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Cao S, Bo R, Zhang Y. Polymeric Scaffolds for Regeneration of Central/Peripheral Nerves and Soft Connective Tissues. ADVANCED NANOBIOMED RESEARCH 2023. [DOI: 10.1002/anbr.202200147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Shunze Cao
- Applied Mechanics Laboratory Department of Engineering Mechanics Laboratory for Flexible Electronics Technology Tsinghua University Beijing 100084 China
| | - Renheng Bo
- Applied Mechanics Laboratory Department of Engineering Mechanics Laboratory for Flexible Electronics Technology Tsinghua University Beijing 100084 China
| | - Yihui Zhang
- Applied Mechanics Laboratory Department of Engineering Mechanics Laboratory for Flexible Electronics Technology Tsinghua University Beijing 100084 China
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Alginate as a Promising Biopolymer in Drug Delivery and Wound Healing: A Review of the State-of-the-Art. Int J Mol Sci 2022; 23:ijms23169035. [PMID: 36012297 PMCID: PMC9409034 DOI: 10.3390/ijms23169035] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 12/20/2022] Open
Abstract
Biopolymeric nanoparticulate systems hold favorable carrier properties for active delivery. The enhancement in the research interest in alginate formulations in biomedical and pharmaceutical research, owing to its biodegradable, biocompatible, and bioadhesive characteristics, reiterates its future use as an efficient drug delivery matrix. Alginates, obtained from natural sources, are the colloidal polysaccharide group, which are water-soluble, non-toxic, and non-irritant. These are linear copolymeric blocks of α-(1→4)-linked l-guluronic acid (G) and β-(1→4)-linked d-mannuronic acid (M) residues. Owing to the monosaccharide sequencing and the enzymatically governed reactions, alginates are well-known as an essential bio-polymer group for multifarious biomedical implementations. Additionally, alginate’s bio-adhesive property makes it significant in the pharmaceutical industry. Alginate has shown immense potential in wound healing and drug delivery applications to date because its gel-forming ability maintains the structural resemblance to the extracellular matrices in tissues and can be altered to perform numerous crucial functions. The initial section of this review will deliver a perception of the extraction source and alginate’s remarkable properties. Furthermore, we have aspired to discuss the current literature on alginate utilization as a biopolymeric carrier for drug delivery through numerous administration routes. Finally, the latest investigations on alginate composite utilization in wound healing are addressed.
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Syanda AM, Kringstad VI, Blackford SJI, Kjesbu JS, Ng SS, Ma L, Xiao F, Coron AE, Rokstad AMA, Modi S, Rashid ST, Strand BL. Sulfated Alginate Reduces Pericapsular Fibrotic Overgrowth on Encapsulated cGMP-Compliant hPSC-Hepatocytes in Mice. Front Bioeng Biotechnol 2022; 9:816542. [PMID: 35308825 PMCID: PMC8928731 DOI: 10.3389/fbioe.2021.816542] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/24/2021] [Indexed: 12/12/2022] Open
Abstract
Intra-peritoneal placement of alginate encapsulated human induced pluripotent stem cell-derived hepatocytes (hPSC-Heps) represents a potential new bridging therapy for acute liver failure. One of the rate-limiting steps that needs to be overcome to make such a procedure more efficacious and safer is to reduce the accumulation of fibrotic tissue around the encapsulated cells to allow the free passage of relevant molecules in and out for metabolism. Novel chemical compositions of alginate afford the possibility of achieving this aim. We accordingly used sulfated alginate and demonstrated that this material reduced fibrotic overgrowth whilst not impeding the process of encapsulation nor cell function. Cumulatively, this suggests sulfated alginate could be a more suitable material to encapsulate hPSC-hepatocyte prior to human use.
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Affiliation(s)
- Adam M. Syanda
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - Vera I. Kringstad
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Samuel J. I. Blackford
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - Joachim S. Kjesbu
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Soon Seng Ng
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - Liang Ma
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - Fang Xiao
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - Abba E. Coron
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Anne Mari A. Rokstad
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Sunil Modi
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - S. Tamir Rashid
- Department of Metabolism, Digestion and Reproduction, Imperial College London (ICL), London, United Kingdom
| | - Berit Løkensgard Strand
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- *Correspondence: Berit Løkensgard Strand,
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Li W, Lei X, Feng H, Li B, Kong J, Xing M. Layer-by-Layer Cell Encapsulation for Drug Delivery: The History, Technique Basis, and Applications. Pharmaceutics 2022; 14:pharmaceutics14020297. [PMID: 35214030 PMCID: PMC8874529 DOI: 10.3390/pharmaceutics14020297] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/28/2021] [Accepted: 01/24/2022] [Indexed: 12/17/2022] Open
Abstract
The encapsulation of cells with various polyelectrolytes through layer-by-layer (LbL) has become a popular strategy in cellular function engineering. The technique sprang up in 1990s and obtained tremendous advances in multi-functionalized encapsulation of cells in recent years. This review comprehensively summarized the basis and applications in drug delivery by means of LbL cell encapsulation. To begin with, the concept and brief history of LbL and LbL cell encapsulation were introduced. Next, diverse types of materials, including naturally extracted and chemically synthesized, were exhibited, followed by a complicated basis of LbL assembly, such as interactions within multilayers, charge distribution, and films morphology. Furthermore, the review focused on the protective effects against adverse factors, and bioactive payloads incorporation could be realized via LbL cell encapsulation. Additionally, the payload delivery from cell encapsulation system could be adjusted by environment, redox, biological processes, and functional linkers to release payloads in controlled manners. In short, drug delivery via LbL cell encapsulation, which takes advantage of both cell grafts and drug activities, will be of great importance in basic research of cell science and biotherapy for various diseases.
