1
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Lopes MM, Oliveira-Paiva CAD, Farinas CS. Modification of pectin/starch-based beads with additives to improve Bacillus subtilis encapsulation for agricultural applications. Int J Biol Macromol 2023; 246:125646. [PMID: 37394222 DOI: 10.1016/j.ijbiomac.2023.125646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/21/2023] [Accepted: 06/29/2023] [Indexed: 07/04/2023]
Abstract
The use of Bacillus as biofertilizer is a sustainable strategy to increase agricultural productivity, but it still requires the development of formulations to protect cells from stressful conditions. Ionotropic gelation using a pectin/starch matrix is a promising encapsulation strategy to achieve this goal. By incorporating additives such as montmorillonite (MMT), attapulgite (ATP), polyethylene glycol (PEG), and carboxymethyl cellulose (CMC), the properties of these encapsulated products could be further improved. In this study, we investigated the influence of these additives on the properties of pectin/starch-based beads for the encapsulation of Bacillus subtilis. FTIR analysis indicated pectin and Ca2+ ions interactions, while the XRD showed good dispersion of clays in the materials. SEM and X-ray microtomography revealed differences in the morphology of the beads due to the use of the additives. The viabilities at the encapsulation were higher than 1010 CFU g-1 for all formulations, with differences in the release profiles. In terms of cell protection, the pectin/starch, pectin/starch-MMT and pectin/starch-CMC formulations showed the highest cell viability after exposure to fungicide, while the pectin/starch-ATP beads showed the best performance after UV exposure. Moreover, all formulations maintained more than 109 CFU g-1 after six months of storage, which meets values required for microbial inoculants.
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Affiliation(s)
- Marina Momesso Lopes
- National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, 13560-970 São Carlos, SP, Brazil; Graduate Program of Biotechnology, Federal University of São Carlos, 13565-905 São Carlos, SP, Brazil
| | | | - Cristiane Sanchez Farinas
- National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, 13560-970 São Carlos, SP, Brazil; Graduate Program of Biotechnology, Federal University of São Carlos, 13565-905 São Carlos, SP, Brazil; Graduate Program of Chemical Engineering, Federal University of São Carlos, 13565-905 Sao Carlos, SP, Brazil.
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2
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Somo SI, Brown JM, Brey EM. Dual Crosslinking of Alginate Outer Layer Increases Stability of Encapsulation System. Front Chem 2020; 8:575278. [PMID: 33282827 PMCID: PMC7688585 DOI: 10.3389/fchem.2020.575278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/21/2020] [Indexed: 01/17/2023] Open
Abstract
The current standard treatment for Type 1 diabetes is the administration of exogenous insulin to manage blood glucose levels. Cellular therapies are in development to address this dependency and allow patients to produce their own insulin. Studies have shown that viable, functional allogenic islets can be encapsulated inside alginate-based materials as a potential treatment for Type 1 diabetes. The capability of these grafts is limited by several factors, among which is the stability and longevity of the encapsulating material in vivo. Previous studies have shown that multilayer Alginate-Poly-L-Ornithine-Alginate (A-PLO-A) microbeads are effective in maintaining cellular function in vivo. This study expands upon the existing encapsulation material by investigating whether covalent crosslinking of the outer alginate layer increases stability. The alginate comprising the outer layer was methacrylated, allowing it to be covalently crosslinked. Microbeads with a crosslinked outer layer exhibited a consistent outer layer thickness and increased stability when exposed to chelating agents in vitro. The outer layer was maintained in vivo even in the presence of a robust inflammatory response. The results demonstrate a technique for generating A-PLO-A with a covalently crosslinked outer layer.
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Affiliation(s)
- Sami I. Somo
- Biomedical Engineering Department, Illinois Institute of Technology, Chicago, IL, United States
| | - Jacob M. Brown
- Biomedical Engineering Department, University of Texas at San Antonio, San Antonio, TX, United States
| | - Eric M. Brey
- Biomedical Engineering Department, University of Texas at San Antonio, San Antonio, TX, United States
- *Correspondence: Eric M. Brey
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3
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Szabó L, Noverraz F, Gerber‐Lemaire S. Multicomponent Alginate‐Derived Hydrogel Microspheres Presenting Hybrid Ionic‐Covalent Network and Drug Eluting Properties. Helv Chim Acta 2020. [DOI: 10.1002/hlca.202000115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Luca Szabó
- Institute of Chemical Sciences and Engineering, Group for Functionalized Biomaterials Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC SCI-SB-SG Station 6 CH-1015 Lausanne Switzerland
| | - François Noverraz
- Institute of Chemical Sciences and Engineering, Group for Functionalized Biomaterials Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC SCI-SB-SG Station 6 CH-1015 Lausanne Switzerland
| | - Sandrine Gerber‐Lemaire
- Institute of Chemical Sciences and Engineering, Group for Functionalized Biomaterials Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC SCI-SB-SG Station 6 CH-1015 Lausanne Switzerland
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4
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Perera D, Medini M, Seethamraju D, Falkowski R, White K, Olabisi RM. The effect of polymer molecular weight and cell seeding density on viability of cells entrapped within PEGDA hydrogel microspheres. J Microencapsul 2018; 35:475-481. [DOI: 10.1080/02652048.2018.1526341] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Davina Perera
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
| | - Michael Medini
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
| | | | - Ron Falkowski
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
| | - Kristopher White
- Chemical and Biochemical Engineering, Rutgers University, New Brunswick, NJ, USA
| | - Ronke M. Olabisi
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
- Institute of Advanced Materials, Devices and Nanotechnology, Rutgers University, New Brunswick, NJ, USA
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5
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Abstract
The principle of immunoisolation of cells is based on encapsulation of cells in immunoprotective but semipermeable membranes that protect cells from hazardous effects of the host immune system but allows ingress of nutrients and outgress of therapeutic molecules. The technology was introduced in 1933 but has only received its deserved attention for its therapeutic application for three decades now.In the past decade important advances have been made in creating capsules that provoke minimal or no inflammatory responses. There are however new emerging challenges. These challenges relate to optimal nutrition and oxygen supply as well as standardization and documentation of capsule properties.It is concluded that the proof of principle of applicability of encapsulated grafts for treatment of human disease has been demonstrated and merits optimism about its clinical potential. Further innovation requires a much more systematic approach in identifying crucial properties of capsules and cellular grafts to allow sound interpretations of the results.
