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Dorchei F, Heydari A, Kroneková Z, Kronek J, Pelach M, Cseriová Z, Chorvát D, Zúñiga-Navarrete F, Rios PD, McGarrigle J, Ghani S, Isa D, Joshi I, Vasuthas K, Rokstad AMA, Oberholzer J, Raus V, Lacík I. Postmodification with Polycations Enhances Key Properties of Alginate-Based Multicomponent Microcapsules. Biomacromolecules 2024; 25:4118-4138. [PMID: 38857534 DOI: 10.1021/acs.biomac.4c00222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Postmodification of alginate-based microspheres with polyelectrolytes (PEs) is commonly used in the cell encapsulation field to control microsphere stability and permeability. However, little is known about how different applied PEs shape the microsphere morphology and properties, particularly in vivo. Here, we addressed this question using model multicomponent alginate-based microcapsules postmodified with PEs of different charge and structure. We found that the postmodification can enhance or impair the mechanical resistance and biocompatibility of microcapsules implanted into a mouse model, with polycations surprisingly providing the best results. Confocal Raman microscopy and confocal laser scanning microscopy (CLSM) analyses revealed stable interpolyelectrolyte complex layers within the parent microcapsule, hindering the access of higher molar weight PEs into the microcapsule core. All microcapsules showed negative surface zeta potential, indicating that the postmodification PEs get hidden within the microcapsule membrane, which agrees with CLSM data. Human whole blood assay revealed complex behavior of microcapsules regarding their inflammatory and coagulation potential. Importantly, most of the postmodification PEs, including polycations, were found to be benign toward the encapsulated model cells.
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Affiliation(s)
- Faeze Dorchei
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
| | - Abolfazl Heydari
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
- National Institute of Rheumatic Diseases, Nábrežie I. Krasku 4, 921 12 Piešt'any, Slovakia
| | - Zuzana Kroneková
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
- National Institute of Rheumatic Diseases, Nábrežie I. Krasku 4, 921 12 Piešt'any, Slovakia
| | - Juraj Kronek
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
- National Institute of Rheumatic Diseases, Nábrežie I. Krasku 4, 921 12 Piešt'any, Slovakia
| | - Michal Pelach
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
| | - Zuzana Cseriová
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
| | - Dušan Chorvát
- Department of Biophotonics, International Laser Centre, Slovak Centre of Scientific and Technical Information, Ilkovičova 3, 841 04 Bratislava, Slovakia
| | - Fernando Zúñiga-Navarrete
- Department of Proteomics, Institute of Virology, Biomedical Research Center of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 05 Bratislava, Slovakia
| | - Peter D Rios
- CellTrans, Inc., 2201 W. Campbell Park Dr., Chicago, Illinois 60612, United States
| | - James McGarrigle
- CellTrans, Inc., 2201 W. Campbell Park Dr., Chicago, Illinois 60612, United States
| | - Sofia Ghani
- CellTrans, Inc., 2201 W. Campbell Park Dr., Chicago, Illinois 60612, United States
| | - Douglas Isa
- CellTrans, Inc., 2201 W. Campbell Park Dr., Chicago, Illinois 60612, United States
| | - Ira Joshi
- CellTrans, Inc., 2201 W. Campbell Park Dr., Chicago, Illinois 60612, United States
| | - Kalaiyarasi Vasuthas
- Centre of Molecular Inflammation Research (CEMIR), Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Prinsesse Kristinas gt.1, NO-7491 Trondheim, Norway
| | - Anne Mari A Rokstad
- Centre of Molecular Inflammation Research (CEMIR), Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Prinsesse Kristinas gt.1, NO-7491 Trondheim, Norway
| | - José Oberholzer
- CellTrans, Inc., 2201 W. Campbell Park Dr., Chicago, Illinois 60612, United States
- Department of Visceral Surgery and Transplantation, University Hospital Zurich, Raemistrasse 100, 8091 Zurich, Switzerland
| | - Vladimír Raus
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Igor Lacík
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia
- National Institute of Rheumatic Diseases, Nábrežie I. Krasku 4, 921 12 Piešt'any, Slovakia
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Belkova M, Janegova T, Hrabarova E, Nahalka J. Physiologically Aggregated LacZ Applied in Trehalose Galactosylation in a Recycled Batch Mode. Life (Basel) 2023; 13:1619. [PMID: 37629477 PMCID: PMC10455999 DOI: 10.3390/life13081619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/17/2023] [Accepted: 07/22/2023] [Indexed: 08/27/2023] Open
Abstract
Galactooligosaccharides obtained via β-galactosidase transgalactosylation have health-promoting properties and are widely recognized as effective prebiotics. Trehalose-based galactooligosaccharides could be introduced into food and pharmaceutical industries similarly to trehalose. In light of this, new technological approaches are needed. Recently, in vivo enzyme immobilizations for recombinant proteins have been introduced, and physiological aggregation into active inclusion bodies (aIBs) has emerged as one such method of in vivo immobilization. To prepare LacZ β-galactosidase in the form of aIBs, we used a short 10 amino acid aggregation-prone tag. These native protein particles were simply washed from the cell lysate and applied in trehalose galactosylation in a recycled batch mode. In this study, aIBs entrapped in alginate beads, encapsulated in alginate/cellulose sulfate/poly(methylene-co-guanidine) capsules and magnetized were compared with free aIBs. Alginate/cellulose sulfate/PMCG capsules showed more suitable properties and applicability for biotransformation of trehalose at its high concentration (25%, w/v) and elevated temperature (50 °C).
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Affiliation(s)
- Martina Belkova
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
| | - Tatiana Janegova
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
| | - Eva Hrabarova
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
| | - Jozef Nahalka
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dubravska Cesta 9, SK-84538 Bratislava, Slovakia; (M.B.)
- Institute of Chemistry, Centre of Excellence for White-Green Biotechnology, Slovak Academy of Sciences, Trieda Andreja Hlinku 2, SK-94976 Nitra, Slovakia
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3
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Wang YL, Hu JJ. Sub-100-micron calcium-alginate microspheres: Preparation by nitrogen flow focusing, dependence of spherical shape on gas streams and a drug carrier using acetaminophen as a model drug. Carbohydr Polym 2021; 269:118262. [PMID: 34294295 DOI: 10.1016/j.carbpol.2021.118262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 12/28/2022]
Abstract
We developed a miniature gas-liquid coaxial flow device using glass capillaries, aiming to produce sub-100-μm Ca-alginate microspheres. Depending on collecting distance and the flow rates of nitrogen gas and alginate solution, however, Ca-alginate microparticles of different shapes were obtained. Spherical, monodisperse microparticles (microspheres) could only be obtained at certain gas flow rates and within a corresponding range of collecting distance. The result suggests that, for particles of this size, the gas flow rate and collecting distance are crucial for the formation of the spherical shape. We evaluated, as an example of its applications, the microsphere as a drug carrier using acetaminophen as a model drug. Large (~150 μm) and small (~70 μm) drug-loaded microspheres were prepared using two respective devices. Specifically, the drug-loaded microspheres were complexed with chitosan of different molecular weights. The dependence of in vitro drug release on the microsphere size and the chitosan molecular weight was examined. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Alginic acid sodium salt (PubChem CID: 5102882); Chitosan (PubChem CID: 71853); Calcium chloride (PubChem CID: 5284359); Sodium chloride (PubChem CID: 5234); Acetaminophen (PubChem CID: 1983); Polydimethylsiloxane (PubChem CID: 24771); n-Octadecyltrimethoxysilane (PubChem CID: 76486).
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Affiliation(s)
- Ying-Lin Wang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Jin-Jia Hu
- Department of Mechanical Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan; Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan.