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Affiliation(s)
- Wenyan Li
- Department of Neurosurgery, First Affiliated Hospital, Army Medical University, 30 Gaotanyan Street, Chongqing 400038, China; (W.L.); (X.L.); (H.F.)
| | - Xuejiao Lei
- Department of Neurosurgery, First Affiliated Hospital, Army Medical University, 30 Gaotanyan Street, Chongqing 400038, China; (W.L.); (X.L.); (H.F.)
| | - Hua Feng
- Department of Neurosurgery, First Affiliated Hospital, Army Medical University, 30 Gaotanyan Street, Chongqing 400038, China; (W.L.); (X.L.); (H.F.)
| | - Bingyun Li
- Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506, USA;
| | - Jiming Kong
- Department of Human Anatomy and Cell Science, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, MB R3E 0J9, Canada
- Correspondence: (J.K.); (M.X.)
| | - Malcolm Xing
- Department of Mechanical Engineering, University of Manitoba, 75 Chancellors Circle, Winnipeg, MB R3T 5V6, Canada
- Correspondence: (J.K.); (M.X.)
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Ladeira B, Custodio C, Mano J. Core-Shell Microcapsules: Biofabrication and Potential Applications in Tissue Engineering and Regenerative Medicine. Biomater Sci 2022; 10:2122-2153. [DOI: 10.1039/d1bm01974k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The construction of biomaterial scaffolds that accurately recreate the architecture of living tissues in vitro is a major challenge in the field of tissue engineering and regenerative medicine. Core-shell microcapsules...
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Lopez-Mendez TB, Santos-Vizcaino E, Pedraz JL, Orive G, Hernandez RM. Cell microencapsulation technologies for sustained drug delivery: Latest advances in efficacy and biosafety. J Control Release 2021; 335:619-636. [PMID: 34116135 DOI: 10.1016/j.jconrel.2021.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 10/21/2022]
Abstract
The development of cell microencapsulation systems began several decades ago. However, today few systems have been tested in clinical trials. For this reason, in the last years, researchers have directed efforts towards trying to solve some of the key aspects that still limit efficacy and biosafety, the two major criteria that must be satisfied to reach the clinical practice. Regarding the efficacy, which is closely related to biocompatibility, substantial improvements have been made, such as the purification or chemical modification of the alginates that normally form the microspheres. Each of the components that make up the microcapsules has been carefully selected to avoid toxicities that can damage the encapsulated cells or generate an immune response leading to pericapsular fibrosis. As for the biosafety, researchers have developed biological circuits capable of actively responding to the needs of the patients to precisely and accurately release the demanded drug dose. Furthermore, the structure of the devices has been subject of study to adequately protect the encapsulated cells and prevent their spread in the body. The objective of this review is to describe the latest advances made by scientist to improve the efficacy and biosafety of cell microencapsulation systems for sustained drug delivery, also highlighting those points that still need to be optimized.
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Affiliation(s)
- Tania B Lopez-Mendez
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Edorta Santos-Vizcaino
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain
| | - Jose Luis Pedraz
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain
| | - Gorka Orive
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain; University Institute for Regenerative Medicine and Oral Implantology - UIRMI (UPV/EHU-Fundación Eduardo Anitua), BTI Biotechnology Institute, Vitoria-Gasteiz, Spain; Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Singapore.
| | - Rosa Maria Hernandez
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain.