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Affiliation(s)
- Paul de Vos
- Division of Immuno-Endocrinology, Departments of Pathology and Laboratory Medicine, University of Groningen, Groningen, Groningen, The Netherlands.
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6
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Passemard S, Szabó L, Noverraz F, Montanari E, Gonelle-Gispert C, Bühler LH, Wandrey C, Gerber-Lemaire S. Synthesis Strategies to Extend the Variety of Alginate-Based Hybrid Hydrogels for Cell Microencapsulation. Biomacromolecules 2017; 18:2747-2755. [PMID: 28742341 DOI: 10.1021/acs.biomac.7b00665] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The production of hydrogel microspheres (MS) for cell immobilization, maintaining the favorable properties of alginate gels but presenting enhanced performance in terms of in vivo durability and physical properties, is desirable to extend the therapeutic potential of cell transplantation. A novel type of hydrogel MS was produced by straightforward functionalization of sodium alginate (Na-alg) with heterotelechelic poly(ethylene glycol) (PEG) derivatives equipped with either end thiol or 1,2-dithiolane moieties. Activation of the hydroxyl moieties of the alginate backbone in the form of imidazolide intermediate allowed for fast conjugation to PEG oligomers through a covalent carbamate linkage. Evaluation of the modified alginates for the preparation of MS combining fast ionic gelation ability of the alginate carboxylate groups and slow covalent cross-linking provided by the PEG-end functionalities highlighted the influence of the chemical composition of the PEG-grafting units on the physical characteristics of the MS. The mechanical properties of the MS (resistance and shape recovery) and durability of PEG-grafted alginates in physiological environment can be adjusted by varying the nature of the end functionalities and the length of the PEG chains. In vitro cell microencapsulation studies and preliminary in vivo assessment suggested the potential of these hydrogels for cell transplantation applications.
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Affiliation(s)
- Solène Passemard
- Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LSPN, Station 6, CH-1015 Lausanne, Switzerland
| | - Luca Szabó
- Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LSPN, Station 6, CH-1015 Lausanne, Switzerland
| | - François Noverraz
- Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LSPN, Station 6, CH-1015 Lausanne, Switzerland
| | - Elisa Montanari
- University Hospital of Geneva, Surgical Research Unit , CMU-1, rue Gabrielle-Perret-Gentil, CH-1211 Geneva, Switzerland
| | - Carmen Gonelle-Gispert
- University Hospital of Geneva, Surgical Research Unit , CMU-1, rue Gabrielle-Perret-Gentil, CH-1211 Geneva, Switzerland
| | - Léo H Bühler
- University Hospital of Geneva, Surgical Research Unit , CMU-1, rue Gabrielle-Perret-Gentil, CH-1211 Geneva, Switzerland
| | - Christine Wandrey
- Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LSPN, Station 6, CH-1015 Lausanne, Switzerland
| | - Sandrine Gerber-Lemaire
- Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , EPFL SB ISIC LSPN, Station 6, CH-1015 Lausanne, Switzerland
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7
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Inhibition of HeLa cell growth by doxorubicin-loaded and tuftsin-conjugated arginate-PEG microparticles. Bioact Mater 2017; 3:48-54. [PMID: 29744441 PMCID: PMC5935659 DOI: 10.1016/j.bioactmat.2017.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/26/2017] [Indexed: 11/25/2022] Open
Abstract
In order to improve the release pattern of chemotherapy drug and reduce the possibility of drug resistance, poly(ethylene glycol amine) (PEG)-modified alginate microparticles (ALG-PEG MPs) were developed then two different mechanisms were employed to load doxorubicin (Dox): 1) forming Dox/ALG-PEG complex by electrostatic attractions between unsaturated functional groups in Dox and ALG-PEG; 2) forming Dox-ALG-PEG complex through EDC-reaction between the amino and carboxyl groups in Dox and ALG, respectively. Additionally, tuftsin (TFT), a natural immunomodulation peptide, was conjugated to MPs in order to enhance the efficiency of cellular uptake. It was found that the Dox-ALG-PEG-TFT MPs exhibited a significantly slower release of Dox than Dox/ALG-PEG-TFT MPs in neutral medium, suggesting the role of covalent bonding in prolonging Dox retention. Besides, the release of Dox from these MPs was pH-sensitive, and the release rate was observably increased at pH 6.5 compared to the case at pH 7.4. Compared with Dox/ALG-PEG MPs and Dox-ALG-PEG MPs, their counterparts further conjugated with TFT more efficiently inhibited the growth of HeLa cells over a period of 48 h, implying the effectiveness of TFT in enhancing cellular uptake of MPs. Over a period of 48 h, Dox-ALG-PEG-TFT MPs inhibited the growth of HeLa cells less efficiently than Dox/ALG-PEG-TFT MPs but the difference was not significant (p > 0.05). In consideration of the prolonged and sustained release of Dox, Dox-ALG-PEG-TFT MPs possess the advantages for long-term treatment. Dox-ALG-PEG-TFT exhibited slower release of Dox than Dox/ALG-PEG-TFT. Release of Dox from Dox-ALG-PEG-TFT and Dox/ALG-PEG-TFT was pH-sensitive. Further conjugation with TFT enhanced the efficiency of Dox/ALG-PEG and Dox-ALG-PEG in inhibiting HeLa cell growth. Dox-ALG-PEG-TFT MPs possess the advantages for long-term treatment over Dox/ALG-PEG-TFT MPs.