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Truong V, Nguyen PT, Truong VT. The prediction model of nozzle height in liquid jet‐drop method to produce Ca‐alginate beads under microencapsulation process. J FOOD PROCESS ENG 2021. [DOI: 10.1111/jfpe.13663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vinh Truong
- Department of Chemical Engineering Nong Lam University Ho Chi Minh City Vietnam
| | - Phuong T. Nguyen
- Department of Chemical Engineering Nong Lam University Ho Chi Minh City Vietnam
| | - Vy T. Truong
- Department of Chemical Engineering Nong Lam University Ho Chi Minh City Vietnam
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Calabrese V, Califano D, da Silva MA, Schmitt J, Bryant SJ, Hossain KMZ, Percebom AM, Pérez Gramatges A, Scott JL, Edler KJ. Core-Shell Spheroidal Hydrogels Produced via Charge-Driven Interfacial Complexation. ACS APPLIED POLYMER MATERIALS 2020; 2:1213-1221. [PMID: 32296779 PMCID: PMC7147256 DOI: 10.1021/acsapm.9b01086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 02/12/2020] [Indexed: 06/11/2023]
Abstract
Through charge-driven interfacial complexation, we produced millimeter-sized spheroidal hydrogels (SH) with a core-shell structure allowing long-term stability in aqueous media. The SH were fabricated by extruding, dropwise, a cationic cellulose nanofibril (CCNF) dispersion into an oppositely charged poly(acrylic acid) (PAA) bath. The SH have a solid-like CCNF-PAA shell, acting as a semipermeable membrane, and a liquid-like CCNF suspension in the core. Swelling behavior of the SH was dependent on the osmotic pressure of the aging media. Swelling could be suppressed by increasing the ionic strength of the media as this enhanced interfibrillar interactions and thus strengthened the outer gel membrane. We further validated a potential application of SH as reusable matrixes for glucose oxidase (GOx) entrapment, where the SH work as microreactors from which substrate and product are freely able to migrate through the SH shell while avoiding enzyme leakage.
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Affiliation(s)
- Vincenzo Calabrese
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Davide Califano
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
- Centre for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Marcelo A da Silva
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Julien Schmitt
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Saffron J Bryant
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Kazi M Zakir Hossain
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Ana M Percebom
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), 22451-900 Rio de Janeiro, RJ, Brazil
| | - Aurora Pérez Gramatges
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), 22451-900 Rio de Janeiro, RJ, Brazil
| | - Janet L Scott
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
- Centre for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Karen J Edler
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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Wang T. Successful diabetes management without immunosuppressivedrugs in NHP model has been demonstrated. Encapsulation system with taperednanopore conduits achieved normal glycaemia with regulated insulin release. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 46:S1162-S1168. [DOI: 10.1080/21691401.2018.1533847] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Taylor Wang
- Department of Mechanical Engineering, School of Engineering, Vanderbilt University, Nashville, TN, USA
- Applied Physics Program, Vanderbilt University, Nashville, TN, USA
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7
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Orive G, Santos-Vizcaino E, Pedraz JL, Hernandez RM, Vela Ramirez JE, Dolatshahi-Pirouz A, Khademhosseini A, Peppas NA, Emerich DF. 3D cell-laden polymers to release bioactive products in the eye. Prog Retin Eye Res 2019; 68:67-82. [DOI: 10.1016/j.preteyeres.2018.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 10/02/2018] [Accepted: 10/09/2018] [Indexed: 12/16/2022]
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8
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Kroneková Z, Pelach M, Mazancová P, Uhelská L, Treľová D, Rázga F, Némethová V, Szalai S, Chorvát D, McGarrigle JJ, Omami M, Isa D, Ghani S, Majková E, Oberholzer J, Raus V, Šiffalovič P, Lacík I. Structural changes in alginate-based microspheres exposed to in vivo environment as revealed by confocal Raman microscopy. Sci Rep 2018; 8:1637. [PMID: 29374272 PMCID: PMC5785987 DOI: 10.1038/s41598-018-20022-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/11/2018] [Indexed: 12/20/2022] Open
Abstract
A next-generation cure for type 1 diabetes relies on immunoprotection of insulin-producing cells, which can be achieved by their encapsulation in microspheres made of non-covalently crosslinked hydrogels. Treatment success is directly related to the microsphere structure that is characterized by the localization of the polymers constituting the hydrogel material. However, due to the lack of a suitable analytical method, it is presently unknown how the microsphere structure changes in vivo, which complicates evaluation of different encapsulation approaches. Here, confocal Raman microscopy (CRM) imaging was tailored to serve as a powerful new tool for tracking structural changes in two major encapsulation designs, alginate-based microbeads and multi-component microcapsules. CRM analyses before implantation and after explantation from a mouse model revealed complete loss of the original heterogeneous structure in the alginate microbeads, making the intentionally high initial heterogeneity a questionable design choice. On the other hand, the structural heterogeneity was conserved in the microcapsules, which indicates that this design will better retain its immunoprotective properties in vivo. In another application, CRM was used for quantitative mapping of the alginate concentration throughout the microbead volume. Such data provide invaluable information about the microenvironment cells would encounter upon their encapsulation in alginate microbeads.
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Affiliation(s)
- Zuzana Kroneková
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Michal Pelach
- Department of Multilayers and Nanostructures, Institute of Physics of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 11, Bratislava, Slovakia
| | - Petra Mazancová
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Lucia Uhelská
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Dušana Treľová
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Filip Rázga
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Veronika Némethová
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Szabolcs Szalai
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia
| | - Dušan Chorvát
- Department of Biophotonics, International Laser Center, Ilkovicova 3, 841 04, Bratislava, Slovakia
| | - James J McGarrigle
- Division of Transplantation, Department of Surgery, University of Illinois at Chicago, 840 South Wood Street, Chicago, Illinois, 60612, USA
| | - Mustafa Omami
- Division of Transplantation, Department of Surgery, University of Illinois at Chicago, 840 South Wood Street, Chicago, Illinois, 60612, USA
| | - Douglas Isa
- Division of Transplantation, Department of Surgery, University of Illinois at Chicago, 840 South Wood Street, Chicago, Illinois, 60612, USA
| | - Sofia Ghani
- Division of Transplantation, Department of Surgery, University of Illinois at Chicago, 840 South Wood Street, Chicago, Illinois, 60612, USA
| | - Eva Majková
- Department of Multilayers and Nanostructures, Institute of Physics of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 11, Bratislava, Slovakia
| | - José Oberholzer
- Division of Transplantation, Department of Surgery, University of Illinois at Chicago, 840 South Wood Street, Chicago, Illinois, 60612, USA
| | - Vladimír Raus
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia.,Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06, Prague 6, Czech Republic
| | - Peter Šiffalovič
- Department of Multilayers and Nanostructures, Institute of Physics of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 11, Bratislava, Slovakia
| | - Igor Lacík
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41, Bratislava, Slovakia.
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Polyelectrolyte Complex Beads by Novel Two-Step Process for Improved Performance of Viable Whole-Cell Baeyer-Villiger Monoxygenase by Immobilization. Catalysts 2017. [DOI: 10.3390/catal7110353] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Gravastrand C, Hamad S, Fure H, Steinkjer B, Ryan L, Oberholzer J, Lambris JD, Lacík I, Mollnes TE, Espevik T, Brekke OL, Rokstad AM. Alginate microbeads are coagulation compatible, while alginate microcapsules activate coagulation secondary to complement or directly through FXII. Acta Biomater 2017; 58:158-167. [PMID: 28576714 DOI: 10.1016/j.actbio.2017.05.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/05/2017] [Accepted: 05/30/2017] [Indexed: 12/11/2022]
Abstract
Alginate microspheres are presently under evaluation for future cell-based therapy. Their ability to induce harmful host reactions needs to be identified for developing the most suitable devices and efficient prevention strategies. We used a lepirudin based human whole blood model to investigate the coagulation potentials of alginate-based microspheres: alginate microbeads (Ca/Ba Beads), alginate poly-l-lysine microcapsules (APA and AP microcapsules) and sodium alginate-sodium cellulose sulfate-poly(methylene-co-cyanoguanidine) microcapsules (PMCG microcapsules). Coagulation activation measured by prothrombin fragments 1+2 (PTF1.2) was rapidly and markedly induced by the PMCG microcapsules, delayed and lower induced by the APA and AP microcapsules, and not induced by the Ca/Ba Beads. Monocytes tissue factor (TF) expression was similarly activated by the microcapsules, whereas not by the Ca/Ba Beads. PMCG microcapsules-induced PTF1.2 was abolished by FXII inhibition (corn trypsin inhibitor), thus pointing to activation through the contact pathway. PTF1.2 induced by the AP and APA microcapsules was inhibited by anti-TF antibody, pointing to a TF driven coagulation. The TF induced coagulation was inhibited by the complement inhibitors compstatin (C3 inhibition) and eculizumab (C5 inhibition), revealing a complement-coagulation cross-talk. This is the first study on the coagulation potentials of alginate microspheres, and identifies differences in activation potential, pathways and possible intervention points. STATEMENT OF SIGNIFICANCE Alginate microcapsules are prospective candidate materials for cell encapsulation therapy. The material surface must be free of host cell adhesion to ensure free diffusion of nutrition and oxygen to the encapsulated cells. Coagulation activation is one gateway to cellular overgrowth through deposition of fibrin. Herein we used a physiologically relevant whole blood model to investigate the coagulation potential of alginate microcapsules and microbeads. The coagulation potentials and the pathways of activation were depending on the surface properties of the materials. Activation of the complement system could also be involved, thus emphasizing a complement-coagulation cross-talk. Our findings points to complement and coagulation inhibition as intervention point for preventing host reactions, and enhance functional cell-encapsulation devices.
