UCL, London, United Kingdom
| | - Rebecca J. Shipley
- Department of Mechanical Engineering, UCL, London, United Kingdom
- Center for Nerve Engineering, UCL, London, United Kingdom
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11
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Rothenbücher TSP, Gürbüz H, Pereira MP, Heiskanen A, Emneus J, Martinez-Serrano A. Next generation human brain models: engineered flat brain organoids featuring gyrification. Biofabrication 2021; 13:011001. [PMID: 33724233 DOI: 10.1088/1758-5090/abc95e] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Brain organoids are considered to be a highly promising in vitro model for the study of the human brain and, despite their various shortcomings, have already been used widely in neurobiological studies. Especially for drug screening applications, a highly reproducible protocol with simple tissue culture steps and consistent output, is required. Here we present an engineering approach that addresses several existing shortcomings of brain organoids. By culturing brain organoids with a polycaprolactone scaffold, we were able to modify their shape into a flat morphology. Engineered flat brain organoids (efBOs) possess advantageous diffusion conditions and thus their tissue is better supplied with oxygen and nutrients, preventing the formation of a necrotic tissue core. Moreover, the efBO protocol is highly simplified and allows to customize the organoid size directly from the start. By seeding cells onto 12 by 12 mm scaffolds, the brain organoid size can be significantly increased. In addition, we were able to observe folding reminiscent of gyrification around day 20, which was self-generated by the tissue. To our knowledge, this is the first study that reports intrinsically caused gyrification of neuronal tissue in vitro. We consider our efBO protocol as a next step towards the generation of a stable and reliable human brain model for drug screening applications and spatial patterning experiments.
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Affiliation(s)
- Theresa S P Rothenbücher
- Department of Molecular Biology, Autonomous University of Madrid, Center of Molecular Biology Severo Ochoa (CBMSO, UAM-CSIC), Madrid, Spain.,Shared first authorship
| | - Hakan Gürbüz
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark.,Felixrobotics BV, Utrecht, The Netherlands.,Shared first authorship
| | - Marta P Pereira
- Department of Molecular Biology, Autonomous University of Madrid, Center of Molecular Biology Severo Ochoa (CBMSO, UAM-CSIC), Madrid, Spain
| | - Arto Heiskanen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Jenny Emneus
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Alberto Martinez-Serrano
- Department of Molecular Biology, Autonomous University of Madrid, Center of Molecular Biology Severo Ochoa (CBMSO, UAM-CSIC), Madrid, Spain
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12
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Inlet flow rate of perfusion bioreactors affects fluid flow dynamics, but not oxygen concentration in 3D-printed scaffolds for bone tissue engineering: Computational analysis and experimental validation. Comput Biol Med 2020; 124:103826. [PMID: 32798924 DOI: 10.1016/j.compbiomed.2020.103826] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/15/2020] [Accepted: 05/15/2020] [Indexed: 02/08/2023]
Abstract
Fluid flow dynamics and oxygen-concentration in 3D-printed scaffolds within perfusion bioreactors are sensitive to controllable bioreactor parameters such as inlet flow rate. Here we aimed to determine fluid flow dynamics, oxygen-concentration, and cell proliferation and distribution in 3D-printed scaffolds as a result of different inlet flow rates of perfusion bioreactors using experiments and finite element modeling. Pre-osteoblasts were treated with 1 h pulsating fluid flow with low (0.8 Pa; PFFlow) or high peak shear stress (6.5 Pa; PFFhigh), and nitric oxide (NO) production was measured to validate shear stress sensitivity. Computational analysis was performed to determine fluid flow between 3D-scaffold-strands at three inlet flow rates (0.02, 0.1, 0.5 ml/min) during 5 days. MC3T3-E1 pre-osteoblast proliferation, matrix production, and oxygen-consumption in response to fluid flow in 3D-printed scaffolds inside a perfusion bioreactor were experimentally assessed. PFFhigh more strongly stimulated NO production by pre-osteoblasts than PFFlow. 3D-simulation demonstrated that dependent on inlet flow rate, fluid velocity reached a maximum (50-1200 μm/s) between scaffold-strands, and fluid shear stress (0.5-4 mPa) and wall shear stress (0.5-20 mPa) on scaffold-strands surfaces. At all inlet flow rates, gauge fluid pressure and oxygen-concentration were similar. The simulated cell proliferation and distribution, and oxygen-concentration data were in good agreement with the experimental results. In conclusion, varying a perfusion bioreactor's inlet flow rate locally affects fluid velocity, fluid shear stress, and wall shear stress inside 3D-printed scaffolds, but not gauge fluid pressure, and oxygen-concentration, which seems crucial for optimized bone tissue engineering strategies using bioreactors, scaffolds, and cells.
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13
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Zhao F, Lacroix D, Ito K, van Rietbergen B, Hofmann S. Changes in scaffold porosity during bone tissue engineering in perfusion bioreactors considerably affect cellular mechanical stimulation for mineralization. Bone Rep 2020; 12:100265. [PMID: 32613033 PMCID: PMC7315008 DOI: 10.1016/j.bonr.2020.100265] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/24/2020] [Accepted: 04/02/2020] [Indexed: 11/24/2022] Open
Abstract
Bone tissue engineering (BTE) experiments in vitro have shown that fluid-induced wall shear stress (WSS) can stimulate cells to produce mineralized extracellular matrix (ECM). The application of WSS on seeded cells can be achieved through bioreactors that perfuse medium through porous scaffolds. In BTE experiments in vitro, commonly a constant flow rate is used. Previous studies have found that tissue growth within the scaffold will result in an increase of the WSS over time. To keep the WSS in a reported optimal range of 10–30 mPa, the applied external flow rate can be decreased over time. To investigate what reduction of the external flow rate during culturing is needed to keep the WSS in the optimal range, we here conducted a computational study, which simulated the formation of ECM, and in which we investigated the effect of constant fluid flow and different fluid flow reduction scenarios on the WSS. It was found that for both constant and reduced fluid flow scenarios, the WSS did not exceed a critical value, which was set to 60 mPa. However, the constant flow velocity resulted in a reduction of the cell/ECM surface being exposed to a WSS in the optimal range from 50% at the start of culture to 18.6% at day 21. Reducing the fluid flow over time could avoid much of this effect, leaving the WSS in the optimal range for 40.9% of the surface at 21 days. Therefore, for achieving more mineralized tissue, the conventional manner of loading the perfusion bioreactors (i.e. constant flow rate/velocity) should be changed to a decreasing flow over time in BTE experiments. This study provides an in silico tool for finding the best fluid flow reduction strategy.
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Affiliation(s)
- Feihu Zhao
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, the Netherlands
- Zienkiewicz Centre for Computational Engineering (ZCCE), College of Engineering, Swansea University, SA1 8EN Swansea, United Kingdom
| | - Damien Lacroix
- INSIGNEO Institute for in silico Medicine, Department of Mechanical Engineering, University of Sheffield, S1 3JD Sheffield, United Kingdom
| | - Keita Ito
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, the Netherlands
| | - Bert van Rietbergen
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, the Netherlands
- Corresponding authors at: Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, the Netherlands.
| | - Sandra Hofmann
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, the Netherlands
- Corresponding authors at: Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, the Netherlands.