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8
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Ryskulova K, Rao Gulur Srinivas A, Kerr-Phillips T, Peng H, Barker D, Travas-Sejdic J, Hoogenboom R. Multiresponsive Behavior of Functional Poly(p-phenylene vinylene)s in Water. Polymers (Basel) 2016; 8:E365. [PMID: 30974643 PMCID: PMC6432201 DOI: 10.3390/polym8100365] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 09/29/2016] [Accepted: 10/10/2016] [Indexed: 12/12/2022] Open
Abstract
The multiresponsive behavior of functionalized water-soluble conjugated polymers (CPs) is presented with potential applications for sensors. In this study, we investigated the aqueous solubility behavior of water-soluble CPs with high photoluminescence and with a particular focus on their pH and temperature responsiveness. For this purpose, two poly(phenylene vinylene)s (PPVs)-namely 2,5-substituted PPVs bearing both carboxylic acid and methoxyoligoethylene glycol units-were investigated, with different amount of carboxylic acid units. Changes in the pH and temperature of polymer solutions led to a response in the fluorescence intensity in a pH range from 3 to 10 and for temperatures ranging from 10 to 85 °C. Additionally, it is demonstrated that the polymer with the largest number of carboxylic acid groups displays upper critical solution temperature (UCST)-like thermoresponsive behavior in the presence of a divalent ion like Ca2+. The sensing capability of these water-soluble PPVs could be utilized to design smart materials with multiresponsive behavior in biomedicine and soft materials.
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Affiliation(s)
- Kanykei Ryskulova
- Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Faculty of Science, Ghent University, Krijgslaan 281 S4, Ghent B-9000, Belgium.
| | - Anupama Rao Gulur Srinivas
- Polymer Electronics Research Center, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
| | - Thomas Kerr-Phillips
- Polymer Electronics Research Center, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
| | - Hui Peng
- Key Laboratory of Polarized Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200062, China.
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, Shanxi, China.
| | - David Barker
- Polymer Electronics Research Center, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | - Jadranka Travas-Sejdic
- Polymer Electronics Research Center, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
| | - Richard Hoogenboom
- Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Faculty of Science, Ghent University, Krijgslaan 281 S4, Ghent B-9000, Belgium.
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9
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Mahou R, Passemard S, Carvello M, Petrelli A, Noverraz F, Gerber-Lemaire S, Wandrey C. Contribution of polymeric materials to progress in xenotransplantation of microencapsulated cells: a review. Xenotransplantation 2016; 23:179-201. [PMID: 27250036 DOI: 10.1111/xen.12240] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 05/09/2016] [Indexed: 12/13/2022]
Abstract
Cell microencapsulation and subsequent transplantation of the microencapsulated cells require multidisciplinary approaches. Physical, chemical, biological, engineering, and medical expertise has to be combined. Several natural and synthetic polymeric materials and different technologies have been reported for the preparation of hydrogels, which are suitable to protect cells by microencapsulation. However, owing to the frequent lack of adequate characterization of the hydrogels and their components as well as incomplete description of the technology, many results of in vitro and in vivo studies appear contradictory or cannot reliably be reproduced. This review addresses the state of the art in cell microencapsulation with special focus on microencapsulated cells intended for xenotransplantation cell therapies. The choice of materials, the design and fabrication of the microspheres, as well as the conditions to be met during the cell microencapsulation process, are summarized and discussed prior to presenting research results of in vitro and in vivo studies. Overall, this review will serve to sensitize medically educated specialists for materials and technological aspects of cell microencapsulation.