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Affiliation(s)
- Caroline Gravastrand
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Shamal Hamad
- Research Laboratory, Nordland Hospital, 8092 Bodø, Norway
| | - Hilde Fure
- Research Laboratory, Nordland Hospital, 8092 Bodø, Norway
| | - Bjørg Steinkjer
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Liv Ryan
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Josè Oberholzer
- Department of Surgery/Division of Transplantation, University of Illinois at Chicago, IL, USA
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Igor Lacík
- Department for Biomaterials Research, Polymer Institute of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Tom Eirik Mollnes
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Research Laboratory, Nordland Hospital, 8092 Bodø, Norway; Faculty of Health Sciences, K.G. Jebsen Thrombosis Research and Expertise Center, The Arctic University of Norway, Tromsø, 9037 Tromsø, Norway; Department of Immunology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway; K.G. Jebsen Inflammatory Research Center, University of Oslo, 0424 Oslo, Norway
| | - Terje Espevik
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ole-Lars Brekke
- Research Laboratory, Nordland Hospital, 8092 Bodø, Norway; Faculty of Health Sciences, K.G. Jebsen Thrombosis Research and Expertise Center, The Arctic University of Norway, Tromsø, 9037 Tromsø, Norway
| | - Anne Mari Rokstad
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Clinic of Surgery, Centre for Obesity, St. Olavs University Hospital, Trondheim, Norway; Central Norway Regional Health Authority, Norway.
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11
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Takacova M, Hlouskova G, Zatovicova M, Benej M, Sedlakova O, Kopacek J, Pastorek J, Lacik I, Pastorekova S. Encapsulation of anti-carbonic anhydrase IX antibody in hydrogel microspheres for tumor targeting. J Enzyme Inhib Med Chem 2016; 31:110-118. [PMID: 27140748 DOI: 10.1080/14756366.2016.1177523] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Encapsulation is a well-established method of biomaterial protection, controlled release, and efficient delivery. Here we evaluated encapsulation of monoclonal antibody M75 directed to tumor biomarker carbonic anhydrase IX (CA IX) into alginate microbeads (SA-beads) or microcapsules made of sodium alginate, cellulose sulfate, and poly(methylene-co-guanidine) (PMCG). M75 antibody release was quantified using ELISA and its binding properties were assessed by immunodetection methods. SA-beads showed rapid M75 antibody release in the first hour, followed by steady release during the whole experiment of 7 days. In contrast, the M75 release from PMCG capsules was gradual, reaching the maximum concentration on the 7th day. The release was more efficient at pH 6.8 compared to pH 7.4. The released antibody could recognize CA IX, and target the CA IX-positive cells in 3D spheroids. In conclusion, SA-beads and PMCG microcapsules can be considered as promising antibody reservoirs for targeting of cancer cells.
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Affiliation(s)
- Martina Takacova
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia.,b Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute , Brno , Czech Republic , and
| | - Gabriela Hlouskova
- c Department for Biomaterials Research , Polymer Institute, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Miriam Zatovicova
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Martin Benej
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Olga Sedlakova
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Juraj Kopacek
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Jaromir Pastorek
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Igor Lacik
- c Department for Biomaterials Research , Polymer Institute, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Silvia Pastorekova
- a Department of Molecular Medicine , Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences , Bratislava , Slovakia.,b Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute , Brno , Czech Republic , and
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12
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Zhang Q, Lin D, Yao S. Review on biomedical and bioengineering applications of cellulose sulfate. Carbohydr Polym 2015; 132:311-22. [DOI: 10.1016/j.carbpol.2015.06.041] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 02/06/2023]
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Abstract
INTRODUCTION Islet transplantation can treat the most severe cases of type 1 diabetes but it currently requires deceased donor pancreata as an islet source and chronic immunosuppression to prevent rejection and recurrence of autoimmunity. Stem cell-derived insulin-producing cells may address the shortage of organ donors, whereas cell encapsulation may reduce or eliminate the requirement for immunosuppression, minimizing the risks associated with the islet transplantation procedure, and potentially prolonging graft survival. AREAS COVERED This review focuses on the design principles for immunoisolation devices and on stem cell differentiation into insulin-producing cell products. The reader will gain understanding of the different types of immunoisolation devices and the key parameters that affect the outcome of the encapsulated graft. Progresses in stem cell differentiation towards mature endocrine islet cells, including the most recent clinical trials and the challenges associated with the application of immunoisolation devices designed for primary islets to stem-cell products, are also discussed. EXPERT OPINION Recent advancements in the field of stem cell-derived islet cell products and immunoisolation strategies hold great promise for type 1 diabetes. However, a combination product including both cells and an immunoisolation strategy still needs to be optimized and tested for safety and efficacy.
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Affiliation(s)
- Alice Anna Tomei
- University of Miami Miller School of Medicine, Diabetes Research Institute , 1450 NW 10th Avenue, Miami, FL 33136 , USA +1 305 243 3469 ;
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Physical and Bioengineering Properties of Polyvinyl Alcohol Lens-Shaped Particles Versus Spherical Polyelectrolyte Complex Microcapsules as Immobilisation Matrices for a Whole-Cell Baeyer–Villiger Monooxygenase. Appl Biochem Biotechnol 2014; 174:1834-49. [DOI: 10.1007/s12010-014-1174-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/15/2014] [Indexed: 12/30/2022]
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Scharp DW, Marchetti P. Encapsulated islets for diabetes therapy: history, current progress, and critical issues requiring solution. Adv Drug Deliv Rev 2014; 67-68:35-73. [PMID: 23916992 DOI: 10.1016/j.addr.2013.07.018] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/10/2013] [Accepted: 07/22/2013] [Indexed: 02/07/2023]
Abstract
Insulin therapy became a reality in 1921 dramatically saving lives of people with diabetes, but not protecting them from long-term complications. Clinically successful free islet implants began in 1989 but require life long immunosuppression. Several encapsulated islet approaches have been ongoing for over 30 years without defining a clinically relevant product. Macro-devices encapsulating islet mass in a single device have shown long-term success in large animals but human trials have been limited by critical challenges. Micro-capsules using alginate or similar hydrogels encapsulate individual islets with many hundreds of promising rodent results published, but a low incidence of successful translation to large animal and human results. Reduction of encapsulated islet mass for clinical transplantation is in progress. This review covers the status of both early and current studies including the presentation of corporate efforts involved. It concludes by defining the critical items requiring solution to enable a successful clinical diabetes therapy.
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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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The induction of cytokines by polycation containing microspheres by a complement dependent mechanism. Biomaterials 2013; 34:621-30. [DOI: 10.1016/j.biomaterials.2012.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/04/2012] [Indexed: 12/28/2022]
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Controlled release of Pantoea agglomerans E325 for biocontrol of fire blight disease of apple. J Control Release 2012; 161:109-15. [PMID: 22516094 DOI: 10.1016/j.jconrel.2012.03.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 03/19/2012] [Accepted: 03/31/2012] [Indexed: 11/24/2022]
Abstract
Microencapsulation and controlled release of the biocontrol agent Pantoea agglomerans strain E325 (E325), an antagonist to the bacterial plant pathogen Erwinia amylovora that causes fire blight, a devastating disease of apple and pear, have been investigated. Uniform core-shell alginate microcapsules (AMCs), 60-300 μm in diameter, were fabricated to encapsulate E325 within the core, along with nutrients, to preserve viability and promote proliferation. Controlled release of E325 was achieved by separately adjusting alginate concentrations in the shell and core solutions, and by modifying the AMC size. Viability of E325 was monitored via fluorescent staining, revealing either lack of or minimal stress during or after encapsulation. Proliferation of E325 within AMCs, followed by their subsequent release, and colonization activities within confines of apple flowers were studied under different encapsulation conditions using rfp-labeled E325 to obtain highly promising results. This study provided a 'proof of concept' of the successful use of a microencapsulated biocontrol agent, E325, against E. amylovora, and could serve as a model for further studies on the development of effective plant disease management strategies.