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Hu S, Kuwabara R, Navarro Chica CE, Smink AM, Koster T, Medina JD, de Haan BJ, Beukema M, Lakey JRT, García AJ, de Vos P. Toll-like receptor 2-modulating pectin-polymers in alginate-based microcapsules attenuate immune responses and support islet-xenograft survival. Biomaterials 2020; 266:120460. [PMID: 33099059 DOI: 10.1016/j.biomaterials.2020.120460] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/03/2020] [Accepted: 10/18/2020] [Indexed: 12/14/2022]
Abstract
Encapsulation of pancreatic islets in alginate-microcapsules is used to reduce or avoid the application of life-long immunosuppression in preventing rejection. Long-term graft function, however, is limited due to varying degrees of host tissue responses against the capsules. Major graft-longevity limiting responses include inflammatory responses provoked by biomaterials and islet-derived danger-associated molecular patterns (DAMPs). This paper reports on a novel strategy for engineering alginate microcapsules presenting immunomodulatory polymer pectin with varying degrees of methyl-esterification (DM) to reduce these host tissue responses. DM18-pectin/alginate microcapsules show a significant decrease of DAMP-induced Toll-Like Receptor-2 mediated immune activation in vitro, and reduce peri-capsular fibrosis in vivo in mice compared to higher DM-pectin/alginate microcapsules and conventional alginate microcapsules. By testing efficacy of DM18-pectin/alginate microcapsules in vivo, we demonstrate that low-DM pectin support long-term survival of xenotransplanted rat islets in diabetic mice. This study provides a novel strategy to attenuate host responses by creating immunomodulatory capsule surfaces that attenuate activation of specific pro-inflammatory immune receptors locally at the transplantation site.
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Affiliation(s)
- Shuxian Hu
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands.
| | - Rei Kuwabara
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
| | - Carlos E Navarro Chica
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
| | - Alexandra M Smink
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
| | - Taco Koster
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
| | - Juan D Medina
- Coulter Department of Biomedical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA, 30332, USA
| | - Bart J de Haan
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
| | - Martin Beukema
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
| | - Jonathan R T Lakey
- Department of Surgery, University of California Irvine, 333 City Boulevard West Suite 1600, Orange, CA, 92868, USA; Department of Biomedical Engineering, University of California Irvine, 5200 Engineering Hall, Irvine, CA, 92697, USA
| | - Andrés J García
- Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA, 30332, USA
| | - Paul de Vos
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, EA 11, 9713 GZ, Groningen, the Netherlands
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Szabó L, Noverraz F, Gerber‐Lemaire S. Multicomponent Alginate‐Derived Hydrogel Microspheres Presenting Hybrid Ionic‐Covalent Network and Drug Eluting Properties. Helv Chim Acta 2020. [DOI: 10.1002/hlca.202000115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Luca Szabó
- Institute of Chemical Sciences and Engineering, Group for Functionalized Biomaterials Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC SCI-SB-SG Station 6 CH-1015 Lausanne Switzerland
| | - François Noverraz
- Institute of Chemical Sciences and Engineering, Group for Functionalized Biomaterials Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC SCI-SB-SG Station 6 CH-1015 Lausanne Switzerland
| | - Sandrine Gerber‐Lemaire
- Institute of Chemical Sciences and Engineering, Group for Functionalized Biomaterials Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC SCI-SB-SG Station 6 CH-1015 Lausanne Switzerland
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Hu S, de Vos P. Polymeric Approaches to Reduce Tissue Responses Against Devices Applied for Islet-Cell Encapsulation. Front Bioeng Biotechnol 2019; 7:134. [PMID: 31214587 PMCID: PMC6558039 DOI: 10.3389/fbioe.2019.00134] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/20/2019] [Indexed: 12/15/2022] Open
Abstract
Immunoisolation of pancreatic islets is a technology in which islets are encapsulated in semipermeable but immunoprotective polymeric membranes. The technology allows for successful transplantation of insulin-producing cells in the absence of immunosuppression. Different approaches of immunoisolation are currently under development. These approaches involve intravascular devices that are connected to the bloodstream and extravascular devices that can be distinguished in micro- and macrocapsules and are usually implanted in the peritoneal cavity or under the skin. The technology has been subject of intense fundamental research in the past decade. It has co-evolved with novel replenishable cell sources for cure of diseases such as Type 1 Diabetes Mellitus that need to be protected for the host immune system. Although the devices have shown significant success in animal models and even in human safety studies most technologies still suffer from undesired tissue responses in the host. Here we review the past and current approaches to modulate and reduce tissue responses against extravascular cell-containing micro- and macrocapsules with a focus on rational choices for polymer (combinations). Choices for polymers but also choices for crosslinking agents that induce more stable and biocompatible capsules are discussed. Combining beneficial properties of molecules in diblock polymers or application of these molecules or other anti-biofouling molecules have been reviewed. Emerging are also the principles of polymer brushes that prevent protein and cell-adhesion. Recently also immunomodulating biomaterials that bind to specific immune receptors have entered the field. Several natural and synthetic polymers and even combinations of these polymers have demonstrated significant improvement in outcomes of encapsulated grafts. Adequate polymeric surface properties have been shown to be essential but how the surface should be composed to avoid host responses remains to be identified. Current insight is that optimal biocompatible devices can be created which raises optimism that immunoisolating devices can be created that allows for long term survival of encapsulated replenishable insulin-producing cell sources for treatment of Type 1 Diabetes Mellitus.