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Affiliation(s)
- Redouan Mahou
- Interfaculty Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Institute for Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Solène Passemard
- Interfaculty Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Michele Carvello
- Department of Surgery, San Raffaele Scientific Institute, Milan, Italy
| | | | - François Noverraz
- Interfaculty Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sandrine Gerber-Lemaire
- Interfaculty Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Christine Wandrey
- Interfaculty Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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10
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Kumari J, Karande AA, Kumar A. Combined Effect of Cryogel Matrix and Temperature-Reversible Soluble-Insoluble Polymer for the Development of in Vitro Human Liver Tissue. ACS APPLIED MATERIALS & INTERFACES 2016; 8:264-277. [PMID: 26654271 DOI: 10.1021/acsami.5b08607] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hepatic cell culture on a three-dimensional (3D) matrix or as a hepatosphere appears to be a promising in vitro biomimetic system for liver tissue engineering applications. In this study, we have combined the concept of a 3D scaffold and a spheroid culture to develop an in vitro model to engineer liver tissue for drug screening. We have evaluated the potential of poly(ethylene glycol)-alginate-gelatin (PAG) cryogel matrix for in vitro culture of human liver cell lines. The synthesized cryogel matrix has a flow rate of 7 mL/min and water uptake capacity of 94% that enables easy nutrient transportation in the in vitro cell culture. Young's modulus of 2.4 kPa and viscoelastic property determine the soft and elastic nature of synthesized cryogel. Biocompatibility of PAG cryogel was evaluated through MTT assay of HepG2 and Huh-7 cells on matrices. The proliferation and functionality of the liver cells were enhanced by culturing hepatic cells as spheroids (hepatospheres) on the PAG cryogel using temperature-reversible soluble-insoluble polymer, poly(N-isopropylacrylamide) (PNIPAAm). Pore size of the cryogel above 100 μm modulated spheroid size that can prevent hypoxia condition within the spheroid culture. Both the hepatic cells have shown a significant difference (P < 0.05) in terms of cell number and functionality when cultured with PNIPAAm. After 10 days of culture using 0.05% PNIPAAm, the cell number increased by 11- and 7-fold in case of HepG2 and Huh-7 cells, respectively. Similarly, after 10 days of hepatic spheroids culture on PAG cryogel, the albumin production, urea secretion, and CYP450 activity were significantly higher in case of culture with PNIPAAm. The developed tissue mass on the PAG cryogel in the presence of PNIPAAm possess polarity, which was confirmed using F-actin staining and by presence of intercellular bile canalicular lumen. The developed cryogel matrix supports liver cells proliferation and functionality and therefore can be used for in vitro and in vivo drug testing.
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Affiliation(s)
- Jyoti Kumari
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur , Kanpur, 208016 UP, India
| | - Anjali A Karande
- Department of Biochemistry, Indian Institute of Sciences , Bangalore 560012, India
| | - Ashok Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur , Kanpur, 208016 UP, India
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11
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The Influence of Dopants on the Effectiveness of Alginate Beads in Immobilized Cell Reactors. Appl Biochem Biotechnol 2015; 178:1503-9. [PMID: 26707587 DOI: 10.1007/s12010-015-1963-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/16/2015] [Indexed: 10/22/2022]
Abstract
Zymomonas mobilis immobilized in doped calcium alginate (Ca-alginate) was successfully employed for the production of ethanol in an immobilized cell reactor. Polyethylene oxide and F127 dimethacrylate were evaluated as potential dopants for Ca-alginate beads to decrease lag time and increase initial ethanol yield. The influence of the type and concentration of the dopant on the effectiveness of the microbe immobilized in Ca-alginate beads to produce ethanol was studied, and results were compared to the widely used 2 % Ca-alginate with no dopants, which acted as control. Immobilized cell reactors that were operated using beads doped with 0.25 % polyethylene oxide (PEO) reached an ethanol yield of ∼70 % in 24 h, which was significantly higher than an ethanol yield of 25 % obtained for the control reactor operated using undoped Ca-alginate beads. This study shows that the use of water-soluble dopants can potentially reduce the lag phase and thus improve the initial production yield of immobilized cell reactors, likely due to an increase in porosity and diffusion rate of the doped beads.
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12
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Köllmer M, Appel AA, Somo SI, Brey EM. Long-Term Function of Alginate-Encapsulated Islets. TISSUE ENGINEERING PART B-REVIEWS 2015; 22:34-46. [PMID: 26414084 DOI: 10.1089/ten.teb.2015.0140] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Human trials have demonstrated the feasibility of alginate-encapsulated islet cells for the treatment of type 1 diabetes. Encapsulated islets can be protected from the host's immune system and remain viable and functional following transplantation. However, the long-term success of these therapies requires that alginate microcapsules maintain their immunoprotective capacity and stability in vivo for sustained periods. In part, as a consequence of different encapsulation strategies, islet encapsulation studies have produced inconsistent results in regard to graft functioning time, stability, and overall metabolic benefits. Alginate composition (proportion of M- and G-blocks), alginate purity, the cross-linking ions (calcium or barium), and the presence or absence of additional polymer coating layers influence the success of cell encapsulation. This review summarizes the outcomes of long-term studies of alginate-encapsulated islet transplants in animals and humans and provides a critical discussion of the graft failure mechanisms, including issues with graft biocompatibility, transplantation site, and integrity of the encapsulated islet grafts. Strategies to improve the mechanical stability of alginate capsules and methods for monitoring graft survival and function in vivo are presented.
