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Velutheril Thomas L, Nair PD. An electrospun citric acid modified polyvinyl alcohol scaffold for vascular tissue engineering. J BIOACT COMPAT POL 2019. [DOI: 10.1177/0883911519841390] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The main aim of this study is to fabricate an electrospun citric acid modified polyvinyl alcohol polyester that is biodegradable with non-toxic by-products and can be used for the culture of vascular smooth muscle cells. In this study, we have optimized the conditions for the electrospinning process of this polyester. The fibre morphology was studied by scanning electron microscopy which indicated that the fibre diameter was optimum at a range of 200 to 700 µm at 5% concentration and flow rate of 0.3 mL/h. The membranes were characterized for the change in structural aspects at the molecular level. The results showed development of more crystalline domains on electrospinning. The surface characteristics were also explored. Cell culture studies confirmed that the electrospun scaffold supported the attachment and proliferation of smooth muscle cells, which was evident from the cell proliferation assay. Hence, the electrospun polyester scaffolds are non-toxic and biocompatible with vascular smooth muscle cells, and find promising potential as scaffolds for vascular tissue engineering.
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Affiliation(s)
- Lynda Velutheril Thomas
- Division of Tissue Engineering and Regeneration Technologies, Bio-Medical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Prabha Damodaran Nair
- Division of Tissue Engineering and Regeneration Technologies, Bio-Medical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Thomas D, O'Brien T, Pandit A. Toward Customized Extracellular Niche Engineering: Progress in Cell-Entrapment Technologies. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:1703948. [PMID: 29194781 DOI: 10.1002/adma.201703948] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/12/2017] [Indexed: 06/07/2023]
Abstract
The primary aim in tissue engineering is to repair, replace, and regenerate dysfunctional tissues to restore homeostasis. Cell delivery for repair and regeneration is gaining impetus with our understanding of constructing tissue-like environments. However, the perpetual challenge is to identify innovative materials or re-engineer natural materials to model cell-specific tissue-like 3D modules, which can seamlessly integrate and restore functions of the target organ. To devise an optimal functional microenvironment, it is essential to define how simple is complex enough to trigger tissue regeneration or restore cellular function. Here, the purposeful transition of cell immobilization from a cytoprotection point of view to that of a cell-instructive approach is examined, with advances in the understanding of cell-material interactions in a 3D context, and with a view to further application of the knowledge for the development of newer and complex hierarchical tissue assemblies for better examination of cell behavior and offering customized cell-based therapies for tissue engineering.
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Affiliation(s)
- Dilip Thomas
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland Galway, Galway, Ireland
- Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
- Cardiovascular Institute, Stanford University, Palo Alto, CA, 94305, USA
| | - Timothy O'Brien
- Regenerative Medicine Institute (REMEDI), National University of Ireland Galway, Galway, Ireland
| | - Abhay Pandit
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland Galway, Galway, Ireland
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Ko CL, Wu HY, Lin YS, Yang CH, Chen JC, Chen WC. Modulating the release of proteins from a loaded carrier of alginate/gelatin porous spheres immersed in different solutions. Biomed Mater Eng 2017; 28:515-529. [PMID: 28854489 DOI: 10.3233/bme-171690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND A biodegradable porous particle for the controlled biofactor delivery which assembly of pores in scaffolds can improve the permeation and diffusion of drugs or growth factors. OBJECTIVE Porous-spheres in millimeter scale were prepared by mixing sodium alginate and gelatin interpenetrating networks with cross-linkers; interconnected open pores were fabricated through solvent casting and particulate leaching. METHODS Morphological characteristics, degradation, and bovine serum albumin (BSA) release rates of the porous-spheres immersed in three different solutions, namely, deionized distilled water, simulated body fluid (SBF), and phosphate-buffered saline (PBS), were detected. RESULTS Porous-spheres with a large amount of gelatin exhibited an increase in water absorption rates without affecting scaffold strength and no cytotoxicity was elicited. Highly interconnected pores with a diameter of 100-200 µm were uniformly distributed in scaffolds. The weight loss in PBS was faster than that in other solutions; the highest release rate of BSA in SBF was observed for 2 h. The release rates also exhibited linear patterns from 2 h to 24 h in all of the groups. CONCLUSIONS After 1 d of immersion in solutions, BSA release rates in scaffolds logarithmically decreased for 14 d. The degradation of porous-spheres also showed an inverse pattern.