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14
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Coy R, Al-Badri G, Kayal C, O'Rourke C, Kingham PJ, Phillips JB, Shipley RJ. Combining in silico and in vitro models to inform cell seeding strategies in tissue engineering. J R Soc Interface 2020; 17:20190801. [PMID: 32208821 DOI: 10.1098/rsif.2019.0801] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The seeding density of therapeutic cells in engineered tissue impacts both cell survival and vascularization. Excessively high seeded cell densities can result in increased death and thus waste of valuable cells, whereas lower seeded cell densities may not provide sufficient support for the tissue in vivo, reducing efficacy. Additionally, the production of growth factors by therapeutic cells in low oxygen environments offers a way of generating growth factor gradients, which are important for vascularization, but hypoxia can also induce unwanted levels of cell death. This is a complex problem that lends itself to a combination of computational modelling and experimentation. Here, we present a spatio-temporal mathematical model parametrized using in vitro data capable of simulating the interactions between a therapeutic cell population, oxygen concentrations and vascular endothelial growth factor (VEGF) concentrations in engineered tissues. Simulations of collagen nerve repair constructs suggest that specific seeded cell densities and non-uniform spatial distributions of seeded cells could enhance cell survival and the generation of VEGF gradients. These predictions can now be tested using targeted experiments.
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Affiliation(s)
- R Coy
- CoMPLEX, University College London, London, UK.,UCL Centre for Nerve Engineering, University College London, London, UK
| | - G Al-Badri
- UCL Centre for Nerve Engineering, University College London, London, UK.,Department of Mathematics, University College London, London, UK
| | - C Kayal
- UCL Centre for Nerve Engineering, University College London, London, UK.,Department of Mechanical Engineering, University College London, London, UK
| | - C O'Rourke
- UCL Centre for Nerve Engineering, University College London, London, UK.,Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK
| | - P J Kingham
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - J B Phillips
- UCL Centre for Nerve Engineering, University College London, London, UK.,Department of Pharmacology, UCL School of Pharmacy, University College London, London, UK
| | - R J Shipley
- UCL Centre for Nerve Engineering, University College London, London, UK.,Department of Mechanical Engineering, University College London, London, UK
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15
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Wagner K, Girardo S, Goswami R, Rosso G, Ulbricht E, Müller P, Soteriou D, Träber N, Guck J. Colloidal crystals of compliant microgel beads to study cell migration and mechanosensitivity in 3D. SOFT MATTER 2019; 15:9776-9787. [PMID: 31742293 DOI: 10.1039/c9sm01226e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tissues are defined not only by their biochemical composition, but also by their distinct mechanical properties. It is now widely accepted that cells sense their mechanical environment and respond to it. However, studying the effects of mechanics in in vitro 3D environments is challenging since current 3D hydrogel assays convolve mechanics with gel porosity and adhesion. Here, we present novel colloidal crystals as modular 3D scaffolds where these parameters are principally decoupled by using monodisperse, protein-coated PAAm microgel beads as building blocks, so that variable stiffness regions can be achieved within one 3D colloidal crystal. Characterization of the colloidal crystal and oxygen diffusion simulations suggested the suitability of the scaffold to support cell survival and growth. This was confirmed by live-cell imaging and fibroblast culture over a period of four days. Moreover, we demonstrate unambiguous durotactic fibroblast migration and mechanosensitive neurite outgrowth of dorsal root ganglion neurons in 3D. This modular approach of assembling 3D scaffolds from mechanically and biochemically well-defined building blocks allows the spatial patterning of stiffness decoupled from porosity and adhesion sites in principle and provides a platform to investigate mechanosensitivity in 3D environments approximating tissues in vitro.
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Affiliation(s)
- Katrin Wagner
- Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
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16
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Sämfors S, Karlsson K, Sundberg J, Markstedt K, Gatenholm P. Biofabrication of bacterial nanocellulose scaffolds with complex vascular structure. Biofabrication 2019; 11:045010. [DOI: 10.1088/1758-5090/ab2b4f] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Elsayed Y, Lekakou C, Tomlins P. Modeling, simulations, and optimization of smooth muscle cell tissue engineering for the production of vascular grafts. Biotechnol Bioeng 2019; 116:1509-1522. [PMID: 30737955 DOI: 10.1002/bit.26955] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 12/20/2022]
Abstract
The paper presents a transient, continuum, two-phase model of the tissue engineering in fibrous scaffolds, including transport equations for the flowing culture medium, nutrient and cell concentration with transverse and in-plane diffusion and cell migration, a novel feature of local in-plane transport across a phenomenological pore and innovative layer-by-layer cell filling approach. The model is successfully validated for the smooth muscle cell tissue engineering of a vascular graft using crosslinked, electrospun gelatin fiber scaffolds for both static and dynamic cell culture, the latter in a dynamic bioreactor with a rotating shaft on which the tubular scaffold is attached. Parametric studies evaluate the impact of the scaffold microstructure, cell dynamics, oxygen transport, and static or dynamic conditions on the rate and extent of cell proliferation and depth of oxygen accessibility. An optimized scaffold of 75% dry porosity is proposed that can be tissue engineered into a viable and still fully oxygenated graft of the tunica media of the coronary artery within 2 days in the dynamic bioreactor. Such scaffold also matches the mechanical properties of the tunica media of the human coronary artery and the suture retention strength of a saphenous vein, often used as a coronary artery graft.
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Affiliation(s)
- Yahya Elsayed
- Department of Mechanical Engineering Sciences, Engineering Materials Centre, University of Surrey, Guildford, Surrey, UK.,Department of Mechanical Engineering Sciences, Centre of Biomedical Engineering, University of Surrey, Guildford, Surrey, UK
| | - Constantina Lekakou
- Department of Mechanical Engineering Sciences, Engineering Materials Centre, University of Surrey, Guildford, Surrey, UK
| | - Paul Tomlins
- National Physical Laboratory, Teddington, Middlesex, UK
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18
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Jover E, Fagnano M, Angelini G, Madeddu P. Cell Sources for Tissue Engineering Strategies to Treat Calcific Valve Disease. Front Cardiovasc Med 2018; 5:155. [PMID: 30460245 PMCID: PMC6232262 DOI: 10.3389/fcvm.2018.00155] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 10/10/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiovascular calcification is an independent risk factor and an established predictor of adverse cardiovascular events. Despite concomitant factors leading to atherosclerosis and heart valve disease (VHD), the latter has been identified as an independent pathological entity. Calcific aortic valve stenosis is the most common form of VDH resulting of either congenital malformations or senile “degeneration.” About 2% of the population over 65 years is affected by aortic valve stenosis which represents a major cause of morbidity and mortality in the elderly. A multifactorial, complex and active heterotopic bone-like formation process, including extracellular matrix remodeling, osteogenesis and angiogenesis, drives heart valve “degeneration” and calcification, finally causing left ventricle outflow obstruction. Surgical heart valve replacement is the current therapeutic option for those patients diagnosed with severe VHD representing more than 20% of all cardiac surgeries nowadays. Tissue Engineering of Heart Valves (TEHV) is emerging as a valuable alternative for definitive treatment of VHD and promises to overcome either the chronic oral anticoagulation or the time-dependent deterioration and reintervention of current mechanical or biological prosthesis, respectively. Among the plethora of approaches and stablished techniques for TEHV, utilization of different cell sources may confer of additional properties, desirable and not, which need to be considered before moving from the bench to the bedside. This review aims to provide a critical appraisal of current knowledge about calcific VHD and to discuss the pros and cons of the main cell sources tested in studies addressing in vitro TEHV.