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Alginate microbeads are complement compatible, in contrast to polycation containing microcapsules, as revealed in a human whole blood model. Acta Biomater 2011; 7:2566-78. [PMID: 21402181 DOI: 10.1016/j.actbio.2011.03.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 02/17/2011] [Accepted: 03/09/2011] [Indexed: 11/23/2022]
Abstract
Alginate microbeads and microcapsules are presently under evaluation for future cell-based therapy. Defining their inflammatory properties with regard to humans is therefore essential. A lepirudine-based human whole blood model was used as an inflammation predictor by measuring complement and leukocyte stimulation. Alginate microbeads were complement-compatible since they did not activate complement as measured by the soluble terminal complement complex (sTCC), Bb or the anaphylatoxins C3a and C5a. In addition, alginate microbeads were free of surface adherent leukocytes. In contrast, microcapsules containing poly-L-lysine (PLL) induced elevated levels of sTCC, Bb, C3a and C5a, surface active C3 convertase and leukocyte adhesion. The soluble PLL induced elevated levels of sTCC and up-regulated leukocyte CD11b expression. PMCG microcapsules containing poly(methylene-co-guanidine) complexed with sodium alginate and cellulose sulfate triggered a fast sTCC response and C3 deposition. The PMCG microcapsules were still less activating than PLL-containing microcapsules as a function of time. The amounts of anaphylatoxins C3a and C5a were diminished by the PMCG microcapsules, whereas leukocyte adherence demonstrated surface activating properties. We propose the whole blood model as an important tool for measuring bioincompatibility of microcapsules and microbeads for future applications as well as determining the mechanisms leading to inflammatory reactions.
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Qi M, Lacik I, Kolláriková G, Strand BL, Formo K, Wang Y, Marchese E, Mendoza-Elias JE, Kinzer KP, Gatti F, Paushter D, Patel S, Oberholzer J. A recommended laparoscopic procedure for implantation of microcapsules in the peritoneal cavity of non-human primates. J Surg Res 2011; 168:e117-23. [PMID: 21435661 PMCID: PMC3661273 DOI: 10.1016/j.jss.2011.01.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Revised: 01/11/2011] [Accepted: 01/20/2011] [Indexed: 11/15/2022]
Abstract
BACKGROUND The anatomical spatial distribution of microencapsulated islets transplanted into the peritoneal cavity of large animals remains a relatively unexplored area of study. In this study, we developed a new implantation approach using laparoscopy in order to avoid microcapsule amalgamation. This approach constitutes a clinically relevant method, which can be used to evaluate the distribution and in vivo biocompatibility of various types of transplanted microcapsules in the future. MATERIALS AND METHODS Two healthy baboons were implanted intraperitoneally with microencapsulated islets through mini-laparotomy and observed at 76 d after implantation. Nine baboons underwent laparoscopic implantation of approximately 80,000 empty microcapsules. Microcapsule distribution was observed by laparoscopic camera during and after implantation at 1, 2, and 4 wk. At each time point, microcapsules were retrieved and evaluated with brightfield microscopy and histologic analysis. RESULTS Mini-laparotomic implantation resulted in microcapusle aggregation in both baboons. In contrast, laparoscopic implantation resulted in even distribution of microcapsules throughout the peritoneum without sedimentation to the Douglas space in all animals. In eight out of nine animals, retrieved microcapsules were evenly distributed in the peritoneal cavity and presented with no pericapsular overgrowth and easily washed out during laparoscopic procedure. The one exception was attributed to microcapsule contamination with blood from the abdominal wall following trocar insertion. CONCLUSIONS Laparoscopic implantation of microcapsules in non-human primates can be successfully performed and prevents microcapsule aggregation. Given the current widespread clinical application of laparoscopy, we propose that this presented laparoscopy technique could be applied in future clinical trials of microencapsulated islet transplantation.
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Affiliation(s)
- Meirigeng Qi
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Igor Lacik
- Department of Special Polymers and Biopolymers, Polymer Institute of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Gabriela Kolláriková
- Department of Special Polymers and Biopolymers, Polymer Institute of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Berit L Strand
- Department of Biotechnology, University of Science and Technology (NTNU), Trondheim, Norway
| | - Kjetil Formo
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Yong Wang
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Enza Marchese
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | | | - Katie P. Kinzer
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Francesca Gatti
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Daniel Paushter
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Sonny Patel
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
| | - Jose Oberholzer
- Department of Surgery, University of Illinois at Chicago, Illinois, USA
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Wandrey C, Espinosa D, Rehor A, Hunkeler D. Influence of alginate characteristics on the properties of multi-component microcapsules. J Microencapsul 2010. [DOI: 10.3109/02652040309178349] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- C. Wandrey
- Laboratory of Chemical Biotechnology, Institute of Chemical and Biological Process Science, Swiss Federal Institute of Technology, CH-1015, Lausanne, Switzerland
| | - D. Espinosa
- Laboratory of Chemical Biotechnology, Institute of Chemical and Biological Process Science, Swiss Federal Institute of Technology, CH-1015, Lausanne, Switzerland
| | - A. Rehor
- Institute of Biomedical Technology, Swiss Federal Institute of Technology and University of Zürich, Moussonstrasse 18, CH-8044, Zürich, Switzerland
| | - D. Hunkeler
- AQUA + TECH Specialities S.A., Chemin du Chalet-du-Bac 4, CP28, CH-1283 La Plain, Geneva, CP 117, Switzerland
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Direct effect of alginate purification on the survival of islets immobilized in alginate-based microcapsules. Acta Biomater 2009; 5:3433-40. [PMID: 19520193 DOI: 10.1016/j.actbio.2009.05.029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 04/17/2009] [Accepted: 05/20/2009] [Indexed: 11/22/2022]
Abstract
Alginate purification has been shown to decrease the host immune response to implanted alginate-based microcapsules, but the direct effect of contaminants on islet cell survival remains unknown. Wistar rat islets were immobilized in calcium alginate beads made with crude vs. purified alginate and then incubated in CMRL culture medium. Islet survival was evaluated at 1, 4, 7, 14 and 27 days post-encapsulation. Islet viability was investigated using a dual staining assay (propidium iodide and orange acridine). The islet cell necrosis and the proportion of apoptotic cells were quantified under optical microscopy and with a TUNEL assay, respectively. Islets immobilized in purified alginate were more viable, and had fewer necrotic centers, a smaller area of central necrosis and a lower number of apoptotic cells. At day 14 and 27 post-encapsulation, respectively, 48% and 23% of islets were viable with purified alginate vs. 18% and 8% with crude alginate (p<0.05). At day 14, the surface area of central necrosis and the number of necrotic islets were more important with the impure alginate (65% vs. 45% and 73% vs. 53%, respectively; p<0.05). We conclude that alginate purification improves the survival of islets that are immobilized in alginate-based microcapsules. These findings indicate that caution should be taken in the interpretation of in vivo experiments, as the results could be explained by either a direct effect on islet survival or a modification of the host reaction, or both. Moreover, it suggests that the effect on islet viability should be assessed during the development of biomaterials for cell encapsulation.
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Yang Y, Zhang S, Jones G, Morgan N, El Haj AJ. Phosphorylcholine-Containing Polymers for Use in Cell Encapsulation. ACTA ACUST UNITED AC 2009; 32:91-104. [PMID: 15027804 DOI: 10.1081/bio-120028671] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A model system for encapsulation of pancreatic islets which has potential properties for improving biocompatibility and immunosuppression was investigated. In vitro and in vivo studies have shown that phosphorylcholine-containing polymers have high biocompatibility due to low adsorption of proteins and reduced thrombus formation. Encapsulation of islets isolated from rats with a compound membrane composed of phosphorylcholine-containing polymers and cellulose acetate led to rapid insulin production and diffusion across the membrane in response to glucose challenge. The phosphorylcholine-containing polymer had a molecular weight of about 1.3 x 10(4) Da. The polymer-coated membrane excluded larger molecules such as IgG (molecular weight 150 kDa), thereby acting as a physical immuno-barrier, but allowed smaller molecules such as glucose and insulin to pass through.