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Affiliation(s)
- Chia-Ling Ko
- Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University. Taichung 407, Taiwan.,Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Hui-Yu Wu
- Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University. Taichung 407, Taiwan.,Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Yu-Sheng Lin
- Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University. Taichung 407, Taiwan
| | - Chun-Hui Yang
- Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University. Taichung 407, Taiwan
| | - Jian-Chih Chen
- Department of Orthopaedics, Kaohsiung Municipal Siaogang Hospital, Kaohsiung 80708, Taiwan.,Department of Orthopaedics, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Wen-Cheng Chen
- Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University. Taichung 407, Taiwan
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Moustafa T, Girod S, Tortosa F, Li R, Sol JC, Rodriguez F, Bastide R, Lazorthes Y, Sallerin B. Viability and Functionality of Bovine Chromaffin Cells Encapsulated into Alginate-PLL Microcapsules with a Liquefied Inner Core. Cell Transplant 2017; 15:121-33. [PMID: 16719046 DOI: 10.3727/000000006783982106] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Implantation of adrenal medullary bovine chromaffin cells (BCC), which synthesize and secrete a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides, has been proposed for the treatment of intractable cancer pain. Macro- or microencapsulation of such cells within semi-permeable membranes is expected to protect the transplant from the host's immune system. In the present study, we report the viability and functionality of BCC encapsulated into microcapsules of alginate-poly-L-lysine (PLL) with a liquefied inner core. The experiment was carried out during 44 days. Empty microcapsules were characterized in terms of morphology, permeability, and mechanical resistance. At the same time, the viability and functionality of both encapsulated and nonencapsulated BCC were evaluated in vitro. We obtained viable BCC with excellent functionality: immunocytochemical analysis revealed robust survival of chromaffin cells 30 days after isolation and microencapsulation. HPLC assay showed that encapsulated BCC released catecholamines basally during the time course study. Taken together, these results demonstrate that viable BCC can be successfully encapsulated into alginate-PLL microcapsules with a liquefied inner core.
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Affiliation(s)
- T Moustafa
- Laboratoire Douleur et Thérapie Cellulaire, Faculté de médecine Rangueil, 133 route de Narbonne, 31 062 Toulouse Cedex, France
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Llacua A, de Haan BJ, Smink SA, de Vos P. Extracellular matrix components supporting human islet function in alginate-based immunoprotective microcapsules for treatment of diabetes. J Biomed Mater Res A 2016; 104:1788-96. [PMID: 26990360 DOI: 10.1002/jbm.a.35706] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/16/2016] [Accepted: 03/02/2016] [Indexed: 02/06/2023]
Abstract
In the pancreas, extracellular matrix (ECM) components play an import role in providing mechanical and physiological support, and also contribute to the function of islets. These ECM-connections are damaged during islet-isolation from the pancreas and are not fully recovered after encapsulation and transplantation. To promote the functional survival of human pancreatic islets, we tested different ECMs molecules in alginate-encapsulated human islets. These were laminin derived recognition sequences, IKVAV, RGD, LRE, PDSGR, collagen I sequence DGEA (0.01 - 1.0 mM), and collagen IV (50 - 200 µg/mL). Interaction with RGD and PDSGR promoted islet viability and glucose induced insulin secretion (GIIS) when it was applied at concentrations ranging from 0.01 - 1.0 mM (p < 0.05). Also the laminin sequence LRE contributed to enhanced GIIS but only at higher concentrations of 1 mM (p < 0.05). Collagen IV also had beneficial effects but only at 50 µg/ml and no further improvement was observed at higher concentrations. IKVAV and DGEA had no effects on human islets. Synergistic effects were observed by adding Collagen(IV)-RGD, Collagen(IV)-LRE, and Collagen(IV)-PDSGR to encapsulated human islets. Our results demonstrate the potential of specific ECM components in support of functional survival of human encapsulated and free islet grafts. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1788-1796, 2016.