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Affiliation(s)
- Melanie Köllmer
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois
| | - Alyssa A Appel
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
| | - Sami I Somo
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
| | - Eric M Brey
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
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13
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Ahadian S, Sadeghian RB, Salehi S, Ostrovidov S, Bae H, Ramalingam M, Khademhosseini A. Bioconjugated Hydrogels for Tissue Engineering and Regenerative Medicine. Bioconjug Chem 2015; 26:1984-2001. [DOI: 10.1021/acs.bioconjchem.5b00360] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Samad Ahadian
- WPI-Advanced
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Ramin Banan Sadeghian
- WPI-Advanced
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Sahar Salehi
- WPI-Advanced
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Serge Ostrovidov
- WPI-Advanced
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Hojae Bae
- College
of Animal Bioscience and Technology, Department of Bioindustrial Technologies, Konkuk University, Hwayang-dong,
Kwangjin-gu, Seoul 143-701, Republic of Korea
| | - Murugan Ramalingam
- WPI-Advanced
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Centre
for Stem Cell Research, Institute for Stem Cell Biology and Regenerative Medicine, Christian Medical College Campus, Vellore 632002, India
| | - Ali Khademhosseini
- WPI-Advanced
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- College
of Animal Bioscience and Technology, Department of Bioindustrial Technologies, Konkuk University, Hwayang-dong,
Kwangjin-gu, Seoul 143-701, Republic of Korea
- Department
of Medicine, Center for Biomedical Engineering, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, Massachusetts 02139, United States
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
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14
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Liaudanskaya V, Gasperini L, Maniglio D, Motta A, Migliaresi C. Assessing the Impact of Electrohydrodynamic Jetting on Encapsulated Cell Viability, Proliferation, and Ability to Self-Assemble in Three-Dimensional Structures. Tissue Eng Part C Methods 2015; 21:631-8. [DOI: 10.1089/ten.tec.2014.0228] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Volha Liaudanskaya
- Department of Industrial Engineering, Biotech Research Center, University of Trento, Trento, Italy
- European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy
| | - Luca Gasperini
- Department of Industrial Engineering, Biotech Research Center, University of Trento, Trento, Italy
- European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy
| | - Devid Maniglio
- Department of Industrial Engineering, Biotech Research Center, University of Trento, Trento, Italy
- European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy
| | - Antonella Motta
- Department of Industrial Engineering, Biotech Research Center, University of Trento, Trento, Italy
- European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy
| | - Claudio Migliaresi
- Department of Industrial Engineering, Biotech Research Center, University of Trento, Trento, Italy
- European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy
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15
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Microencapsulated human mesenchymal stem cells decrease liver fibrosis in mice. J Hepatol 2015; 62:634-41. [PMID: 25450712 DOI: 10.1016/j.jhep.2014.10.030] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 01/07/2023]
Abstract
BACKGROUND & AIMS Mesenchymal stem cell (MSC) transplantation was shown to be effective for the treatment of liver fibrosis, but the mechanisms of action are not yet fully understood. We transplanted encapsulated human MSCs in two mouse models of liver fibrosis to determine the mechanisms behind the protective effect. METHODS Human bone marrow-derived MSCs were microencapsulated in novel alginate-polyethylene glycol microspheres. In vitro, we analyzed the effect of MSC-conditioned medium on the activation of hepatic stellate cells and the viability, proliferation, cytokine secretion, and differentiation capacity of encapsulated MSCs. The level of fibrosis induced by bile duct ligation (BDL) or carbon tetrachloride (CCl4) was assessed after intraperitoneal transplantation of encapsulated MSCs, encapsulated human fibroblasts, and empty microspheres. RESULTS MSC-conditioned medium inhibited hepatic stellate cell activation and release of MSC secreted anti-apoptotic (IL-6, IGFBP-2) and anti-inflammatory (IL-1Ra) cytokines. Viability, proliferation, and cytokine secretion of microencapsulated MSCs were similar to those of non-encapsulated MSCs. Within the microspheres, MSCs maintained their capacity to differentiate into adipocytes, chondrocytes, and osteocytes. 23% (5/22) of the MSC clones were able to produce anti-inflammatory IL-1Ra in vitro. Microencapsulated MSCs significantly delayed the development of BDL- and CCl4-induced liver fibrosis. Fibroblasts had an intermediate effect against CCl4-induced fibrosis. Mice transplanted with encapsulated MSCs showed lower mRNA levels of collagen type I, whereas levels of matrix metalloproteinase 9 were significantly higher. Human IL-1Ra was detected in the serum of 36% (4/11) of the mice transplanted with microencapsulated MSCs. CONCLUSIONS MSC-derived soluble molecules are responsible for an anti-fibrotic effect in experimental liver fibrosis.