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Affiliation(s)
- Shuixan Hu
- Division of Medical Biology, Department of Pathology and Medical Biology, Immunoendocrinology, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
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Gopi S, Amalraj A, Sukumaran NP, Haponiuk JT, Thomas S. Biopolymers and Their Composites for Drug Delivery: A Brief Review. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/masy.201800114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Sreeraj Gopi
- R&D Centre; Aurea Biolabs (P) Ltd, Kolenchery; Cochin 682311 Kerala India
- Chemical Faculty; Gdansk University of Technology; Gdańsk Poland
- International and Inter University Centre for Nanoscience and Nanotechnology; School of Chemical Sciences; Mahatma Gandhi University; Priyadarshini Hills P. O. Kottayam Kerala 686560 India
| | - Augustine Amalraj
- R&D Centre; Aurea Biolabs (P) Ltd, Kolenchery; Cochin 682311 Kerala India
| | | | | | - Sabu Thomas
- International and Inter University Centre for Nanoscience and Nanotechnology; School of Chemical Sciences; Mahatma Gandhi University; Priyadarshini Hills P. O. Kottayam Kerala 686560 India
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Gonzalez-Pujana A, Orive G, Pedraz JL, Santos-Vizcaino E, Hernandez RM. Alginate Microcapsules for Drug Delivery. SPRINGER SERIES IN BIOMATERIALS SCIENCE AND ENGINEERING 2018. [DOI: 10.1007/978-981-10-6910-9_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abstract
The principle of immunoisolation of cells is based on encapsulation of cells in immunoprotective but semipermeable membranes that protect cells from hazardous effects of the host immune system but allows ingress of nutrients and outgress of therapeutic molecules. The technology was introduced in 1933 but has only received its deserved attention for its therapeutic application for three decades now.In the past decade important advances have been made in creating capsules that provoke minimal or no inflammatory responses. There are however new emerging challenges. These challenges relate to optimal nutrition and oxygen supply as well as standardization and documentation of capsule properties.It is concluded that the proof of principle of applicability of encapsulated grafts for treatment of human disease has been demonstrated and merits optimism about its clinical potential. Further innovation requires a much more systematic approach in identifying crucial properties of capsules and cellular grafts to allow sound interpretations of the results.
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Affiliation(s)
- Paul de Vos
- Division of Immuno-Endocrinology, Departments of Pathology and Laboratory Medicine, University of Groningen, Groningen, Groningen, The Netherlands.
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Abstract
This chapter presents a description of standardized techniques used routinely in our laboratory to encapsulate different cell types using the alginate-PLL-alginate immunoisolation system. Given the importance of noninvasive tracking of encapsulated cell transplants, we present a detailed guidance to achieve maximum efficiency and functionality of the capsule preparations for optimal tracking posttransplantation. The provided protocols cover tracking of encapsulated cells using magnetic resonance (MR), X-ray, computed tomography (CT), and ultrasound (US) imaging. Practical suggestions to optimize each method with specific references to recommended suppliers are included.
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Gonzalez-Pujana A, Santos E, Orive G, Pedraz JL, Hernandez RM. Cell microencapsulation technology: Current vision of its therapeutic potential through the administration routes. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2017.03.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Vaithilingam V, Steinkjer B, Ryan L, Larsson R, Tuch BE, Oberholzer J, Rokstad AM. In Vitro and In Vivo Biocompatibility Evaluation of Polyallylamine and Macromolecular Heparin Conjugates Modified Alginate Microbeads. Sci Rep 2017; 7:11695. [PMID: 28916826 PMCID: PMC5600981 DOI: 10.1038/s41598-017-11989-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/29/2017] [Indexed: 11/09/2022] Open
Abstract
Host reactivity to biocompatible immunoisolation devices is a major challenge for cellular therapies, and a human screening model would be of great value. We designed new types of surface modified barium alginate microspheres, and evaluated their inflammatory properties using human whole blood, and the intraperitoneal response after three weeks in Wistar rats. Microspheres were modified using proprietary polyallylamine (PAV) and coupled with macromolecular heparin conjugates (Corline Heparin Conjugate, CHC). The PAV-CHC strategy resulted in uniform and stable coatings with increased anti-clot activity and low cytotoxicity. In human whole blood, PAV coating at high dose (100 µg/ml) induced elevated complement, leukocyte CD11b and inflammatory mediators, and in Wistar rats increased fibrotic overgrowth. Coating of high dose PAV with CHC significantly reduced these responses. Low dose PAV (10 µg/ml) ± CHC and unmodified alginate microbeads showed low responses. That the human whole blood inflammatory reactions paralleled the host response shows a link between inflammatory potential and initial fibrotic response. CHC possessed anti-inflammatory activity, but failed to improve overall biocompatibility. We conclude that the human whole blood assay is an efficient first-phase screening model for inflammation, and a guiding tool in development of new generation microspheres for cell encapsulation therapy.