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Affiliation(s)
- Alberto Llacua
- Department of Pathology and Medical Biology, Immunoendocrinology, University of Groningen, Hanzeplein 1, Groningen, RB, 9700, The Netherlands
| | - Bart J de Haan
- Department of Pathology and Medical Biology, Immunoendocrinology, University of Groningen, Hanzeplein 1, Groningen, RB, 9700, The Netherlands
| | - Sandra A Smink
- Department of Pathology and Medical Biology, Immunoendocrinology, University of Groningen, Hanzeplein 1, Groningen, RB, 9700, The Netherlands
| | - Paul de Vos
- Department of Pathology and Medical Biology, Immunoendocrinology, University of Groningen, Hanzeplein 1, Groningen, RB, 9700, The Netherlands
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Singh BK, Sirohi R, Archana D, Jain A, Dutta PK. Porous Chitosan Scaffolds: A Systematic Study for Choice of Crosslinker and Growth Factor Incorporation. INT J POLYM MATER PO 2014. [DOI: 10.1080/00914037.2014.936596] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Wang H, Li Y, Jiang S, Zhang P, Min S, Jiang S. Synthesis, antimicrobial activity, and release of tetracycline hydrochloride loaded poly(vinyl alcohol)/soybean protein isolate/zirconium dioxide nanofibrous membranes. J Appl Polym Sci 2014. [DOI: 10.1002/app.40903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Hualin Wang
- School of Chemical Technology; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
- Anhui Institute of Agro-Products Intensive Processing Technology; Hefei Anhui 230009 People's Republic of China
| | - Yanan Li
- School of Chemical Technology; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Suwei Jiang
- School of Chemical Technology; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Peng Zhang
- School of Chemical Technology; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Sun Min
- School of Chemical Technology; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Shaotong Jiang
- School of Biotechnology and Food Engineering; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
- Anhui Institute of Agro-Products Intensive Processing Technology; Hefei Anhui 230009 People's Republic of China
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Cho SH, Lim SM, Han DK, Yuk SH, Im GI, Lee JH. Time-Dependent Alginate/Polyvinyl Alcohol Hydrogels as Injectable Cell Carriers. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 20:863-76. [DOI: 10.1163/156856209x444312] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Sang Ho Cho
- a Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea; Kwang Dong Pharmaceutical Co. Ltd., 621 Jangdang Dong, Pyongtaek 459-020, South Korea
| | - Sung Mook Lim
- b Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea
| | - Dong Keun Han
- c Biomaterials Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, South Korea
| | - Soon Hong Yuk
- d Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea
| | - Gun Il Im
- e Department of Orthopedics, Dongguk University International Hospital, 814 Sigsa Dong, Goyang 411-373, South Korea
| | - Jin Ho Lee
- f Department of Advanced Materials, Hannam University, 461-6 Jeonmin Dong, Yuseong Gu, Daejeon 305-811, South Korea
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Cho SH, Oh SH, Lee JH. Fabrication and characterization of porous alginate/polyvinyl alcohol hybrid scaffolds for 3D cell culture. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 16:933-47. [PMID: 16128229 DOI: 10.1163/1568562054414658] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Porous alginate/polyvinyl alcohol (PVA) hybrid scaffolds as bioartificial cell scaffolds were fabricated to improve cell compatibility as well as flexibility of the scaffolds. The alginate/PVA hybrid scaffolds with different PVA compositions up to 50 wt% were fabricated by a modified freeze-drying method including the physical cross-linking of PVA and the following chemical cross-linking of alginate. The prepared alginate/PVA hybrid scaffolds were characterized by morphology observations using scanning electron microscopy (SEM), the measurements of porosity and average pore sizes and the measurements of compressive strength and modulus. The scaffolds exhibited highly porous, open-cellular pore structures with almost the same surface and cross-sectional porosities (total porosities about 85%, regardless of PVA composition) and the pore sizes from about 290 microm to about 190 microm with increasing PVA composition. The alginate/PVA hybrid scaffolds were more soft and elastic than the control alginate scaffold without significant changes of mechanical strength. The scaffolds were examined for their in vitro cell compatibility by the culture of chondrocytes (human chondrocyte cell line) in the scaffolds and the following analyses by MTT assay and SEM observation. It was observed that the alginate/PVA scaffolds had better cell adhesion and faster growth than the control alginate scaffold. It seems that 30 wt% addition of PVA to alginate in the fabrication of the hybrid scaffolds is desirable for improving their flexibility and cell compatibility.
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Affiliation(s)
- Sang Ho Cho
- Department of Polymer Science and Engineering, Hannam University, 133 Ojeong Dong, Daedeog Gu, Daejeon 306-791, South Korea
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10
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Yeh SK, Yang J, Chiou NR, Daniel T, Lee LJ. Introducing water as a coblowing agent in the carbon dioxide extrusion foaming process for polystyrene thermal insulation foams. POLYM ENG SCI 2010. [DOI: 10.1002/pen.21624] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Thomas LV, Arun U, Remya S, Nair PD. A biodegradable and biocompatible PVA-citric acid polyester with potential applications as matrix for vascular tissue engineering. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20 Suppl 1:S259-69. [PMID: 18925362 DOI: 10.1007/s10856-008-3599-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Accepted: 09/23/2008] [Indexed: 05/22/2023]
Abstract
Unique elastomeric and biocompatible scaffolds were produced by the polyesterification of poly(vinyl alcohol) (PVA) and citric acid via a simple polycondensation reaction. The physicochemical characterization of the materials was done by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), mechanical and surface property analyses. The materials are hydrophilic and have viscoelastic nature. Biodegradable, non-cytotoxic materials that can be tailored into 3D scaffolds could be prepared in an inexpensive manner. This polyester has potential implications in vascular tissue engineering application as a biodegradable elastomeric scaffold.