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Affiliation(s)
- Ying Yang
- Centre for Science and Technology in Medicine, School of Medicine, Keele University, University Hospital of North Staffordshire, Stoke-on-Trent, Staffs, UK.
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Renken A, Hunkeler D. Polyvinylamine-based capsules: A mechanistic study of the formation using alginate and cellulose sulphate. J Microencapsul 2008; 24:323-36. [PMID: 17497386 DOI: 10.1080/02652040601162350] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Capsules based on sodium alginate (SA) and sodium cellulose sulphate (SCS), have been prepared using polyvinylamines (PVAm) of varying intrinsic viscosities. The resulting capsules are relatively dense in nature, revealing a bursting force which is four times that observed for the classical SA/SCS/polymethylene-co-guanidine chemistry. Molar mass cutoffs were typically in the 10-70 kDa range. A mechanistic study was carried out where the reaction time, ionic strength and pH of the reaction mixture, as well as the stoichiometry of the polyanion blend and the PVAm molar mass were varied. It is postulated that both the SA-PVAm and the SCS-PVAm binary interactions contribute to the mechanical properties and the permeability of the resulting capsules. The polyvinylamine-based chemistry offers interesting alternatives to the PMCG system in that it provides a means to produce capsules at low, or zero, ionic strengths. Subtle changes in the pH, or the SA:SCS ratio, can also be used to tune the bursting force quite sensitively. The most appropriate capsules, for transplantation, would likely be formed at polyanion levels of 1.2 wt% with a PVAm molar mass below 17 kDa.
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Affiliation(s)
- A Renken
- Laboratory of Polyelectrolytes and BioMacromolecules, Swiss Federal Institute of Technology, Lausanne, Switzerland
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Prakash S, Malgorzata Urbanska A. Colon-targeted delivery of live bacterial cell biotherapeutics including microencapsulated live bacterial cells. Biologics 2008; 2:355-78. [PMID: 19707368 PMCID: PMC2721377 DOI: 10.2147/btt.s2372] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
There has been an ample interest in delivery of therapeutic molecules using live cells. Oral delivery has been stipulated as best way to deliver live cells to humans for therapy. Colon, in particular, is a part of gastrointestinal (GI) tract that has been proposed to be an oral targeted site. The main objective of these oral therapy procedures is to deliver live cells not only to treat diseases like colorectal cancer, inflammatory bowel disease, and other GI tract diseases like intestinal obstruction and gastritis, but also to deliver therapeutic molecules for overall therapy in various diseases such as renal failure, coronary heart disease, hypertension, and others. This review provides a comprehensive summary of recent advancement in colon targeted live bacterial cell biotherapeutics. Current status of bacterial cell therapy, principles of artificial cells and its potentials in oral delivery of live bacterial cell biotherapeutics for clinical applications as well as biotherapeutic future perspectives are also discussed in our review.
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Affiliation(s)
- Satya Prakash
- Biomedical Technology and Cell Therapy Research Laboratory, Departments of Biomedical Engineering and Physiology, Artificial Cells and Organs Research Center, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Aleksandra Malgorzata Urbanska
- Biomedical Technology and Cell Therapy Research Laboratory, Departments of Biomedical Engineering and Physiology, Artificial Cells and Organs Research Center, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
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Wang T, Adcock J, Kühtreiber W, Qiang D, Salleng KJ, Trenary I, Williams P. Successful Allotransplantation of Encapsulated Islets in Pancreatectomized Canines for Diabetic Management Without the Use of Immunosuppression. Transplantation 2008; 85:331-7. [DOI: 10.1097/tp.0b013e3181629c25] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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27
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Nahalka J, Dib I, Nidetzky B. Encapsulation of Trigonopsis variabilis D-amino acid oxidase and fast comparison of the operational stabilities of free and immobilized preparations of the enzyme. Biotechnol Bioeng 2008; 99:251-60. [PMID: 17680679 DOI: 10.1002/bit.21579] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A one-step procedure of immobilizing soluble and aggregated preparations of D-amino acid oxidase from Trigonopsis variabilis (TvDAO) is reported where carrier-free enzyme was entrapped in semipermeable microcapsules produced from the polycation poly(methylene-co-guanidine) in combination with CaCl2 and the polyanions alginate and cellulose sulfate. The yield of immobilization, expressed as the fraction of original activity present in microcapsules, was approximately 52 +/- 5%. The effectiveness of the entrapped oxidase for O2-dependent conversion of D-methionine at 25 degrees C was 85 +/- 10% of the free enzyme preparation. Because continuous spectrophotometric assays are generally not well compatible with insoluble enzymes, we employed a dynamic method for the rapid in situ estimation of activity and relatedly, stability of free and encapsulated oxidases using on-line measurements of the concentration of dissolved O2. Integral and differential modes of data acquisition were utilized to examine cases of fast and slow inactivation of the enzyme, respectively. With a half-life of 60 h, encapsulated TvDAO was approximately 720-fold more stable than the free enzyme under conditions of bubble aeration at 25 degrees C. The soluble oxidase was stabilized by added FAD only at temperatures of 35 degrees C or greater.
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Affiliation(s)
- Jozef Nahalka
- Research Centre Applied Biocatalysis, Petersgasse 14, A-8010 Graz, Austria
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28
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Vikartovská A, Bučko M, Mislovičová D, Pätoprstý V, Lacík I, Gemeiner P. Improvement of the stability of glucose oxidase via encapsulation in sodium alginate–cellulose sulfate–poly(methylene-co-guanidine) capsules. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2007.06.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hartig SM, Carlesso G, Davidson JM, Prokop A. Development of Improved Nanoparticulate Polyelectrolyte Complex Physicochemistry by Nonstoichiometric Mixing of Polyions with Similar Molecular Weights. Biomacromolecules 2007; 8:265-72. [PMID: 17206816 DOI: 10.1021/bm0604754] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Water-based, biodegradable polyelectrolyte complex dispersions (PECs) prepared by mixing oppositely charged polyions are advantageous drug delivery systems due to constituent biocompatibility and nanoparticulate architectures. Reaction phase environmental parameters dictate PEC physicochemical properties, and specifically, complexation between polyelectrolytes having significantly different molecular weights leads to formation of water-insoluble aggregates. Starting with this fact, four-component similar and dissimilar molecular weight PEC chemistries were applied and compared with and without frequency-induced dispergation. The goal was to define nanoparticulate PEC systems with desirable characteristics for use in biological systems. Results show PEC formulations from precursors with similar low molecular weights yielded dispersions with suitable physicochemical characteristics, as verified by photon correlation spectroscopy and TEM, presumably due to efficient ion pairing. Similar low molecular weight PECs fabricated with dispergation exhibited pH-independent stability, as validated by charge and size measurements. These physicochemical advantages lead to an ideal delivery platform.
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Affiliation(s)
- Sean M Hartig
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, USA
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Roth DJ, Jansen ED, Powers AC, Wang TG. A novel method of monitoring response to islet transplantation: bioluminescent imaging of an NF-kB transgenic mouse model. Transplantation 2006; 81:1185-90. [PMID: 16641606 DOI: 10.1097/01.tp.0000203808.84963.13] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Transplantation of encapsulated pancreatic islets is a novel therapeutic approach for the treatment of Type 1 diabetes mellitus that has the potential to circumvent both a limited islet supply and immunosuppression. Current methods for scoring the biocompatibility of the alginate-based capsules that sequester Islets of Langerhans include fabrication and implantation into the peritoneal cavity of mice, incubation, retrieval via peritoneal lavage, and observation of the number of cells or cell layers surrounding the capsules. This method allows only one data point to be obtained per animal. We describe a method to measure biocompatibility real time and in situ. This method of monitoring immune response using bioluminescent technology and a nuclear factor-kappa beta (NF-kB) sensitive transgenic mouse model allows many data points to be acquired per animal, reduces the number of animals required to obtain statistically significant immune response data over time, and in turn reduces error associated with animal variability. NF-kB is a transcription factor that coordinates the inflammatory and wound healing cascades by initiating the transcription of cytokines, chemokines, adhesion molecules, and proinflammatory genes. METHODS Inflammation after the transplantation of five types of capsules was monitored for 6 six weeks after transplantation into the dorsal-cervical fat pad. RESULTS Bioluminescence over 6-week time period: Capsule group 1.0+/-.00 normalized units, Bead group 1.3+/-.26 normalized units, No coat group .96+/-.48 normalized units, Sham group .96+/-.00 normalized units, Control group .17+/-.11 normalized units. CONCLUSIONS This imaging modality was able to detect statistically significant differences in NF-kB activity between pre- and postoperative data points per mouse. It was also able to discern an unexpected increase in NF-kB activity due to capsule size instead of capsule wall composition over a 6-week time period.