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Affiliation(s)
- Vijayaganapathy Vaithilingam
- Materials Science and Engineering, Commonwealth Scientific and Industrial Research Organization (CSIRO), North Ryde, New South Wales, Australia
| | - Bjørg Steinkjer
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Liv Ryan
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Rolf Larsson
- Corline System AB, Uppsala, Sweden.,Department of Immunology, Genetics and Pathology, University of Uppsala, Uppsala, Sweden
| | - Bernard Edward Tuch
- Materials Science and Engineering, Commonwealth Scientific and Industrial Research Organization (CSIRO), North Ryde, New South Wales, Australia. .,School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia.
| | - Jose Oberholzer
- Department of Surgery, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Anne Mari Rokstad
- Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.,The Central Norway Regional Health Authority (RHA), Trondheim, Norway
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Vaithilingam V, Evans MDM, Lewy DM, Bean PA, Bal S, Tuch BE. Co-encapsulation and co-transplantation of mesenchymal stem cells reduces pericapsular fibrosis and improves encapsulated islet survival and function when allografted. Sci Rep 2017; 7:10059. [PMID: 28855611 PMCID: PMC5577272 DOI: 10.1038/s41598-017-10359-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 08/09/2017] [Indexed: 12/22/2022] Open
Abstract
Pericapsular fibrotic overgrowth (PFO) is associated with poor survival of encapsulated islets. A strategy to combat PFO is the use of mesenchymal stem cells (MSC). MSC have anti-inflammatory properties and their potential can be enhanced by stimulation with proinflammatory cytokines. This study investigated whether co-encapsulation or co-transplantation of MSC with encapsulated islets would reduce PFO and improve graft survival. Stimulating MSC with a cytokine cocktail of IFN-γ and TNF-α enhanced their immunosuppressive potential by increasing nitric oxide production and secreting higher levels of immunomodulatory cytokines. In vitro, co-encapsulation with MSC did not affect islet viability but significantly enhanced glucose-induced insulin secretion. In vivo, normoglycemia was achieved in 100% mice receiving islets co-encapsulated with stimulated MSC as opposed to 71.4% receiving unstimulated MSC and only 9.1% receiving encapsulated islets alone. Microcapsules retrieved from both unstimulated and stimulated MSC groups had significantly less PFO with improved islet viability and function compared to encapsulated islets alone. Levels of peritoneal immunomodulatory cytokines IL-4, IL-6, IL-10 and G-CSF were significantly higher in MSC co-encapsulated groups. Similar results were obtained when encapsulated islets and MSC were co-transplanted. In summary, co-encapsulation or co-transplantation of MSC with encapsulated islets reduced PFO and improved the functional outcome of allotransplants.
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Affiliation(s)
- Vijayaganapathy Vaithilingam
- Biomedical Manufacturing Research Program, Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing Flagship, North Ryde, New South Wales, Australia.
| | - Margaret D M Evans
- Biomedical Manufacturing Research Program, Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing Flagship, North Ryde, New South Wales, Australia
| | - Denise M Lewy
- Biomedical Manufacturing Research Program, Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing Flagship, North Ryde, New South Wales, Australia
| | - Penelope A Bean
- Biomedical Manufacturing Research Program, Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing Flagship, North Ryde, New South Wales, Australia
| | - Sumeet Bal
- Biomedical Manufacturing Research Program, Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing Flagship, North Ryde, New South Wales, Australia
| | - Bernard E Tuch
- Biomedical Manufacturing Research Program, Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing Flagship, North Ryde, New South Wales, Australia
- Australian Foundation for Diabetes Research, Sydney, New South Wales, Australia, previously at CSIRO Manufacturing Flagship, North Ryde, New South Wales, Australia
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17
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Agüero L, Zaldivar-Silva D, Peña L, Dias ML. Alginate microparticles as oral colon drug delivery device: A review. Carbohydr Polym 2017; 168:32-43. [DOI: 10.1016/j.carbpol.2017.03.033] [Citation(s) in RCA: 230] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/18/2017] [Accepted: 03/09/2017] [Indexed: 01/13/2023]
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Abstract
Transplantation of pancreatic islets encapsulated within immuno-protective microcapsules is a strategy that has the potential to overcome graft rejection without the need for toxic immunosuppressive medication. However, despite promising preclinical studies, clinical trials using encapsulated islets have lacked long-term efficacy, and although generally considered clinically safe, have not been encouraging overall. One of the major factors limiting the long-term function of encapsulated islets is the host's immunological reaction to the transplanted graft which is often manifested as pericapsular fibrotic overgrowth (PFO). PFO forms a barrier on the capsule surface that prevents the ingress of oxygen and nutrients leading to islet cell starvation, hypoxia and death. The mechanism of PFO formation is still not elucidated fully and studies using a pig model have tried to understand the host immune response to empty alginate microcapsules. In this review, the varied strategies to overcome or reduce PFO are discussed, including alginate purification, altering microcapsule geometry, modifying alginate chemical composition, co-encapsulation with immunomodulatory cells, administration of pharmacological agents, and alternative transplantation sites. Nanoencapsulation technologies, such as conformal and layer-by-layer coating technologies, as well as nanofiber, thin-film nanoporous devices, and silicone based NanoGland devices are also addressed. Finally, this review outlines recent progress in imaging technologies to track encapsulated cells, as well as promising perspectives concerning the production of insulin-producing cells from stem cells for encapsulation.