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16
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Lee BH, Kim MH, Lee JH, Seliktar D, Cho NJ, Tan LP. Modulation of Huh7.5 spheroid formation and functionality using modified PEG-based hydrogels of different stiffness. PLoS One 2015; 10:e0118123. [PMID: 25692976 PMCID: PMC4333219 DOI: 10.1371/journal.pone.0118123] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/05/2015] [Indexed: 12/12/2022] Open
Abstract
Physical cues, such as cell microenvironment stiffness, are known to be important factors in modulating cellular behaviors such as differentiation, viability, and proliferation. Apart from being able to trigger these effects, mechanical stiffness tuning is a very convenient approach that could be implemented readily into smart scaffold designs. In this study, fibrinogen-modified poly(ethylene glycol)-diacrylate (PEG-DA) based hydrogels with tunable mechanical properties were synthesized and applied to control the spheroid formation and liver-like function of encapsulated Huh7.5 cells in an engineered, three-dimensional liver tissue model. By controlling hydrogel stiffness (0.1–6 kPa) as a cue for mechanotransduction representing different stiffness of a normal liver and a diseased cirrhotic liver, spheroids ranging from 50 to 200 μm were formed over a three week time-span. Hydrogels with better compliance (i.e. lower stiffness) promoted formation of larger spheroids. The highest rates of cell proliferation, albumin secretion, and CYP450 expression were all observed for spheroids in less stiff hydrogels like a normal liver in a healthy state. We also identified that the hydrogel modification by incorporation of PEGylated-fibrinogen within the hydrogel matrix enhanced cell survival and functionality possibly owing to more binding of autocrine fibronectin. Taken together, our findings establish guidelines to control the formation of Huh7.5 cell spheroids in modified PEGDA based hydrogels. These spheroids may serve as models for applications such as screening of pharmacological drug candidates.
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Affiliation(s)
- Bae Hoon Lee
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Myung Hee Kim
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jae Ho Lee
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Dror Seliktar
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa, Israel
| | - Nam-Joon Cho
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
- * E-mail: (NJC); (LPT)
| | - Lay Poh Tan
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
- * E-mail: (NJC); (LPT)
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17
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Olabisi RM. Cell microencapsulation with synthetic polymers. J Biomed Mater Res A 2015; 103:846-59. [PMID: 24771675 PMCID: PMC4309473 DOI: 10.1002/jbm.a.35205] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/11/2014] [Accepted: 04/21/2014] [Indexed: 12/18/2022]
Abstract
The encapsulation of cells into polymeric microspheres or microcapsules has permitted the transplantation of cells into human and animal subjects without the need for immunosuppressants. Cell-based therapies use donor cells to provide sustained release of a therapeutic product, such as insulin, and have shown promise in treating a variety of diseases. Immunoisolation of these cells via microencapsulation is a hotly investigated field, and the preferred material of choice has been alginate, a natural polymer derived from seaweed due to its gelling conditions. Although many natural polymers tend to gel in conditions favorable to mammalian cell encapsulation, there remain challenges such as batch to batch variability and residual components from the original source that can lead to an immune response when implanted into a recipient. Synthetic materials have the potential to avoid these issues; however, historically they have required harsh polymerization conditions that are not favorable to mammalian cells. As research into microencapsulation grows, more investigators are exploring methods to microencapsulate cells into synthetic polymers. This review describes a variety of synthetic polymers used to microencapsulate cells.
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Affiliation(s)
- Ronke M Olabisi
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, New Jersey, 08854
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18
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Miao T, Rao KS, Spees JL, Oldinski RA. Osteogenic differentiation of human mesenchymal stem cells through alginate-graft-poly(ethylene glycol) microsphere-mediated intracellular growth factor delivery. J Control Release 2014; 192:57-66. [PMID: 24979209 DOI: 10.1016/j.jconrel.2014.06.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 06/18/2014] [Accepted: 06/19/2014] [Indexed: 01/18/2023]
Abstract
The intracellular delivery of growth factors increases opportunities for controlling cell behavior and maintaining tissue homeostasis. Recently, VEGFA was reported to enhance osteogenic differentiation of mesenchymal stem cells (MSCs) through an intracrine mechanism, suggesting a new strategy to promote bone tissue formation in osteoporotic patients. The goal of this study was to design and fabricate ligand-conjugated alginate-graft-poly(ethylene glycol) microspheres for intracellular delivery and release of VEGFA in primary human MSCs to enhance osteogenic differentiation as a potential therapeutic. Three types of microspheres were synthesized and characterized by scanning electron microscopy, in vitro drug release kinetics, MSC uptake and internalization: alginate alone (Alg), alginate-graft-poly(ethylene glycol) (Alg-g-PEG) and alginate-graft-poly(ethylene glycol)-S-S-arginine-glycine-aspartic acid (Alg-g-RGD). Each of the different microsphere formulations successfully transported bioactive VEGFA into primary human MSCs within 48h of culture, and significantly enhanced osteogenic differentiation compared to control treatments with empty microspheres (intracellular control) or non-encapsulated VEGFA (extracellular control). Adipogenic differentiation was not affected by the presence of VEGFA intracellularly or extracellularly. These results demonstrating the internalization of alginate-based microspheres and intracellular delivery of VEGFA support the efficacy of using this drug delivery and intracrine mechanism to control the fate of human MSCs and enhance osteogenic differentiation.