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Affiliation(s)
- Eva Jover
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Marco Fagnano
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Gianni Angelini
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Paolo Madeddu
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
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19
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Paim Á, Tessaro IC, Pranke P, Cardozo NSM. A sensitivity analysis for tissue development by varying model parameters and input variables. CAN J CHEM ENG 2018. [DOI: 10.1002/cjce.23171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ágata Paim
- Department of Chemical Engineering; Universidade Federal do Rio Grande do Sul (UFRGS), R. Eng. Luis Englert; s/n. Porto Alegre Rio Grande do Sul 90040-040 Brazil
| | - Isabel C. Tessaro
- Department of Chemical Engineering; Universidade Federal do Rio Grande do Sul (UFRGS), R. Eng. Luis Englert; s/n. Porto Alegre Rio Grande do Sul 90040-040 Brazil
| | - Patricia Pranke
- Faculty of Pharmacy; Universidade Federal do Rio Grande do Sul (UFRGS); Av. Ipiranga, 2752. Porto Alegre Rio Grande do Sul 90610-000 Brazil
- Stem Cell Research Institute; Porto Alegre; Rio Grande do Sul Brazil
| | - Nilo S. M. Cardozo
- Department of Chemical Engineering; Universidade Federal do Rio Grande do Sul (UFRGS), R. Eng. Luis Englert; s/n. Porto Alegre Rio Grande do Sul 90040-040 Brazil
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20
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Development of human-derived hemoglobin–albumin microspheres as oxygen carriers using Shirasu porous glass membrane emulsification. J Biosci Bioeng 2018; 126:533-539. [DOI: 10.1016/j.jbiosc.2018.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/20/2018] [Accepted: 04/25/2018] [Indexed: 12/18/2022]
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21
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Numerical optimization of cell colonization modelling inside scaffold for perfusion bioreactor: A multiscale model. Med Eng Phys 2018; 57:40-50. [PMID: 29753628 DOI: 10.1016/j.medengphy.2018.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 04/11/2018] [Accepted: 04/30/2018] [Indexed: 12/18/2022]
Abstract
Part of clinically applicable bone graft substitutes are developed by using mechanical stimulation of flow-perfusion into cell-seeded scaffolds. The role of fluid flow is crucial in driving the nutrient to seeded cells and in stimulating cell colonization. A common numerical approach is to use a multiscale model to link some physical quantities (wall shear stress and inlet flow rate) that act at different scales. In this study, a multiscale model is developed in order to determine the optimal inlet flow rate to cultivate osteoblast-like cells seeded in a controlled macroporous biomaterial inside a perfusion bioreactor system. We focus particularly on the influence of Wall Shear Stress on cell colonization to predict cell colonization at the macroscale. Results obtained at the microscale are interpolated at the macroscale to determine the optimal flow rate. For a macroporous scaffold made of interconnected pores with pore diameters of above 350 μm and interconnection diameters of 150 μm, the model predicts a cell colonization of 325% after a 7-day-cell culture with a constant inlet flow rate of 0.69 mL·min-1. Furthermore, the strength of this protocol is the possibility to adapt it to most porous biomaterials and dynamic cell culture systems.
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22
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Paim Á, Cardozo NSM, Tessaro IC, Pranke P. Relevant biological processes for tissue development with stem cells and their mechanistic modeling: A review. Math Biosci 2018; 301:147-158. [PMID: 29746816 DOI: 10.1016/j.mbs.2018.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 04/27/2018] [Accepted: 05/04/2018] [Indexed: 02/07/2023]
Abstract
A potential alternative for tissue transplants is tissue engineering, in which the interaction of cells and biomaterials can be optimized. Tissue development in vitro depends on the complex interaction of several biological processes such as extracellular matrix synthesis, vascularization and cell proliferation, adhesion, migration, death, and differentiation. The complexity of an individual phenomenon or of the combination of these processes can be studied with phenomenological modeling techniques. This work reviews the main biological phenomena in tissue development and their mathematical modeling, focusing on mesenchymal stem cell growth in three-dimensional scaffolds.
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Affiliation(s)
- Ágata Paim
- Department of Chemical Engineering, Universidade Federal do Rio Grande do Sul (UFRGS), R. Eng. Luis Englert, s/n Porto Alegre, Rio Grande do Sul 90040-040, Brazil; Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752. Porto Alegre, Rio Grande do Sul 90610-000, Brazil.
| | - Nilo S M Cardozo
- Department of Chemical Engineering, Universidade Federal do Rio Grande do Sul (UFRGS), R. Eng. Luis Englert, s/n Porto Alegre, Rio Grande do Sul 90040-040, Brazil
| | - Isabel C Tessaro
- Department of Chemical Engineering, Universidade Federal do Rio Grande do Sul (UFRGS), R. Eng. Luis Englert, s/n Porto Alegre, Rio Grande do Sul 90040-040, Brazil
| | - Patricia Pranke
- Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752. Porto Alegre, Rio Grande do Sul 90610-000, Brazil; Stem Cell Research Institute, Porto Alegre, Rio Grande do Sul, Brazil
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23
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A perspective on the physical, mechanical and biological specifications of bioinks and the development of functional tissues in 3D bioprinting. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.bprint.2018.02.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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24
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Latifi N, Asgari M, Vali H, Mongeau L. A tissue-mimetic nano-fibrillar hybrid injectable hydrogel for potential soft tissue engineering applications. Sci Rep 2018; 8:1047. [PMID: 29348423 PMCID: PMC5773686 DOI: 10.1038/s41598-017-18523-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/13/2017] [Indexed: 01/19/2023] Open
Abstract
While collagen type I (Col-I) is commonly used as a structural component of biomaterials, collagen type III (Col-III), another fibril forming collagen ubiquitous in many soft tissues, has not previously been used. In the present study, the novel concept of an injectable hydrogel with semi-interpenetrating polymeric networks of heterotypic collagen fibrils, with tissue-specific Col-III to Col-I ratios, in a glycol-chitosan matrix was investigated. Col-III was introduced as a component of the novel hydrogel, inspired by its co-presence with Col-I in many soft tissues, its influence on the Col-I fibrillogenesis in terms of diameter and mechanics, and its established role in regulating scar formation. The hydrogel has a nano-fibrillar porous structure, and is mechanically stable under continuous dynamic stimulation. It was found to provide a longer half-life of about 35 days than similar hyaluronic acid-based hydrogels, and to support cell implantation in terms of viability, metabolic activity, adhesion and migration. The specific case of pure Col-III fibrils in a glycol-chitosan matrix was investigated. The proposed hydrogels meet many essential requirements for soft tissue engineering applications, particularly for mechanically challenged tissues such as vocal folds and heart valves.
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Affiliation(s)
- Neda Latifi
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke street west, Montreal, QC H3A 0C3, Canada.
| | - Meisam Asgari
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke street west, Montreal, QC H3A 0C3, Canada
| | - Hojatollah Vali
- Department of Anatomy & Cell Biology, McGill University, 3640 University street, Montreal, QC H3A 2B2, Canada
| | - Luc Mongeau
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke street west, Montreal, QC H3A 0C3, Canada
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25
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González-Valverde I, Semino C, García-Aznar JM. Phenomenological modelling and simulation of cell clusters in 3D cultures. Comput Biol Med 2016; 77:249-60. [PMID: 27615191 DOI: 10.1016/j.compbiomed.2016.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 08/30/2016] [Accepted: 08/30/2016] [Indexed: 02/04/2023]
Abstract
Cell clustering and aggregation are fundamental processes in the development of several tissues and the progression of many diseases. The formation of these aggregates also has a direct impact on the oxygen concentration in their surroundings due to cellular respiration and poor oxygen diffusion through clusters. In this work, we propose a mathematical model that is capable of simulating cell cluster formation in 3D cultures through combining a particle-based and a finite element approach to recreate complex experimental conditions. Cells are modelled considering cell proliferation, cell death and cell-cell mechanical interactions. Additionally, the oxygen concentration profile is calculated through finite element analysis using a reaction-diffusion model that considers cell oxygen consumption and diffusion through the extracellular matrix and the cell clusters. In our model, the local oxygen concentration in the medium determines both cell proliferation and cell death. Numerical predictions are also compared with experimental data from the literature. The simulation results indicate that our model can predict cell clustering, cluster growth and oxygen distribution in 3D cultures. We conclude that the initial cell distribution, cell death and cell proliferation dynamics determine the size and density of clusters. Moreover, these phenomena are directly affected by the oxygen transport in the 3D culture.