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Affiliation(s)
- Vijayaganapathy Vaithilingam
- Materials Science and Engineering, Commonwealth Scientific and Industrial Research Organization (CSIRO), North Ryde, New South Wales, Australia
| | - Sumeet Bal
- Materials Science and Engineering, Commonwealth Scientific and Industrial Research Organization (CSIRO), North Ryde, New South Wales, Australia
| | - Bernard E Tuch
- School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
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Yesilyurt V, Veiseh O, Doloff JC, Li J, Bose S, Xie X, Bader AR, Chen M, Webber MJ, Vegas AJ, Langer R, Anderson DG. A Facile and Versatile Method to Endow Biomaterial Devices with Zwitterionic Surface Coatings. Adv Healthc Mater 2017; 6:10.1002/adhm.201601091. [PMID: 27976536 PMCID: PMC5322155 DOI: 10.1002/adhm.201601091] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Indexed: 01/10/2023]
Abstract
The surface modification of implantable biomaterials with zwitterionic phosphorylcholine polymer is demonstrated through mussel-mimetic catecholamine polymer thin films. Using this method, the surfaces of alginate hydrogel microspheres and polystyrene microbeads, a model material known to produce robust foreign body responses and fibrosis, are successfully modified to reduce the tissue reaction by reducing the fibrosis in immunocompetent C57BL/6J mice.
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Affiliation(s)
- Volkan Yesilyurt
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Omid Veiseh
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Joshua C Doloff
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Jie Li
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Suman Bose
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Xi Xie
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Andrew R Bader
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Michael Chen
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Matthew J Webber
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Arturo J Vegas
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Robert Langer
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Daniel G Anderson
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Anesthesiology, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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Zhu H, Yu L, He Y, Lyu Y, Wang B. Microencapsulated Pig Islet Xenotransplantation as an Alternative Treatment of Diabetes. TISSUE ENGINEERING PART B-REVIEWS 2015; 21:474-89. [PMID: 26028249 DOI: 10.1089/ten.teb.2014.0499] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Haitao Zhu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
- Heart Center, Northwest Women's and Children's Hospital, Xi'an, China
| | - Liang Yu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
| | - Yayi He
- Department of Endocrinology, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
| | - Yi Lyu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
- Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Bo Wang
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, China
- Institute of Advanced Surgical Technology and Engineering, Xi'an Jiaotong University, Xi'an, China
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Paredes-Juarez GA, Sahasrabudhe NM, Tjoelker RS, de Haan BJ, Engelse MA, de Koning EJP, Faas MM, de Vos P. DAMP production by human islets under low oxygen and nutrients in the presence or absence of an immunoisolating-capsule and necrostatin-1. Sci Rep 2015; 5:14623. [PMID: 26419792 PMCID: PMC4588515 DOI: 10.1038/srep14623] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/24/2015] [Indexed: 12/18/2022] Open
Abstract
In between the period of transplantation and revascularization, pancreatic islets are exposed to low-oxygen and low-nutrient conditions. In the present study we mimicked those conditions in vitro to study the involvement of different cell death processes, release of danger-associated molecular patterns (DAMP), and associated in vitro immune activation. Under low-oxygen and low-nutrient conditions, apoptosis, autophagy and necroptosis occur in human islets. Necroptosis is responsible for DAMP-release such as dsDNA, uric acid, and HMGB1. The sensors of the innate immune system able to recognize these DAMPs are mainly TLR, NOD receptors, and C-type lectins. By using cell-lines with a non-functional adaptor molecule MyD88, we were able to show that the islet-derived DAMPs signal mainly via TLR. Immunoisolation in immunoprotective membranes reduced DAMP release and immune activation via retention of the relative large DAMPs in the capsules. Another effective strategy was suppressing necroptosis using the inhibitor nec-1. Although the effect on cell-survival was minor, nec-1 was able to reduce the release of HMGB1 and its associated immune activation. Our data demonstrate that in the immediate post-transplant period islets release DAMPs that in vitro enhance responses of innate immune cells. DAMP release can be reduced in vitro by immunoisolation or intervention with nec-1.