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Affiliation(s)
- Tianxin Miao
- Bioengineering Program, College of Engineering and Mathematical Sciences, College of Medicine, University of Vermont, Burlington VT 05405, USA.
| | - Krithika S Rao
- Cell and Molecular Biology Graduate Program, College of Medicine, University of Vermont, Burlington, VT 05405, USA.
| | - Jeffrey L Spees
- Cell and Molecular Biology Graduate Program, College of Medicine, University of Vermont, Burlington, VT 05405, USA; Stem Cell Core, University of Vermont, Colchester, VT 05446, USA.
| | - Rachael A Oldinski
- Bioengineering Program, College of Engineering and Mathematical Sciences, College of Medicine, University of Vermont, Burlington VT 05405, USA; Mechanical Engineering Program, College of Engineering and Mathematical Sciences, University of Vermont, Burlington, VT 05405, USA; Department of Orthopaedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, VT 05405, USA.
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19
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Meier RPH, Seebach JD, Morel P, Mahou R, Borot S, Giovannoni L, Parnaud G, Montanari E, Bosco D, Wandrey C, Berney T, Bühler LH, Muller YD. Survival of free and encapsulated human and rat islet xenografts transplanted into the mouse bone marrow. PLoS One 2014; 9:e91268. [PMID: 24625569 PMCID: PMC3953382 DOI: 10.1371/journal.pone.0091268] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 02/10/2014] [Indexed: 01/19/2023] Open
Abstract
Bone marrow was recently proposed as an alternative and potentially immune-privileged site for pancreatic islet transplantation. The aim of the present study was to assess the survival and rejection mechanisms of free and encapsulated xenogeneic islets transplanted into the medullary cavity of the femur, or under the kidney capsule of streptozotocin-induced diabetic C57BL/6 mice. The median survival of free rat islets transplanted into the bone marrow or under the kidney capsule was 9 and 14 days, respectively, whereas that of free human islets was shorter, 7 days (bone marrow) and 10 days (kidney capsule). Infiltrating CD8+ T cells and redistributed CD4+ T cells, and macrophages were detected around the transplanted islets in bone sections. Recipient mouse splenocytes proliferated in response to donor rat stimulator cells. One month after transplantation under both kidney capsule or into bone marrow, encapsulated rat islets had induced a similar degree of fibrotic reaction and still contained insulin positive cells. In conclusion, we successfully established a small animal model for xenogeneic islet transplantation into the bone marrow. The rejection of xenogeneic islets was associated with local and systemic T cell responses and macrophage recruitment. Although there was no evidence for immune-privilege, the bone marrow may represent a feasible site for encapsulated xenogeneic islet transplantation.
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Affiliation(s)
- Raphael P. H. Meier
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Jörg D. Seebach
- Division of Clinical Immunology and Allergology, Department of Internal Medicine, University Hospital and Medical Faculty, Geneva, Switzerland
| | - Philippe Morel
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Redouan Mahou
- Institut d’Ingénierie Biologique et Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sophie Borot
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Laurianne Giovannoni
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Geraldine Parnaud
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Elisa Montanari
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Domenico Bosco
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Christine Wandrey
- Institut d’Ingénierie Biologique et Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Thierry Berney
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Leo H. Bühler
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Yannick D. Muller
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
- Division of Clinical Immunology and Allergology, Department of Internal Medicine, University Hospital and Medical Faculty, Geneva, Switzerland
- * E-mail:
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20
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Mahou R, Kolláriková G, Gonelle-Gispert C, Meier R, Schmitt F, Tran NM, Dufresne M, Altimari I, Lacík I, Bühler L, Juillerat-Jeanneret L, Legallais C, Wandrey C. Combined Electrostatic and Covalent Polymer Networks for Cell Microencapsulation. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/masy.201200099] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Redouan Mahou
- Institut d'Ingénierie Biologique et Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne; station 15; CH-1015 Lausanne; Switzerland
| | | | | | - Raphael Meier
- Surgical Research Unit; University of Geneva; CMU-1; CH-1211 Geneva; Switzerland
| | - Frederic Schmitt
- Institute of Pathology; CHUV-UNIL; CH-1011 Lausanne; Switzerland
| | - Nhu Mai Tran
- CNRS UMR 6600 Université de Technologie de Compiègne; F-60205; Compiègne; France
| | - Murielle Dufresne
- CNRS UMR 6600 Université de Technologie de Compiègne; F-60205; Compiègne; France
| | - Ilaria Altimari
- Institut d'Ingénierie Biologique et Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne; station 15; CH-1015 Lausanne; Switzerland
| | - Igor Lacík
- Polymer Institute of the SAS; Dúbravská cesta 9; 845 41; Bratislava; Slovakia
| | - Léo Bühler
- Surgical Research Unit; University of Geneva; CMU-1; CH-1211 Geneva; Switzerland
| | | | - Cécile Legallais
- CNRS UMR 6600 Université de Technologie de Compiègne; F-60205; Compiègne; France
| | - Christine Wandrey
- Institut d'Ingénierie Biologique et Institut des Sciences et Ingénierie Chimiques; Ecole Polytechnique Fédérale de Lausanne; station 15; CH-1015 Lausanne; Switzerland
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21