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Affiliation(s)
- I González-Valverde
- Universidad de Zaragoza, Aragón Institute of Engineering Research (I3A), Department of Mechanical Engineering, Campus Rio Ebro, 50018 Zaragoza, Spain; Instituto Químico Sarrià, Universidad Ramon Llul, Via Augusta, 390, 08017 Barcelona, Spain
| | - C Semino
- Instituto Químico Sarrià, Universidad Ramon Llul, Via Augusta, 390, 08017 Barcelona, Spain
| | - J M García-Aznar
- Universidad de Zaragoza, Aragón Institute of Engineering Research (I3A), Department of Mechanical Engineering, Campus Rio Ebro, 50018 Zaragoza, Spain.
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26
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Mokhtari-Jafari F, Amoabediny G, Haghighipour N, Zarghami R, Saatchi A, Akbari J, Salehi-Nik N. Mathematical modeling of cell growth in a 3D scaffold and validation of static and dynamic cultures. Eng Life Sci 2016. [DOI: 10.1002/elsc.201500047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Fatemeh Mokhtari-Jafari
- School of Chemical Engineering; College of Engineering; University of Tehran; Tehran Iran
- Department of Biomedical Engineering; Research Center for New Technologies in Life Science Engineering; University of Tehran; Tehran Iran
- National Cell Bank of Iran; Pasteur Institute of Iran; Tehran Iran
| | - Ghassem Amoabediny
- School of Chemical Engineering; College of Engineering; University of Tehran; Tehran Iran
- Department of Biomedical Engineering; Research Center for New Technologies in Life Science Engineering; University of Tehran; Tehran Iran
| | | | - Reza Zarghami
- School of Chemical Engineering; College of Engineering; University of Tehran; Tehran Iran
| | - Alireza Saatchi
- School of Chemical Engineering; College of Engineering; University of Tehran; Tehran Iran
- Department of Biomedical Engineering; Research Center for New Technologies in Life Science Engineering; University of Tehran; Tehran Iran
| | - Javad Akbari
- School of Chemical Engineering; College of Engineering; University of Tehran; Tehran Iran
- Department of Biomedical Engineering; Research Center for New Technologies in Life Science Engineering; University of Tehran; Tehran Iran
| | - Nasim Salehi-Nik
- School of Chemical Engineering; College of Engineering; University of Tehran; Tehran Iran
- Department of Biomedical Engineering; Research Center for New Technologies in Life Science Engineering; University of Tehran; Tehran Iran
- National Cell Bank of Iran; Pasteur Institute of Iran; Tehran Iran
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27
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Li E, Chang CC, Zhang Z, Li Q. Characterization of tissue scaffolds for time-dependent biotransport criteria - a novel computational procedure. Comput Methods Biomech Biomed Engin 2015; 19:1210-24. [PMID: 26718135 DOI: 10.1080/10255842.2015.1124268] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study aims to establish a new computational framework that allows modeling transient oxygen diffusion in tissue scaffolds more efficiently. It has been well known that the survival of cells strongly relies on continuous oxygen/nutrient supply and metabolite removal. With optimal design in scaffold architecture, its ability to sustain long distance oxygen supply could be improved considerably. In this study, finite element based homogenization procedure is first used to characterize the initial effective biotransport properties in silico. These initial properties are proper indicators to prediction of the on-going performance of tissue scaffolds over time. The transient model by adopting an edge-based smoothed finite element method with combination of mass-redistributed method is then established to more efficiently simulate the transient oxygen transfer process in tissue scaffolds. The proposed new method allows large time steps to model the oxygen diffusion process without losing numerical accuracy, thereby enhancing the computational efficiency significantly, in particular for the design optimization problems which typically require numerous analysis iterations. A number of different scaffold designs are examined either under net diffusion without cell seeding, or under cellular oxygen/nutrient uptake with or without considering cell viability. The association between the homogenized effective diffusivity of net scaffold microstructures and corresponding transient diffusion and time-dependent cellular activities is divulged. This study provides some insights into scaffold design.
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Affiliation(s)
- Eric Li
- a School of Aerospace, Mechanical and Mechatronic Engineering , The University of Sydney , Sydney , Australia
| | - C C Chang
- a School of Aerospace, Mechanical and Mechatronic Engineering , The University of Sydney , Sydney , Australia
| | - Zhongpu Zhang
- a School of Aerospace, Mechanical and Mechatronic Engineering , The University of Sydney , Sydney , Australia
| | - Qing Li
- a School of Aerospace, Mechanical and Mechatronic Engineering , The University of Sydney , Sydney , Australia
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Cellular Nutrition in Complex Three-Dimensional Scaffolds: A Comparison between Experiments and Computer Simulations. Int J Biomater 2015; 2015:584362. [PMID: 26539216 PMCID: PMC4619933 DOI: 10.1155/2015/584362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/30/2015] [Indexed: 12/22/2022] Open
Abstract
Studies on bone cell ingrowth into synthetic, porous three-dimensional (3D) implants showed difficulties arising from impaired cellular proliferation and differentiation in the core region of these scaffolds with increasing scaffold volume in vitro. Therefore, we developed an in vitro perfusion cell culture module, which allows the analysis of cells in the interior of scaffolds under different medium flow rates. For each flow rate the cell viability was measured and compared with results from computer simulations that predict the local oxygen supply and shear stress inside the scaffold based on the finite element method. We found that the local cell viability correlates with the local oxygen concentration and the local shear stress. On the one hand the oxygen supply of the cells in the core becomes optimal with a higher perfusion flow. On the other hand shear stress caused by high flow rates impedes cell vitality, especially at the surface of the scaffold. Our results demonstrate that both parameters must be considered to derive an optimal nutrient flow rate.
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29
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Narayanan LK, Kumar A, Tan Z(G, Bernacki S, Starly B, Shirwaiker RA. Alginate Microspheroid Encapsulation and Delivery of MG-63 Cells Into Polycaprolactone Scaffolds: A New Biofabrication Approach for Tissue Engineering Constructs. J Nanotechnol Eng Med 2015. [DOI: 10.1115/1.4031174] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Scaffolds play an important role in tissue engineering by providing structural framework and a surface for cells to attach, proliferate, and secrete extracellular matrix (ECM). In order to enable efficient tissue formation, delivering sufficient cells into the scaffold three-dimensional (3D) matrix using traditional static and dynamic seeding methods continues to be a critical challenge. In this study, we investigate a new cell delivery approach utilizing deposition of hydrogel-cell encapsulated microspheroids into polycaprolactone (PCL) scaffolds to improve the seeding efficiency. Three-dimensional-bioplotted PCL constructs (0 deg/90 deg lay down, 284 ± 6 μm strand width, and 555 ± 8 μm strand separation) inoculated with MG-63 model bone cells encapsulated within electrostatically generated calcium-alginate microspheroids (Ø 405 ± 13 μm) were evaluated over seven days in static culture. The microspheroids were observed to be uniformly distributed throughout the PCL scaffold cross section. Encapsulated cells remained viable within the constructs over the test interval with the highest proliferation noted at day 4. This study demonstrates the feasibility of the new approach and highlights the role and critical challenges to be addressed to successfully utilize 3D-bioprinting for microencapsulated cell delivery.