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Affiliation(s)
- Genaro A. Paredes-Juarez
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands
| | - Neha M. Sahasrabudhe
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands
| | - Reina S. Tjoelker
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands
| | - Bart J. de Haan
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands
| | - Marten A. Engelse
- Department of Nephrology, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands
| | - Eelco J. P. de Koning
- Department of Nephrology, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands
| | - Marijke M. Faas
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands
| | - Paul de Vos
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands
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22
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Spasojevic M, Paredes-Juarez GA, Vorenkamp J, de Haan BJ, Schouten AJ, de Vos P. Reduction of the inflammatory responses against alginate-poly-L-lysine microcapsules by anti-biofouling surfaces of PEG-b-PLL diblock copolymers. PLoS One 2014; 9:e109837. [PMID: 25347191 PMCID: PMC4209974 DOI: 10.1371/journal.pone.0109837] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 09/03/2014] [Indexed: 01/12/2023] Open
Abstract
Large-scale application of alginate-poly-L-lysine (alginate-PLL) capsules used for microencapsulation of living cells is hampered by varying degrees of success, caused by tissue responses against the capsules in the host. A major cause is proinflammatory PLL which is applied at the surface to provide semipermeable properties and immunoprotection. In this study, we investigated whether application of poly(ethylene glycol)-block-poly(L-lysine hydrochloride) diblock copolymers (PEG-b-PLL) can reduce the responses against PLL on alginate-matrices. The application of PEG-b-PLL was studied in two manners: (i) as a substitute for PLL or (ii) as an anti-biofouling layer on top of a proinflammatory, but immunoprotective, semipermeable alginate-PLL100 membrane. Transmission FTIR was applied to monitor the binding of PEG-b-PLL. When applied as a substitute for PLL, strong host responses in mice were observed. These responses were caused by insufficient binding of the PLL block of the diblock copolymers confirmed by FTIR. When PEG-b-PLL was applied as an anti-biofouling layer on top of PLL100 the responses in mice were severely reduced. Building an effective anti-biofouling layer required 50 hours as confirmed by FTIR, immunocytochemistry and XPS. Our study provides new insight in the binding requirements of polyamino acids necessary to provide an immunoprotective membrane. Furthermore, we present a relatively simple method to mask proinflammatory components on the surface of microcapsules to reduce host responses. Finally, but most importantly, our study illustrates the importance of combining physicochemical and biological methods to understand the complex interactions at the capsules' surface that determine the success or failure of microcapsules applicable for cell-encapsulation.
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Affiliation(s)
- Milica Spasojevic
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
- Departments of Pathology and Laboratory Medicine, section of Medical Biology, division of immunoendocrinology, University of Groningen, Groningen, The Netherlands
| | - Genaro A. Paredes-Juarez
- Departments of Pathology and Laboratory Medicine, section of Medical Biology, division of immunoendocrinology, University of Groningen, Groningen, The Netherlands
| | - Joop Vorenkamp
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Bart J. de Haan
- Departments of Pathology and Laboratory Medicine, section of Medical Biology, division of immunoendocrinology, University of Groningen, Groningen, The Netherlands
| | - Arend Jan Schouten
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Paul de Vos
- Departments of Pathology and Laboratory Medicine, section of Medical Biology, division of immunoendocrinology, University of Groningen, Groningen, The Netherlands
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23
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Paredes Juárez GA, Spasojevic M, Faas MM, de Vos P. Immunological and technical considerations in application of alginate-based microencapsulation systems. Front Bioeng Biotechnol 2014; 2:26. [PMID: 25147785 PMCID: PMC4123607 DOI: 10.3389/fbioe.2014.00026] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 07/17/2014] [Indexed: 01/31/2023] Open
Abstract
Islets encapsulated in immunoprotective microcapsules are being proposed as an alternative for insulin therapy for treatment of type 1 diabetes. Many materials for producing microcapsules have been proposed but only alginate does currently qualify as ready for clinical application. However, many different alginate-based capsule systems do exist. A pitfall in the field is that these systems are applied without a targeted strategy with varying degrees of success as a consequence. In the current review, the different properties of alginate-based systems are reviewed in view of future application in humans. The use of allogeneic and xenogeneic islet sources are discussed with acknowledging the different degrees of immune protection the encapsulation system should supply. Also issues such as oxygen supply and the role of danger associated molecular patterns (DAMPS) in immune activation are being reviewed. A common property of the encapsulation systems is that alginates for medical application should have an extreme high degree of purity and lack pathogen-associated molecular patterns (PAMPs) to avoid activation of the recipient’s immune system. Up to now, non-inflammatory alginates are only produced on a lab-scale and are not yet commercially available. This is a major pitfall on the route to human application. Also the lack of predictive pre-clinical models is a burden. The principle differences between relevant innate and adaptive immune responses in humans and other species are reviewed. Especially, the extreme differences between the immune system of non-human primates and humans are cumbersome as non-human primates may not be predictive of the immune responses in humans, as opposed to the popular belief of regulatory agencies. Current insight is that although the technology is versatile major research efforts are required for identifying the mechanical, immunological, and physico-chemical requirements that alginate-based capsules should meet for successful human application.