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Spasojevic M, Bhujbal S, Paredes G, de Haan BJ, Schouten AJ, de Vos P. Considerations in binding diblock copolymers on hydrophilic alginate beads for providing an immunoprotective membrane. J Biomed Mater Res A 2013; 102:1887-96. [PMID: 23853069 PMCID: PMC4232034 DOI: 10.1002/jbm.a.34863] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/13/2013] [Accepted: 06/28/2013] [Indexed: 01/14/2023]
Abstract
Alginate-based microcapsules are being proposed for treatment of many types of diseases. A major obstacle however in the successes is that these capsules are having large lab-to-lab variations. To make the process more reproducible, we propose to cover the surface of alginate capsules with diblock polymers that can form polymer brushes. In the present study, we describe the stepwise considerations for successful application of diblock copolymer of polyethylene glycol (PEG) and poly-l-lysine (PLL) on the surface of alginate beads. Special procedures had to be designed as alginate beads are hydrophilic and most protocols are designed for hydrophobic biomaterials. The successful attachment of diblock copolymer and the presence of PEG blocks on the surface of the capsules were studied by fluorescence microscopy. Longer time periods, that is, 30–60 min, are required to achieve saturation of the surface. The block lengths influenced the strength of the capsules. Shorter PLL blocks resulted in less stable capsules. Adequate permeability of the capsules was achieved with poly(ethylene glycol)-block-poly(l-lysine hydrochloride) (PEG454-b-PLL100) diblock copolymers. The capsules were a barrier for immunoglobulin G. The PEG454-b-PLL100 capsules have similar mechanical properties as PLL capsules. Minor immune activation of nuclear factor κB in THP-1 monocytes was observed with both PLL and PEG454-b-PLL100 capsules prepared from purified alginate. Our results show that we can successfully apply block copolymers on the surface of hydrophilic alginate beads without interfering with the physicochemical properties.
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Affiliation(s)
- Milica Spasojevic
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, 9747, AG Groningen, the Netherlands; Departments of Pathology and Laboratory Medicine, Section of Medical Biology, Division of Immunoendocrinology, University of Groningen, Hanzeplein 1, 9700, RB Groningen, The Netherlands
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22
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Werner M, Biss K, Jérôme V, Hilbrig F, Freitag R, Zambrano K, Hübner H, Buchholz R, Mahou R, Wandrey C. Use of the mitochondria toxicity assay for quantifying the viable cell density of microencapsulated jurkat cells. Biotechnol Prog 2013; 29:986-93. [PMID: 23636962 DOI: 10.1002/btpr.1734] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/28/2013] [Indexed: 01/19/2023]
Abstract
The mitochondria toxicity assay (MTT assay) is an established method for monitoring cell viability based on mitochondrial activity. Here the MTT assay is proposed for the in situ quantification of the living cell density of microencapsulated Jurkat cells. Three systems were used to encapsulate the cells, namely a membrane consisting of an interpenetrating polyelectrolyte network of sodium cellulose sulphate/poly(diallyldimethylammonium chloride) (NaCS/PDADMAC), a calcium alginate hydrogel covered with poly(L-lysine) (Ca-alg-PLL), and a novel calcium alginate-poly(ethylene glycol) hybrid material (Ca-alg-PEG). MTT results were correlated to data obtained by the trypan blue exclusion assay after release of the cells from the NaCS/PDADMAC and Ca-alg-PLL capsules, while a resazurin-based assay was used for comparison in case of the Ca-alg-PEG material. Analysis by MTT assay allows quick and reliable determination of viable cell densities of encapsulated cells independent of the capsule material. The assay is highly reproducible with inter-assay relative standard deviations below 10%.
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Affiliation(s)
- M Werner
- Chair for Process Biotechnology, University of Bayreuth, Bayreuth, Germany
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23
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Hao Z, Wang L, Xiao K, Zhao Y, Zou M, Zhang Q, Ding Z, Yang F, Qu B. In vivo investigation of ceftiofur-loaded gelatin and PLGA microspheres in beagle dogs. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:903-910. [PMID: 23354736 DOI: 10.1007/s10856-012-4846-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/29/2012] [Indexed: 06/01/2023]
Abstract
Drug delivery systems based on polymer microspheres have received considerable attention. Ceftiofur sodium and ceftiofur hydrochloride is widely used for the treatment of bacterial diseases in animals but the delivery in vivo has not been reported. In this paper, we report the synthesis of microspheres from gelatin and PLGA, two kinds of typical natural and artificial materials, for loading ceftiofur and the in vivo investigation of the pharmacokinetics in beagle dogs. By controlling the synthesis parameters, gelatin and PLGA microspheres with diameter between 5 and 35 microns were obtained. Assay procedures based on high performance liquid chromatography were evaluated and confirmed. The dogs were randomly divided into three groups, i.e., control group, gelatin group, and PLGA group and administrated via intravenous injection. Plasma concentrations of ceftiofur over time were measured and analyzed. Results indicate that the main kinetic parameters do not show significant difference for the gelatin group and control group, but the area under the curve, plasma half-life, apparent volume of distribution, and clearance ratio of PLGA group show significant difference from the gelatin group and the control group. The PLGA microspheres show a low area under the curve but long time release.
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Affiliation(s)
- Zhihui Hao
- Laboratories of Biological Pharmaceutical, College of Chemical and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, China
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