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Affiliation(s)
- Lokesh K. Narayanan
- Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, Raleigh, NC 27616 e-mail:
| | - Arun Kumar
- Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, Raleigh, NC 27616 e-mail:
| | - Zhuo (George) Tan
- Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, Raleigh, NC 27616 e-mail:
| | - Susan Bernacki
- UNC/NCSU Joint Department of Biomedical Engineering, North Carolina State University, 4102C Engineering Building III, Raleigh, NC 27616 e-mail:
| | - Binil Starly
- Edward P. Fitts Department of Industrial and Systems Engineering; UNC/NCSU Joint Department of Biomedical Engineering, North Carolina State University, 400 Daniels Hall, Raleigh, NC 27616 e-mail:
| | - Rohan A. Shirwaiker
- Edward P. Fitts Department of Industrial and Systems Engineering; UNC/NCSU Joint Department of Biomedical Engineering, North Carolina State University, 400 Daniels Hall, Raleigh, NC 27616 e-mail:
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30
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Armstrong JPK, Shakur R, Horne JP, Dickinson SC, Armstrong CT, Lau K, Kadiwala J, Lowe R, Seddon A, Mann S, Anderson JLR, Perriman AW, Hollander AP. Artificial membrane-binding proteins stimulate oxygenation of stem cells during engineering of large cartilage tissue. Nat Commun 2015; 6:7405. [PMID: 26080734 PMCID: PMC4557285 DOI: 10.1038/ncomms8405] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/06/2015] [Indexed: 01/08/2023] Open
Abstract
Restricted oxygen diffusion can result in central cell necrosis in engineered tissue, a problem that is exacerbated when engineering large tissue constructs for clinical application. Here we show that pre-treating human mesenchymal stem cells (hMSCs) with synthetic membrane-active myoglobin-polymer–surfactant complexes can provide a reservoir of oxygen capable of alleviating necrosis at the centre of hyaline cartilage. This is achieved through the development of a new cell functionalization methodology based on polymer–surfactant conjugation, which allows the delivery of functional proteins to the hMSC membrane. This new approach circumvents the need for cell surface engineering using protein chimerization or genetic transfection, and we demonstrate that the surface-modified hMSCs retain their ability to proliferate and to undergo multilineage differentiation. The functionalization technology is facile, versatile and non-disruptive, and in addition to tissue oxygenation, it should have far-reaching application in a host of tissue engineering and cell-based therapies. Avoiding central cell necrosis at the centre of large engineered tissue constructs is an important issue for in vitro tissue engineering. Here, the authors demonstrate that this problem may be overcome by oxygenating human mesenchymal stem cells with artificial membrane-binding proteins.
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Affiliation(s)
- James P K Armstrong
- Bristol Centre for Functional Nanomaterials, University of Bristol, Bristol BS8 1FD, UK.,Centre for Organized Matter Chemistry and Centre for Protolife Research, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.,School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK
| | - Rameen Shakur
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK.,Laboratory for Regenerative Medicine, Department of Surgery, School of Clinical Medicine, University of Cambridge, Cambridge CB2 OQQ, UK.,School of Dentistry and Medicine, University of Central Lancashire, Fylde Road, Preston PR1 2HE, UK
| | - Joseph P Horne
- School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK
| | - Sally C Dickinson
- School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK
| | | | - Katherine Lau
- Renishaw plc, Spectroscopy Products Division, Wotton-Under-Edge GL12 7DW, UK
| | - Juned Kadiwala
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK.,Laboratory for Regenerative Medicine, Department of Surgery, School of Clinical Medicine, University of Cambridge, Cambridge CB2 OQQ, UK
| | - Robert Lowe
- The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Annela Seddon
- Bristol Centre for Functional Nanomaterials, University of Bristol, Bristol BS8 1FD, UK.,HH Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK
| | - Stephen Mann
- Centre for Organized Matter Chemistry and Centre for Protolife Research, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | | | - Adam W Perriman
- Centre for Organized Matter Chemistry and Centre for Protolife Research, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.,School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK
| | - Anthony P Hollander
- School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK.,Present address: Institute of Integrative Biology, Biosciences Building, University of Liverpool, Liverpool L69 7ZB, UK
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31
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Cook CA, Hahn KC, Morrissette-McAlmon JBF, Grayson WL. Oxygen delivery from hyperbarically loaded microtanks extends cell viability in anoxic environments. Biomaterials 2015; 52:376-84. [PMID: 25818444 PMCID: PMC4955786 DOI: 10.1016/j.biomaterials.2015.02.036] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 02/01/2015] [Accepted: 02/06/2015] [Indexed: 11/15/2022]
Abstract
Oxygen diffusion limitations within nascent tissue engineered (TE) grafts lead to the development of hypoxic regions, cell death, and graft failure. Previous efforts have been made to deliver oxygen within TE scaffolds, including peroxide-doping, perfluorocarbons, and hyperbaric oxygen therapy, to mitigate these effects and help maintain post transplantation cell viability, but these have suffered from significant drawbacks. Here we present a novel approach utilizing polymeric hollow-core microspheres that can be hyperbarically loaded with oxygen and subsequently provide prolonged oxygen delivery. These oxygen carriers are termed, microtanks. With an interest in orthopedic applications, we combined microtanks within polycaprolactone to form solid phase constructs with oxygen delivery capabilities. The mathematical laws governing oxygen delivery from microtank-loaded constructs are developed along with empirical validation. Constructs achieved periods of oxygen delivery out to 6 days, which was shown to prolong the survival of human adipose derived stem cells (hASCs) and human umbilical vein endothelial cells (HUVECs) as well as to enhance their cellular morphology under anoxic conditions. The results of this study suggest the microtank approach may be a feasible means of maintaining cell viability in TE scaffolds during the critical period of vascularization in vivo.
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Affiliation(s)
- Colin A Cook
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kathryn C Hahn
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Justin B F Morrissette-McAlmon
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Warren L Grayson
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Material Sciences & Engineering, Johns Hopkins University, School of Engineering, Baltimore, MD, USA.
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32
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Fiedler T, Belova IV, Murch GE, Poologasundarampillai G, Jones JR, Roether JA, Boccaccini AR. A comparative study of oxygen diffusion in tissue engineering scaffolds. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:2573-2578. [PMID: 25016936 DOI: 10.1007/s10856-014-5264-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 06/19/2014] [Indexed: 06/03/2023]
Abstract
Tissue engineering scaffolds are designed to support tissue self-healing within physiological environments by promoting the attachment, growth and differentiation of relevant cells. Newly formed tissue must be supplied with sufficient levels of oxygen to prevent necrosis. Oxygen diffusion is the major transport mechanism before vascularization is completed and oxygen is predominantly supplied via blood vessels. The present study compares different designs for scaffolds in the context of their oxygen diffusion ability. In all cases, oxygen diffusion is confined to the scaffold pores that are assumed to be completely occupied by newly formed tissue. The solid phase of the scaffolds acts as diffusion barrier that locally inhibits oxygen diffusion, i.e. no oxygen passes through the scaffold material. As a result, the oxygen diffusivity is determined by the scaffold porosity and pore architecture. Lattice Monte Carlo simulations are performed to compare the normalized oxygen diffusivities in scaffolds obtained by the foam replication (FR) method, robocasting and sol-gel foaming. Scaffolds made by the FR method were found to have the highest oxygen diffusivity due to their high porosity and interconnected pores. These structures enable the best oxygen supply for newly formed tissue among the scaffold types considered according to the present numerical predictions.