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Affiliation(s)
- Genaro Alberto Paredes Juárez
- Section of Immunoendocrinology, Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen , Groningen , Netherlands
| | - Milica Spasojevic
- Section of Immunoendocrinology, Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen , Groningen , Netherlands ; Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen , Groningen , Netherlands
| | - Marijke M Faas
- Section of Immunoendocrinology, Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen , Groningen , Netherlands
| | - Paul de Vos
- Section of Immunoendocrinology, Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen , Groningen , Netherlands
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de Vos P, Lazarjani HA, Poncelet D, Faas MM. Polymers in cell encapsulation from an enveloped cell perspective. Adv Drug Deliv Rev 2014; 67-68:15-34. [PMID: 24270009 DOI: 10.1016/j.addr.2013.11.005] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/26/2013] [Accepted: 11/13/2013] [Indexed: 02/07/2023]
Abstract
In the past two decades, many polymers have been proposed for producing immunoprotective capsules. Examples include the natural polymers alginate, agarose, chitosan, cellulose, collagen, and xanthan and synthetic polymers poly(ethylene glycol), polyvinyl alcohol, polyurethane, poly(ether-sulfone), polypropylene, sodium polystyrene sulfate, and polyacrylate poly(acrylonitrile-sodium methallylsulfonate). The biocompatibility of these polymers is discussed in terms of tissue responses in both the host and matrix to accommodate the functional survival of the cells. Cells should grow and function in the polymer network as adequately as in their natural environment. This is critical when therapeutic cells from scarce cadaveric donors are considered, such as pancreatic islets. Additionally, the cell mass in capsules is discussed from the perspective of emerging new insights into the release of so-called danger-associated molecular pattern molecules by clumps of necrotic therapeutic cells. We conclude that despite two decades of intensive research, drawing conclusions about which polymer is most adequate for clinical application is still difficult. This is because of the lack of documentation on critical information, such as the composition of the polymer, the presence or absence of confounding factors that induce immune responses, toxicity to enveloped cells, and the permeability of the polymer network. Only alginate has been studied extensively and currently qualifies for application. This review also discusses critical issues that are not directly related to polymers and are not discussed in the other reviews in this issue, such as the functional performance of encapsulated cells in vivo. Physiological endocrine responses may indeed not be expected because of the many barriers that the metabolites encounter when traveling from the blood stream to the enveloped cells and back to circulation. However, despite these diffusion barriers, many studies have shown optimal regulation, allowing us to conclude that encapsulated grafts do not always follow nature's course but are still a possible solution for many endocrine disorders for which the minute-to-minute regulation of metabolites is mandatory.
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Paredes-Juarez GA, de Haan BJ, Faas MM, de Vos P. A Technology Platform to Test the Efficacy of Purification of Alginate. MATERIALS (BASEL, SWITZERLAND) 2014; 7:2087-2103. [PMID: 28788557 PMCID: PMC5453257 DOI: 10.3390/ma7032087] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 02/12/2014] [Accepted: 03/05/2014] [Indexed: 01/08/2023]
Abstract
Alginates are widely used in tissue engineering technologies, e.g., in cell encapsulation, in drug delivery and various immobilization procedures. The success rates of these studies are highly variable due to different degrees of tissue response. A cause for this variation in success is, among other factors, its content of inflammatory components. There is an urgent need for a technology to test the inflammatory capacity of alginates. Recently, it has been shown that pathogen-associated molecular patterns (PAMPs) in alginate are potent immunostimulatories. In this article, we present the design and evaluation of a technology platform to assess (i) the immunostimulatory capacity of alginate or its contaminants, (ii) where in the purification process PAMPs are removed, and (iii) which Toll-like receptors (TLRs) and ligands are involved. A THP1 cell-line expressing pattern recognition receptors (PRRs) and the co-signaling molecules CD14 and MD2 was used to assess immune activation of alginates during the different steps of purification of alginate. To determine if this activation was mediated by TLRs, a THP1-defMyD88 cell-line was applied. This cell-line possesses a non-functional MyD88 coupling protein, necessary for activating NF-κB via TLRs. To identify the specific TLRs being activated by the PAMPs, we use different human embryonic kidney (HEK) cell-line that expresses only one specific TLR. Finally, specific enzyme-linked immunosorbent assays (ELISAs) were applied to identify the specific PAMP. By applying this three-step procedure, we can screen alginate in a manner, which is both labor and cost efficient. The efficacy of the platform was evaluated with an alginate that did not pass our quality control. We demonstrate that this alginate was immunostimulatory, even after purification due to reintroduction of the TLR5 activating flagellin. In addition, we tested two commercially available purified alginates. Our experiments show that these commercial alginates contained peptidoglycan, lipoteichoic acid, flagellin, and even lipopolysaccharides (LPS). The platform presented here can be used to evaluate the efficacy of purification procedures in removing PAMPs from alginates in a cost-efficient manner.
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Affiliation(s)
- Genaro A Paredes-Juarez
- Department of Pathology and Medical Biology, Section of Immunoendocrinology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, EA11, 9700 RB Groningen, The Netherlands.
| | - Bart J de Haan
- Department of Pathology and Medical Biology, Section of Immunoendocrinology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, EA11, 9700 RB Groningen, The Netherlands.
| | - Marijke M Faas
- Department of Pathology and Medical Biology, Section of Immunoendocrinology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, EA11, 9700 RB Groningen, The Netherlands.
| | - Paul de Vos
- Department of Pathology and Medical Biology, Section of Immunoendocrinology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, EA11, 9700 RB Groningen, The Netherlands.
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