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Affiliation(s)
- David J Roth
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA.
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31
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Diekmann S, Bader A, Schmitmeier S. Present and Future Developments in Hepatic Tissue Engineering for Liver Support Systems : State of the art and future developments of hepatic cell culture techniques for the use in liver support systems. Cytotechnology 2006; 50:163-79. [PMID: 19003077 PMCID: PMC3476010 DOI: 10.1007/s10616-006-6336-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Accepted: 01/03/2006] [Indexed: 12/23/2022] Open
Abstract
The liver is the most important organ for the biotransformation of xenobiotics, and the failure to treat acute or acute-on-chronic liver failure causes high mortality rates in affected patients. Due to the lack of donor livers and the limited possibility of the clinical management there has been growing interest in the development of extracorporeal liver support systems as a bridge to liver transplantation or to support recovery during hepatic failure. Earlier attempts to provide liver support comprised non-biological therapies based on the use of conventional detoxification procedures, such as filtration and dialysis. These techniques, however, failed to meet the expected efficacy in terms of the overall survival rate due to the inadequate support of several essential liver-specific functions. For this reason, several bioartificial liver support systems using isolated viable hepatocytes have been constructed to improve the outcome of treatment for patients with fulminant liver failure by delivering essential hepatic functions. However, controlled trials (phase I/II) with these systems have shown no significant survival benefits despite the systems' contribution to improvements in clinical and biochemical parameters. For the development of improved liver support systems, critical issues, such as the cell source and culture conditions for the long-term maintenance of liver-specific functions in vitro, are reviewed in this article. We also discuss aspects concerning the performance, biotolerance and logistics of the selected bioartificial liver support systems that have been or are currently being preclinically and clinically evaluated.
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Affiliation(s)
- Sonja Diekmann
- Center for Biotechnology and Biomedicine, Cell Techniques and Applied Stem Cell Biotechnology, University of Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany
| | - Augustinus Bader
- Center for Biotechnology and Biomedicine, Cell Techniques and Applied Stem Cell Biotechnology, University of Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany
| | - Stephanie Schmitmeier
- Center for Biotechnology and Biomedicine, Cell Techniques and Applied Stem Cell Biotechnology, University of Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany
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Silva AI, de Matos AN, Brons IG, Mateus M. An overview on the development of a bio-artificial pancreas as a treatment of insulin-dependent diabetes mellitus. Med Res Rev 2006; 26:181-222. [PMID: 16342061 DOI: 10.1002/med.20047] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper presents the concept and most of the research undertaken all over the world for the development of a bio-artificial pancreas (BAP) device over the last 30 years. The devices studied, meant to mimic the insulin secretion of the natural organ, were diverse and have been reviewed. Allogeneic or xenogeneic cells or cell clusters have been separated from the host's immune system by synthetic biocompatible semipermeable membranes to prevent the need, of the host, for immune-suppressing regimens. The biocompatible polymer used as a barrier and its intrinsic characteristics, the cell immobilization or suspension media, the existence or not of co-immobilized molecules or cells, the number of devices used and the implantation site, were addressed.
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Affiliation(s)
- Ana Isabel Silva
- Centro de Engenharia Biológica e Química, Instituto Superior Técnico, Lisboa, Portugal
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33
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Lacík I. Polymer Chemistry in Diabetes Treatment by Encapsulated Islets of Langerhans: Review to 2006. Aust J Chem 2006. [DOI: 10.1071/ch06197] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Polymeric materials have been successfully used in numerous medical applications because of their diverse properties. For example, development of a bioartificial pancreas remains a challenge for polymer chemistry. Polymers, as a form of various encapsulation device, have been proposed for designing the semipermeable membrane capable of long-term immunoprotection of transplanted islets of Langerhans, which regulate the blood glucose level in a diabetic patient. This review describes the current situation in the field, discussing aspects of material selection, encapsulation devices, and encapsulation protocols. Problems and unanswered questions are emphasized to illustrate why clinical therapies with encapsulated islets have not been realized, despite intense activity over the past 15 years. The review was prepared with the goal to address professionals in the field as well as the broad polymer community to help in overcoming final barriers to the clinical phase for transplantation of islets of Langerhans encapsulated in a polymeric membrane.
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Abstract
Diabetes remains a devastating disease, with tremendous cost in terms of human suffering and healthcare expenditures. A bioartificial pancreas has the potential as a promising approach to preventing or reversing complications associated with this disease. Bioartificial pancreatic constructs are based on encapsulation of islet cells with a semipermeable membrane so that cells can be protected from the host's immune system. Encapsulation of islet cells eliminates the requirement of immunosuppressive drugs, and offers a possible solution to the shortage of donors as it may allow the use of animal islets or insulin-producing cells engineered from stem cells. During the past 2 decades, several major approaches for immunoprotection of islets have been studied. The microencapsulation approach is quite promising because of its improved diffusion capacity, and technical ease of transplantation. It has the potential for providing an effective long-term treatment or cure of Type 1 diabetes.
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Affiliation(s)
- Seda Kizilel
- Section of Transplantation, Department of Surgery, The University of Chicago, Chicago, Illinois, USA
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35
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Breguet V, Gugerli R, Pernetti M, von Stockar U, Marison IW. Formation of microcapsules from polyelectrolyte and covalent interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:9764-72. [PMID: 16207064 DOI: 10.1021/la0512796] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A new approach combining electrostatic and covalent bonds was established for the formation of resistant capsules with long-term stability under physiological conditions. Three kinds of interactions were generated in the same membrane: (1) electrostatic bonds between alginate and poly-L-lysine (PLL), (2) covalent bonds (amides) between propylene-glycol-alginate (PGA) and PLL, and (3) covalent bonds (amides) between BSA and PGA. Down-scaling of the capsules size (< or =1 mm diameter) with a jet break-up technology was achieved by modifying the rheological properties of the polymer solution. Viscosity of the PGA solution was reduced by 95% with four successive pH stabilizations (pH 7), while filtration (0.2 microm) and sterilization was possible. Covalent bond formation was initiated by addition of NaOH (pH 11) using a transacylation reaction. Kinetics of the chemical reaction (pH 11) were simulated by two mathematical models and adapted in order to preserve immobilization of animal cells. It was demonstrated that diffusion of NaOH in the absence of BSA resulted in gelation of 94% of the bead and death of 94% of the cells after 10 s reaction. By addition of BSA only 46% of the cells were killed within the same reaction time (10 s). Mechanical resistance of this new type of capsule could be increased 5-fold over the standard polyelectrolytic system (PLL-alginate). Encapsulated CHO cells were successfully cultivated for 1 month in a repetitive batch mode, with the mechanical resistance of the capsules decreasing by only 10% during this period. The combination of a synthetic and natural protein resulted in enhanced stability toward culture medium and proteolytic enzymes (250%).