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Affiliation(s)
- T Fiedler
- School of Engineering, The University of Newcastle, Callaghan, NSW 2287, Australia,
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33
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Hypoxic signaling during tissue repair and regenerative medicine. Int J Mol Sci 2014; 15:19791-815. [PMID: 25365172 PMCID: PMC4264139 DOI: 10.3390/ijms151119791] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/12/2014] [Accepted: 10/15/2014] [Indexed: 12/11/2022] Open
Abstract
In patients with chronic wounds, autologous tissue repair is often not sufficient to heal the wound. These patients might benefit from regenerative medicine or the implantation of a tissue-engineered scaffold. Both wound healing and tissue engineering is dependent on the formation of a microvascular network. This process is highly regulated by hypoxia and the transcription factors hypoxia-inducible factors-1α (HIF-1α) and -2α (HIF-2α). Even though much is known about the function of HIF-1α in wound healing, knowledge about the function of HIF-2α in wound healing is lacking. This review focuses on the function of HIF-1α and HIF-2α in microvascular network formation, wound healing, and therapy strategies.
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34
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Khouri RK, Khouri RER, Lujan-Hernandez JR, Khouri KR, Lancerotto L, Orgill DP. Diffusion and perfusion: the keys to fat grafting. Plast Reconstr Surg Glob Open 2014; 2:e220. [PMID: 25426403 PMCID: PMC4229279 DOI: 10.1097/gox.0000000000000183] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/22/2014] [Indexed: 01/06/2023]
Abstract
BACKGROUND Fat grafting is now widely used in plastic surgery. Long-term graft retention can be unpredictable. Fat grafts must obtain oxygen via diffusion until neovascularization occurs, so oxygen delivery may be the overarching variable in graft retention. METHODS We studied the peer-reviewed literature to determine which aspects of a fat graft and the microenvironment surrounding a fat graft affect oxygen delivery and created 3 models relating distinct variables to oxygen delivery and graft retention. RESULTS Our models confirm that thin microribbons of fat maximize oxygen transport when injected into a large, compliant, well-vascularized recipient site. The "Microribbon Model" predicts that, in a typical human, fat injections larger than 0.16 cm in radius will have a region of central necrosis. Our "Fluid Accommodation Model" predicts that once grafted tissues approach a critical interstitial fluid pressure of 9 mm Hg, any additional fluid will drastically increase interstitial fluid pressure and reduce capillary perfusion and oxygen delivery. Our "External Volume Expansion Effect Model" predicts the effect of vascular changes induced by preoperative external volume expansion that allow for greater volumes of fat to be successfully grafted. CONCLUSIONS These models confirm that initial fat grafting survival is limited by oxygen diffusion. Preoperative expansion increases oxygen diffusion capacity allowing for additional graft retention. These models provide a scientific framework for testing the current fat grafting theories.
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Affiliation(s)
- Roger K Khouri
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Mass.; University of Michigan Medical School, Ann Arbor, Mich.; Gulliver Preparatory School, Pinecrest, Fla.; College of Engineering, Boston University, Boston, Mass.; Institute of Plastic Reconstructive and Aesthetic Surgery, University of Padova, Padova, Italy; and Harvard Medical School, Boston, Mass
| | - Raoul-Emil R Khouri
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Mass.; University of Michigan Medical School, Ann Arbor, Mich.; Gulliver Preparatory School, Pinecrest, Fla.; College of Engineering, Boston University, Boston, Mass.; Institute of Plastic Reconstructive and Aesthetic Surgery, University of Padova, Padova, Italy; and Harvard Medical School, Boston, Mass
| | - Jorge R Lujan-Hernandez
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Mass.; University of Michigan Medical School, Ann Arbor, Mich.; Gulliver Preparatory School, Pinecrest, Fla.; College of Engineering, Boston University, Boston, Mass.; Institute of Plastic Reconstructive and Aesthetic Surgery, University of Padova, Padova, Italy; and Harvard Medical School, Boston, Mass
| | - Khalil R Khouri
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Mass.; University of Michigan Medical School, Ann Arbor, Mich.; Gulliver Preparatory School, Pinecrest, Fla.; College of Engineering, Boston University, Boston, Mass.; Institute of Plastic Reconstructive and Aesthetic Surgery, University of Padova, Padova, Italy; and Harvard Medical School, Boston, Mass
| | - Luca Lancerotto
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Mass.; University of Michigan Medical School, Ann Arbor, Mich.; Gulliver Preparatory School, Pinecrest, Fla.; College of Engineering, Boston University, Boston, Mass.; Institute of Plastic Reconstructive and Aesthetic Surgery, University of Padova, Padova, Italy; and Harvard Medical School, Boston, Mass
| | - Dennis P Orgill
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Mass.; University of Michigan Medical School, Ann Arbor, Mich.; Gulliver Preparatory School, Pinecrest, Fla.; College of Engineering, Boston University, Boston, Mass.; Institute of Plastic Reconstructive and Aesthetic Surgery, University of Padova, Padova, Italy; and Harvard Medical School, Boston, Mass
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35
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Shakeel M, Raza S. Nonlinear Computational Model of Biological Cell Proliferation and Nutrient Delivery in a Bioreactor. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/am.2014.515222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Makhaniok A, Haranava Y, Goranov V, Panseri S, Semerikhina S, Russo A, Marcacci M, Dediu V. In silico prediction of the cell proliferation in porous scaffold using model of effective pore. Biosystems 2013; 114:227-37. [PMID: 24141144 DOI: 10.1016/j.biosystems.2013.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 08/01/2013] [Accepted: 10/03/2013] [Indexed: 10/26/2022]
Abstract
The mathematical prediction of cell proliferation in porous scaffold still remains a challenge. The analysis of existing models and experimental data confirms a need for a new solution, which takes into account cells" development on the scaffold pore walls as well as some additional parameters such as the pore size, cell density in cellular layers, the thickness of the growing cell layer and others. The simulations, presented below, are based on three main approaches. The first approach takes into account multilayer cell growth on the pore walls of the scaffold. The second approach is a simulation of cell proliferation in a discrete process as a continuous one. The third one is the representation of scaffold structure as a system of cylindrical channels. Oxygen (nutrient) mass transfer is realized inside these channels. The model, described below, proposes the new solution to time dependent description of cell proliferation in porous scaffold and optimized trophical conditions for tissue development.
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Affiliation(s)
- A Makhaniok
- BioDevice Systems, Praha 10, Vršovice, Bulharská 996/20, Czech Republic.
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37
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Microscale diffusion measurements and simulation of a scaffold with a permeable strut. Int J Mol Sci 2013; 14:20157-70. [PMID: 24152434 PMCID: PMC3821608 DOI: 10.3390/ijms141020157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/06/2013] [Accepted: 09/10/2013] [Indexed: 12/18/2022] Open
Abstract
Electrospun nanofibrous structures provide good performance to scaffolds in tissue engineering. We measured the local diffusion coefficients of 3-kDa FITC-dextran in line patterns of electrospun nanofibrous structures fabricated by the direct-write electrospinning (DWES) technique using the fluorescence recovery after photobleaching (FRAP) method. No significant differences were detected between DWES line patterns fabricated with polymer supplied at flow rates of 0.1 and 0.5 mL/h. The oxygen diffusion coefficients of samples were estimated to be ~92%–94% of the oxygen diffusion coefficient in water based on the measured diffusion coefficient of 3-kDa FITC-dextran. We also simulated cell growth and distribution within spatially patterned scaffolds with struts consisting of either oxygen-permeable or non-permeable material. The permeable strut scaffolds exhibited enhanced cell growth. Saturated depths at which cells could grow to confluence were 15% deeper for the permeable strut scaffolds than for the non-permeable strut scaffold.
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38
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Colom A, Galgoczy R, Almendros I, Xaubet A, Farré R, Alcaraz J. Oxygen diffusion and consumption in extracellular matrix gels: implications for designing three-dimensional cultures. J Biomed Mater Res A 2013; 102:2776-84. [PMID: 24027235 DOI: 10.1002/jbm.a.34946] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/26/2013] [Accepted: 09/06/2013] [Indexed: 11/10/2022]
Abstract
Three-dimensional (3D) cultures are increasingly used as tissue surrogates to study many physiopathological processes. However, to what extent current 3D culture protocols provide physiologic oxygen tension conditions remains ill defined. To address this limitation, oxygen tension was measured in a panel of acellular or cellularized extracellular matrix (ECM) gels with A549 cells, and analyzed in terms of oxygen diffusion and consumption. Gels included reconstituted basement membrane, fibrin and collagen. Oxygen diffusivity in acellular gels was up to 40% smaller than that of water, and the lower values were observed in the denser gels. In 3D cultures, physiologic oxygen tension was achieved after 2 days in dense (≥3 mg/mL) but not sparse gels, revealing that the latter gels are not suitable tissue surrogates in terms of oxygen distribution. In dense gels, we observed a dominant effect of ECM composition over density in oxygen consumption. All diffusion and consumption data were used in a simple model to estimate ranges for gel thickness, seeding density and time-window that may support physiologic oxygen tension. Thus, we identified critical variables for oxygen tension in ECM gels, and introduced a model to assess initial values of these variables, which may short-cut the optimization step of 3D culture studies.
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Affiliation(s)
- Adai Colom
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
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39
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Computational study of culture conditions and nutrient supply in a hollow membrane sheet bioreactor for large-scale bone tissue engineering. J Artif Organs 2013; 17:69-80. [DOI: 10.1007/s10047-013-0732-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 09/05/2013] [Indexed: 10/26/2022]
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40
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Abstract
Wound healing in the pediatric patient is of utmost clinical and social importance because hypertrophic scarring can have aesthetic and psychological sequelae, from early childhood to late adolescence. Wound healing is a well-orchestrated reparative response affecting the damaged tissue at the cellular, tissue, organ, and system scales. Although tremendous progress has been made toward understanding wound healing at the individual temporal and spatial scales, its effects across the scales remain severely understudied and poorly understood. Here, we discuss the critical need for systems-based computational modeling of wound healing across the scales, from short-term to long-term and from small to large. We illustrate the state of the art in systems modeling by means of three key signaling mechanisms: oxygen tension-regulating angiogenesis and revascularization; transforming growth factor-β (TGF-β) kinetics controlling collagen deposition; and mechanical stretch stimulating cellular mitosis and extracellular matrix (ECM) remodeling. The complex network of biochemical and biomechanical signaling mechanisms and the multiscale character of the healing process make systems modeling an integral tool in exploring personalized strategies for wound repair. A better mechanistic understanding of wound healing in the pediatric patient could open new avenues in treating children with skin disorders such as birth defects, skin cancer, wounds, and burn injuries.
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Affiliation(s)
| | - Ellen Kuhl
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305,Department of Bioengineering, Stanford University, Stanford, CA 94305
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41
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2-D coupled computational model of biological cell proliferation and nutrient delivery in a perfusion bioreactor. Math Biosci 2013; 242:86-94. [PMID: 23291465 DOI: 10.1016/j.mbs.2012.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 12/09/2012] [Accepted: 12/18/2012] [Indexed: 11/21/2022]
Abstract
Tissue engineering aims to regenerate, repair or replace organs or tissues which have become defective due to trauma, disease or age related degeneration. This engineering may take place within the patient's body or tissue can be regenerated in a bioreactor for later implantation into the patient. Regeneration of soft tissue is one of the most demanding applications of tissue engineering. Producing proper nutrient supply, uniform cell distribution and high cell density are the important challenges. Many experimental models exist for tissue growth in a bioreactor. It is important to put experiments into a theoretical framework. Mathematical modelling in terms of physical and biochemical mechanisms is the best tool to understand experimental results. In this work a mathematical model of convective and diffusive transport of nutrients and cell evolution in a perfusion bioreactor is developed. A cell-seeded porous scaffold is placed in a perfusion bioreactor and fluid delivers the nutrients to the cells for their growth. The model describes the key features of the tissue engineering processes which includes the interaction between the cell growth, variation of material permeability due to cell proliferation, flow of fluid through the material and delivery of nutrients to the cells. The fluid flow through the porous scaffold is modelled by Darcy's law, and the delivery of nutrients to the cells is modelled by the advection-diffusion equation. A non-linear reaction diffusion system is used to model the cell growth. The growth of cells is modelled by logistic growth. COMSOL (a commercial finite element solver) is used to numerically solve the model. The results show that the distribution of cells and total cell number in the scaffold does not depend on the initial cell density but depend on the material permeability.
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42
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Henderson TMA, Ladewig K, Haylock DN, McLean KM, O'Connor AJ. Cryogels for biomedical applications. J Mater Chem B 2013; 1:2682-2695. [DOI: 10.1039/c3tb20280a] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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43
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Kirsebom H, Elowsson L, Berillo D, Cozzi S, Inci I, Piskin E, Galaev IY, Mattiasson B. Enzyme-catalyzed crosslinking in a partly frozen state: a new way to produce supermacroporous protein structures. Macromol Biosci 2012; 13:67-76. [PMID: 23239633 DOI: 10.1002/mabi.201200343] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 10/26/2012] [Indexed: 02/02/2023]
Abstract
In this study a new way to produce supermacroporous protein structures was investigated. Enzyme-mediated crosslinking of gelatin or casein was performed in a partly frozen state, which yielded stable, protein-based cryogels. The reaction kinetics for the formation of cryogels were found to be fairly slow, most likely due to the low temperature (-12 °C) used or due to an increased viscosity owing to the cryo-concentration taking place. The produced cryogels were characterized with regards to their physical properties and in vitro degradation. Furthermore, cryogels produced from gelatin and casein were evaluated as potential scaffolds by fibroblast cultivation to confirm their in vitro biocompatibility. Gelatin- and casein-based scaffolds both supported cell proliferation and migration through the scaffold.
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Affiliation(s)
- Harald Kirsebom
- Department of Biotechnology, Lund University, P.O. Box 124, SE-22100, Lund, Sweden.
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44
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Bland E, Dréau D, Burg KJL. Overcoming hypoxia to improve tissue-engineering approaches to regenerative medicine. J Tissue Eng Regen Med 2012; 7:505-14. [PMID: 22761177 DOI: 10.1002/term.540] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 08/11/2011] [Accepted: 11/03/2011] [Indexed: 12/23/2022]
Abstract
The current clinical successes of tissue engineering are limited primarily to low-metabolism, acellular, pre-vascularized or thin tissues. Mass transport has been identified as the primary culprit, limiting the delivery of nutrients (such as oxygen and glucose) and removal of wastes, from tissues deep within a cellular scaffold. While strategies to develop sufficient vasculature to overcome hypoxia in vitro are promising, inconsistencies between the in vitro and the in vivo environments may still negate the effectiveness of large-volume tissue-engineered scaffolds. While a common theme in tissue engineering is to maximize oxygen supply, studies suggest that moderate oxygenation of cellular scaffolds during in vitro conditioning is preferable to high oxygen levels. Aiming for moderate oxygen values to prevent hypoxia while still promoting angiogenesis may be obtained by tailoring in vitro culture conditions to the oxygen environment the scaffold will experience upon implantation. This review discusses the causes and effects of tissue-engineering hypoxia and the optimization of oxygenation for the minimization of in vivo hypoxia.