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Affiliation(s)
- Véronique Breguet
- Laboratory of Chemical and Biochemical Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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36
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Ponce S, Orive G, Gascón AR, Hernández RM, Pedraz JL. Microcapsules prepared with different biomaterials to immobilize GDNF secreting 3T3 fibroblasts. Int J Pharm 2005; 293:1-10. [PMID: 15778039 DOI: 10.1016/j.ijpharm.2004.10.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Revised: 07/20/2004] [Accepted: 10/29/2004] [Indexed: 11/16/2022]
Abstract
Cell microencapsulation represents a promising tool for the treatment of many central nervous system (CNS) diseases such as Parkinson's disease. In this technology, cells are surrounded by a semipermeable membrane which protects them from mechanical stress and isolates them from host's immune response. However, if the future clinical application of this strategy is wanted, many challenges remain including the improvement of the mechanical resistance of the microcapsules and the optimization of the intracapsular microenvironment conditions. In this way, the selection of the matrix is essential because the morphological and the physiological behavior of the cells depend on the interactions between the matrix and the enclosed cells. Assuming these considerations, three types of microcapsules elaborated with four different polymers: alginate, cellulose sulfate, agarose and pectin have been fabricated and compared in order to evaluate some key properties such as morphology, size and mechanical stability. Furthermore, GDNF secreting Fischer rat 3T3 fibroblasts were immobilized in each type of capsule and the viability and neurotrophic factor release was determinated. Results showed that the alginate and pectin microcapsules were the most resistant devices, maintaining an adequate microenvironment for the enclosed cells. In contrast, cells entrapped in alginate-cellulose sulfate matrices presented the lowest mechanical resistance, cell viability and GDNF production.
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Affiliation(s)
- S Ponce
- Laboratory of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of the Basque Country, Vitoria-Gasteiz, Spain
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Bučko M, Vikartovská A, Lacík I, Kolláriková G, Gemeiner P, Pätoprstý V, Brygin M. Immobilization of a whole-cell epoxide-hydrolyzing biocatalyst in sodium alginate−cellulose sulfate−poly(methylene-co-guanidine) capsules using a controlled encapsulation process. Enzyme Microb Technol 2005. [DOI: 10.1016/j.enzmictec.2004.07.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Zhang LY, Yao SJ, Guan YX. Effects of poly(methylene-co-guanidine) on microbial growth in an alginate/cellulose sulphate–CaCl2/poly(methylene-co-guanidine) capsule system. Process Biochem 2005. [DOI: 10.1016/j.procbio.2003.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lekka M, Sainz-Serp D, Kulik AJ, Wandrey C. Hydrogel microspheres: influence of chemical composition on surface morphology, local elastic properties, and bulk mechanical characteristics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:9968-9977. [PMID: 15518482 DOI: 10.1021/la048389h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Hydrogel microspheres, beads, and capsules of uniform size, differing in their chemical composition, have been prepared by electrostatic complex formation of sodium alginate with divalent cations and polycations. These have served as model spheres to study the influence of the chemical composition on both surface characteristics and bulk mechanical properties. Resistance to compression experiments yielding the compression work clearly identified differences as a function of the composition, with forces at maximal compression in the range of 34-455 mN. The suitability and informative value of atomic force microscopy have been confirmed for the case where surface characterization is performed in a liquid environment equivalent to physiological conditions. Surface imaging and mechanical response to indentation revealed different average surface roughness and Young's moduli for all hydrogel types ranging from 0.9 to 14.4 nm and from 0.4 to 440 kPa, respectively. The hydrogels exhibited pure elastic behavior. Despite a relatively high standard deviation, resulting from both surface and batch heterogeneity, nonoverlapping ranges of Young's moduli were reproducibly identified for the selected model spheres. The findings indicate the reliability of contact mode atomic force microscopy to quantify local surface properties, which may have an impact on the biocompatibility of alginate-based hydrogel materials of different composition and conditions of preparation. Moreover, it seems that local elastic properties and bulk mechanical characteristics are subject to analogous composition influences.
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Affiliation(s)
- Malgorzata Lekka
- The Henryk Niewodniczanki Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
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Dai Z, Heilig A, Zastrow H, Donath E, Möhwald H. Novel Formulations of Vitamins and Insulin by Nanoengineering of Polyelectrolyte Multilayers around Microcrystals. Chemistry 2004; 10:6369-74. [PMID: 15532049 DOI: 10.1002/chem.200400579] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Microcapsules loaded with vitamin K3 (VK3), biotin, or insulin were prepared by using a novel coating technology based on the layer-by-layer (LbL) deposition of oppositely charged polyelectrolytes onto microcrystal templates. This produced multilayered, polymeric shells of varying thickness around the crystalline cores. Dissolution of the core material (VK3 with ethanol, biotin with basic solution, and insulin with acidic solution), resulted in its release through the shells. Microelectrophoresis was employed to monitor the microcrystal coating process; confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM) were used to verify multilayer coating and the formation of hollow polymer shells following removal of the microcrystal templates. The release rates of both VK3 and insulin decreased as the wall thickness (the number of polyelectrolyte layers deposited onto the microcrystal cores), increased. The release time could be varied by a factor of more than ten, depending on the number of polyelectrolyte layers applied. Following the addition of 70 mass % ethanol, the solubility of VK3 increased by as much as 170-fold, resulting in an increased rate of VK3 release. By selecting appropriate polymer materials for the shells, and by controlling the number of polyelectrolyte layers applied, shells of various thickness, stiffness, aqueous solubility, dispersibility, biocompatibility, and permeability can be constructed.
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Affiliation(s)
- Zhifei Dai
- Max-Planck Institute of Colloids and Interfaces, 14476 Golm/Potsdam, Germany.
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41
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Anderson RA, Feathergill K, Diao XH, Chany C, Rencher WF, Zaneveld LJD, Waller DP. Contraception by Ushercell™ (cellulose sulfate) in formulation: duration of effect and dose effectiveness. Contraception 2004; 70:415-22. [PMID: 15504382 DOI: 10.1016/j.contraception.2004.05.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2004] [Revised: 05/12/2004] [Accepted: 05/24/2004] [Indexed: 11/15/2022]
Abstract
This study evaluated contraception by formulated Ushercell, a uniquely high-molecular-weight form of cellulose sulfate, in the rabbit. Variables included (1) dose effectiveness, (2) duration of effectiveness, and (3) formulation excipients. Vaginally applied carboxymethyl-cellulose-based Ushercell gel is contraceptive. A 6% gel is active for at least 18 h; partial activity is observed for at least 24 h. With an application-insemination interval of 0.5 h, Ushercell as low as 0.1% is contraceptive. Contraception is incomplete with 2% Ushercell and an application-insemination interval of 24 h. Ushercell formulations containing a relatively high concentration of Carbopol are ineffective contraceptives, whether the gel is applied before insemination or is premixed with spermatozoa before insemination. Contraceptive activity is restored in Ushercell formulations with lower Carbopol content. This study shows that formulated Ushercell is an effective, long-lasting contraceptive and, hence, is bioavailable when vaginally applied. Activity is dependent on the type and relative concentration of formulation excipients. These data support a projected successful outcome of further clinical trials.
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Affiliation(s)
- Robert A Anderson
- Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, IL 60612, USA.
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42
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Desai TA, West T, Cohen M, Boiarski T, Rampersaud A. Nanoporous microsystems for islet cell replacement. Adv Drug Deliv Rev 2004; 56:1661-73. [PMID: 15350295 DOI: 10.1016/j.addr.2003.11.006] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2003] [Accepted: 05/15/2004] [Indexed: 11/26/2022]
Abstract
The inadequacy of conventional insulin therapy for the treatment of Type I diabetes has stimulated research on several therapeutic alternatives, including insulin pumps and controlled release systems for insulin. One of the most physiological alternatives to insulin injections is the transplantation of insulin-secreting cells. It is the beta cells of the islets that secrete insulin in response to increasing blood glucose concentrations. Ideally, transplantation of such cells (allografts or xenografts) could restore normoglycemia. However, as with most tissue or cellular transplants, the cellular grafts, particularly xenografts, are subjected to immunorejection in the absence of chronic immunosuppression. Thus, it is of great interest to develop new technologies that may be used for islet cell replacement. This research proposal describes a new approach to cellular delivery based on micro- and nanotechnology. Utilizing this approach, nanoporous biocapsules are bulk and surface micromachined to present uniform and well-controlled pore sizes as small as 7 nm, tailored surface chemistries, and precise microarchitectures, in order to provide immunoisolating microenvironments for cells. Such a design may overcome some of the limitations associated with conventional encapsulation and delivery technologies, including chemical instabilities, material degradation or fracture, and broad membrane pore sizes.
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Affiliation(s)
- Tejal A Desai
- Department of Biomedical Engineering, Boston University, 44 Cummington Street, Boston, MA 02215 USA.