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Affiliation(s)
- Erik Bland
- Department of Bioengineering, Clemson University, SC 29634, USA
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Yan X, Bergstrom DJ, Chen XB. Modeling of cell cultures in perfusion bioreactors. IEEE Trans Biomed Eng 2012; 59:2568-75. [PMID: 22772976 DOI: 10.1109/tbme.2012.2206077] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cultivating cells and tissues in bioreactors is a critical step in forming artificial tissues or organs prior to transplantation. Among various bioreactors, the perfusion bioreactor is known for its enhanced convection through the cell-scaffold constructs. Knowledge of mass transfer is essential for controlling the cell culture process; however, obtaining this information remains a challenging task. In this research, a novel mathematical model is developed to represent the nutrient transport and cell growth in a 3-D scaffold cultivated in a perfusion bioreactor. Numerical methods are employed to solve the equations involved, with a focus on identifying the effect of factors such as porosity, culturing time, and flow rate, which are controllable in the scaffold fabrication and culturing process, on cell cultures. To validate the new model, the results from the model simulations were compared to the experimental results extracted from the literature. With the validated model, further simulations were carried out to investigate the glucose and oxygen distribution and the cell growth within the cell-scaffold construct in a perfusion bioreactor, thus providing insight into the cell culture process.
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Affiliation(s)
- X Yan
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada.
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Unnikrishnan GU, Unnikrishnan VU, Reddy JN. Finite element model for nutrient distribution analysis of a hollow fiber membrane bioreactor. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2012; 28:229-238. [PMID: 25099327 DOI: 10.1002/cnm.1462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 06/15/2011] [Accepted: 06/16/2011] [Indexed: 06/03/2023]
Abstract
Hollow fiber membrane bioreactors (HFMB) are extensively used for the development of tissue substitutes for bones and cartilages. In an HFMB, the nutrient transport is dependent on the material properties of the porous scaffold and fiber membrane and also on the fluid flow through the hollow fiber. The difficulty in obtaining real-time data along with the presence of large number of variables in experimental studies have lead to increased application of computational models for the performance analysis of bioreactors. A major difficulty in the computational analysis of HFMB is the modeling of the interactions at the fluid and porous scaffold interfaces, which has often been neglected or incorporated using specific boundary conditions. In this study, a new FEM is developed to analyze the fluid flow in the fluid-porous region with the interface coupled directly into the FEM. Distribution of nutrients in the bioreactor is studied by coupling mass transport equations to the fluid-porous finite element framework. The new model is implemented to study the influence of permeability, cell density, and flow rate on the nutrient concentration distribution in the HFMB. The developed computational framework is an ideal tool to study fluid flow through porous-open channels and can also be used for the design of bioreactors for optimal tissue growth.
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Affiliation(s)
- G U Unnikrishnan
- Department of Mechanical Engineering, Boston University, Boston, MA 02215, USA
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Lambrechts D, Schrooten J, Van de Putte T, Van Oosterwyck H. Computational Modeling of Mass Transport and Its Relation to Cell Behavior in Tissue Engineering Constructs. COMPUTATIONAL MODELING IN TISSUE ENGINEERING 2012. [DOI: 10.1007/8415_2012_139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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HE JIANKANG, LI DICHEN, LIU YAXIONG, LI XIAO, XU SHANGLONG, LU BINGHENG. COMPUTATIONAL FLUID DYNAMICS FOR TISSUE ENGINEERING APPLICATIONS. J MECH MED BIOL 2011. [DOI: 10.1142/s0219519411004046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hydrodynamic cellular environment plays an important role in translating engineered tissue constructs into clinically useful grafts. However, the cellular fluid dynamic environment inside bioreactor systems is highly complex and it is normally impractical to experimentally characterize the local flow patterns at the cellular scale. Computational fluid dynamics (CFD) has been recognized as an invaluable and reliable alternative to investigate the complex relationship between hydrodynamic environments and the regeneration of engineered tissues at both the macroscopic and microscopic scales. This review describes the applications of CFD simulations to probe the hydrodynamic environment parameters (e.g., flow rate, shear stress, etc.) and the corresponding experimental validations. We highlight the use of CFD to optimize bioreactor design and scaffold architectures for improved ex-vivo hydrodynamic environments. It is envisioned that CFD could be used to customize specific hydrodynamic cellular environments to meet the unique requirements of different cell types in combination with advanced manufacturing techniques and finally facilitate the maturation of tissue-engineered constructs.
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Affiliation(s)
- JIANKANG HE
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - DICHEN LI
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - YAXIONG LIU
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - XIAO LI
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - SHANGLONG XU
- Department of Mechatronics Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - BINGHENG LU
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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Zhou H, Chen SB, Peng J, Wang CH. A study of effective diffusivity in porous scaffold by Brownian dynamics simulation. J Colloid Interface Sci 2010; 342:620-8. [DOI: 10.1016/j.jcis.2009.10.079] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 10/29/2009] [Accepted: 10/29/2009] [Indexed: 11/29/2022]
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Flegg JA, McElwain DLS, Byrne HM, Turner IW. A three species model to simulate application of Hyperbaric Oxygen Therapy to chronic wounds. PLoS Comput Biol 2009; 5:e1000451. [PMID: 19649306 PMCID: PMC2710516 DOI: 10.1371/journal.pcbi.1000451] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Accepted: 06/26/2009] [Indexed: 01/16/2023] Open
Abstract
Chronic wounds are a significant socioeconomic problem for governments worldwide. Approximately 15% of people who suffer from diabetes will experience a lower-limb ulcer at some stage of their lives, and 24% of these wounds will ultimately result in amputation of the lower limb. Hyperbaric Oxygen Therapy (HBOT) has been shown to aid the healing of chronic wounds; however, the causal reasons for the improved healing remain unclear and hence current HBOT protocols remain empirical. Here we develop a three-species mathematical model of wound healing that is used to simulate the application of hyperbaric oxygen therapy in the treatment of wounds. Based on our modelling, we predict that intermittent HBOT will assist chronic wound healing while normobaric oxygen is ineffective in treating such wounds. Furthermore, treatment should continue until healing is complete, and HBOT will not stimulate healing under all circumstances, leading us to conclude that finding the right protocol for an individual patient is crucial if HBOT is to be effective. We provide constraints that depend on the model parameters for the range of HBOT protocols that will stimulate healing. More specifically, we predict that patients with a poor arterial supply of oxygen, high consumption of oxygen by the wound tissue, chronically hypoxic wounds, and/or a dysfunctional endothelial cell response to oxygen are at risk of nonresponsiveness to HBOT. The work of this paper can, in some way, highlight which patients are most likely to respond well to HBOT (for example, those with a good arterial supply), and thus has the potential to assist in improving both the success rate and hence the cost-effectiveness of this therapy.
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Affiliation(s)
- Jennifer A. Flegg
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Donald L. S. McElwain
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Helen M. Byrne
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Ian W. Turner
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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