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43
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Sakai S, Ono T, Ijima H, Kawakami K. Modification of porous aminopropyl-silicate microcapsule membrane by electrically-bonded external anionic polymers. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2004; 14:643-52. [PMID: 12903733 DOI: 10.1163/156856203322274905] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Biocompatibility and permeability of a microcapsule membrane governs the function of a microcapsule-shaped bioartificial pancreas. We have previously developed an alginate/sol-gel-synthesized aminopropyl-silicate/alginate microcapsule (Alg/AS/Alg), which had insufficient biocompatibility. The purpose of this study was to investigate whether the biocompatibility could improve by modifying the external surface with other anionic polymers and to investigate an influence of the modification on the permeability of the membrane. Four kinds of anionic polymers, poly(oxyethylene)diglycolic acid (3 kDa), heparin (15 kDa), Alg (54 kDa) and carboxymethylcellulose (CMC, 60 kDa) were used as the external anionic polymers. The heparin-bonded gel bead had the largest resistance to the diffusion of small molecules. The molecular mass cut-off point of 150 kDa required for immunoisolation was maintained for all anionic polymers. Cellular overgrowth to the implanted islet-enclosing microcapsule, a sign of insufficient biocompatibility, was suppressed by altering the external surface material from Alg to CMC. These results suggest that the biocompatibility of the Alg/AS/anionic polymer membrane can be improved by using a biocompatible anionic polymer. At the same time, it is suggested the influence on the permeability has to be investigated to develop an optimal microcapsule for bioartificial pancreas.
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Affiliation(s)
- Shinji Sakai
- Department of Chemical Engineering, Faculty of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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44
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46
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Bünger CM, Gerlach C, Freier T, Schmitz KP, Pilz M, Werner C, Jonas L, Schareck W, Hopt UT, de Vos P. Biocompatibility and surface structure of chemically modified immunoisolating alginate‐PLL capsules. J Biomed Mater Res A 2003; 67:1219-27. [PMID: 14624508 DOI: 10.1002/jbm.a.10094] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Grafting of encapsulated living cells has the potential to cure a wide variety of diseases. Large-scale application of the technique, however, is hampered by insufficient biocompatibility of the capsules. A major factor in the biocompatibility of capsules is inadequate covering of the inflammatory poly-L-lysine (PLL) on the capsules' surface. In the present study, we investigate whether tissue responses against alginate-PLL capsules can be reduced by crosslinking the surface of the capsules with heparin or polyacrylic acid. Our transplant study in rats shows a tissue response composed of fibroblasts and macrophages on alginate-PLL-alginate and alginate-PLL-heparin capsules that was completely absent on alginate-PLL-polyacrylic acid capsules. Atomic force microscopy analyses of the capsules demonstrates that the improved biocompatibility of alginate-PLL-capsules by polyacrylic acid coating should not only be explained by a more adequate binding of PLL but also by the induction of a smoother surface. This study shows for the first time that biologic responses against capsules can be successfully deleted by chemically crosslinking biocompatible molecules on the surface of alginate-PLL capsules.
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Affiliation(s)
- C M Bünger
- Department of Surgery, University of Rostock, Schillingallee 35, 18055 Rostock, Germany
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47
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Angelova N, Hunkeler D. Stability assessment of chitosan-sodium hexametaphosphate capsules. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2002; 12:1207-25. [PMID: 11853387 DOI: 10.1163/156856201753395752] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The assessment of the stability of capsules based on chitosan-sodium hexametaphosphate complex formation has been carried out using two independent methods--compression and osmotic swelling, and the influence of the preparation variables was evaluated. The formulation containing 1.5% core polymer (chitosan) and 1.5% oligophosphate, in the absence of salt or at low ionic strength (0.15% NaCl) was found to provide the best membrane resistance. A higher concentration of cross-linker (2.25%) produced stable capsules only in absence of electrolyte. Mannitol, a porogen added to the preparation solutions, did not affect the stability of the obtained membranes. At elevated polyol (1%) and cross-linker levels (2.25%), and at 0% salt, membranes with decreased elasticity were obtained, having lower compression and osmotic bursting values and lower deformation at the breaking points. A significant influence of salt amount on the capsule stability was also found. This was attributed to changes in the membrane formation process resulting in membranes with different thickness and structure. Membrane compression stability was found to be dependent on the pH of both oligophosphate and chitosan solutions, as well as on the reaction time. The bursting force values decreased for capsule diameters below 1.6 mm. The increased membrane/capsule volume ratio for the small capsules decreased the capsule deformation freedom and caused capsule rupture at low force values. The capsules made at low salt amounts showed very good storage stability over time and at elevated temperatures. The results demonstrated that the capsules could be formulated with controlled properties for various biomedical applications.
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Affiliation(s)
- N Angelova
- Department of Chemistry, Swiss Federal Institute of Technology.
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48
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Abstract
The inadequacy of conventional insulin therapy for the treatment of Type I diabetes has stimulated research on several therapeutic alternatives, including insulin pumps and controlled-release systems for insulin. One of the most physiological alternatives to insulin injections is the transplantation of insulin-secreting cells. It is the beta-cells of the islets that secrete insulin in response to increasing blood glucose concentrations. Ideally, transplantation of such cells (allografts or xenografts) could restore normoglycaemia. However, as with most tissue or cellular transplants, the cellular grafts, particularly xenografts, are subject to immunorejection in the absence of chronic immunosuppression. Thus, it is of great interest to develop new technologies that may be used for insulin delivery or pancreatic cell transplantation. This review describes a new approach to cellular delivery based on micro- and nanotechnology. Utilising this approach, nanoporous biocapsules are bulk and surface micromachined to present uniform and well-controlled pore sizes as small as 7 nm, tailored surface chemistries and precise microarchitectures, in order to provide immunoisolating microenvironments for cells. Such a design may overcome some of the limitations associated with conventional encapsulation and delivery technologies, including chemical instabilities, material degradation or fracture and broad membrane pore sizes.
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Affiliation(s)
- Tejal A Desai
- Department of Biomedical Engineering, Boston University, MA 02215, USA.
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49
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Iskakov RM, Kikuchi A, Okano T. Time-programmed pulsatile release of dextran from calcium-alginate gel beads coated with carboxy-n-propylacrylamide copolymers. J Control Release 2002; 80:57-68. [PMID: 11943387 DOI: 10.1016/s0168-3659(01)00551-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Time-programmed release of macromolecular drugs was achieved by utilization of calcium-alginate gel beads modified with coated copolymer layers. Modified calcium-alginate gel beads coated with poly(carboxy-n-propylacrylamide-co-dimethylacrylamide) [poly(CNPAAm-co-DMAAm)] (22.7 mol% of CNPAAm) of varying coating thickness from 25 to 125 microm were developed as drug carriers. Model macromolecular drugs used were fluorescein isothiocyanate (FITC)-labeled dextrans with different molecular weights ranging from 9400 to 145000. FITC-dextran release was strongly dependent on both copolymer coating thicknesses and the dextran molecular weights. Release of FITC-dextran (MW 9400) followed Fickian diffusion according to t(1/2) dependence, indicating that the drug diffusion is the main driving force for release of dextran MW 9400. Release of higher molecular weight FITC-dextrans (71,00 and 145,00) exhibited a burst-effect preceded by a preset lag time. These release profiles were governed by the dissociation of calcium ions from polyguluronate sequences in alginate molecules along with the diffusion of sodium ions into the gel bead core. This created osmotic pressure inside the gel, inducing breakage of the coated copolymer layer and accelerated drug release. Burst release of macromolecular drugs thus occurred after a certain lag period. The lag time was regulated by the copolymer coat thickness. A pulsatile release of FITC-dextran was demonstrated by combining a series of modified alginate gel beads in a single batch.
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Affiliation(s)
- Rinat M Iskakov
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo 162-8666, Japan
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50
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Abstract
A novel chemical reactor was designed and developed for the continuous high-rate production of uniform capsules. This reactor helps to control precisely the reaction time between the reacting liquids (anion drops and the cation bath, or vice versa), thereby leading to the formation of uniform capsules with walls of identical thickness. In addition, mild tumbling of the capsules during transit through the reactor ensures that every capsule wall is uniformly thick all around.
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Affiliation(s)
- A V Anilkumar
- Center for Microgravity Research and Applications, 1743-B, Vanderbilt University, Nashville, Tennessee 37235, USA.
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