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Affiliation(s)
- Lynda V Thomas
- Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram 695012, Kerala, India
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12
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Holle G, Riedel K, von Gregory H, Gazyakan E, Raab N, Germann G. [Vacuum-assisted closure therapy. Current status and basic research]. Unfallchirurg 2008; 110:490-504. [PMID: 17546436 DOI: 10.1007/s00113-007-1267-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The gap between the broad clinical use of vacuum-assisted closure therapy (VT) and knowledge of the physiological mechanisms leading to its effectiveness is great. The value of the technique and its future development are dependent on research into these mechanisms. A meta-analysis evaluating the results of basic research on the effectiveness of VT was carried out based on peer reviewed publications. This is considered in relation to other therapeutic approaches of basic research to wound healing (growth factors etc.). Our study includes a concise description of the scientific background to the mechanisms of cell stimulation using basic work on tissue expansion, bone, vessel and nerve distraction as well as in vitro cell stimulation. Evaluation of the scientific data on all known effects of VT was made based on the results from experimental animal studies, the results of randomized clinical studies, observations on clinical applications and case reports. Assessment of the studies was based on design and significance as well as the appraisal of our own clinical experience. Data involving cellular effects (proliferation, synthesis, wound healing), systemic effects (mediators, systemic inflammatory disease), extracellular effects (perfusion, edema, local wound environment, stabilization, barriers) and complex effects of VT (inflammation, matrix function, blood supply) were examined. Systematic analysis of the data allows scientifically interested surgeons rapid access to the theme, the first, to this extent, extensive overview of the current scientific situation as well as a comprehensive bibliography for all areas involving the theme of mechanical cell stimulation. The authors list major areas for future research and encourage the development of multicenter studies.
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Affiliation(s)
- G Holle
- Klinik für Hand-, Plastische und Rekonstruktive Chirurgie--Schwerbrandverletztenzentrum, Klinik für Plastische und Handchirurgie an der Universität Heidelberg, Ludwig-Guttmann-Strasse 13, 67071 Ludwigshafen.
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Mohan N, Nair PD. Polyvinyl alcohol-poly(caprolactone) Semi IPN scaffold with implication for cartilage tissue engineering. J Biomed Mater Res B Appl Biomater 2008; 84:584-94. [PMID: 17618513 DOI: 10.1002/jbm.b.30906] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Polycaprolactone is an FDA approved aliphatic polyester that is widely used as a scaffold for tissue engineering. It is hydrophobic and doesn't have any reactive functional groups on the polymer for further modification. Blending with other hydrophilic polymers like polyvinyl alcohol helps to generate a hybrid polymer with better properties. In this study we have been able to fabricate a novel porous 3D scaffold of Semi-IPN Poly (caprolactone)-Poly (vinyl alcohol). The Semi IPN is phase mixed and has synergistic properties of its constituent polymers. The hybrid scaffold is nontoxic and highly hydrophilic with greater percentage of swelling and is also amenable for further modification with bioactive peptides. Although porous with an open interconnected porous structure, the scaffold has adequate mechanical strength to withstand the load imparted by the cells during in vitro culture. Porcine chondrocytes seeded within the unmodified scaffolds secrete extra cellular matrix components revealing that the hybrid scaffold has immense potential for tissue engineering applications.
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Affiliation(s)
- Neethu Mohan
- Laboratory for Polymer Analysis, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695012, India.
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Kuan WL, Barker RA. New therapeutic approaches to Parkinson's disease including neural transplants. Neurorehabil Neural Repair 2005; 19:155-81. [PMID: 16093408 DOI: 10.1177/1545968305277219] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder of the brain and typically presents with a disorder of movement. The core pathological event underlying the condition is the loss of the dopaminergic nigrostriatal pathway with the formation of alpha-synuclein positive Lewy bodies. As a result, drugs that target the degenerating dopaminergic network within the brain work well at least in the early stages of the disease. Unfortunately, with time these therapies fail and produce their own unique side-effect profile, and this, coupled with the more diffuse pathological and clinical findings in advancing disease, has led to a search for more effective therapies. In this review, the authors will briefly discuss the emerging new drug therapies in PD before concentrating on a more detailed discussion on the state of cell therapies to cure PD.
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Affiliation(s)
- W-L Kuan
- Cambridge Centre for Brain Repair, Cambridge University, UK
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Schwenter F, Bouche N, Pralong WF, Aebischer P. In vivo calcium deposition on polyvinyl alcohol matrix used in hollow fiber cell macroencapsulation devices. Biomaterials 2004; 25:3861-8. [PMID: 15020162 DOI: 10.1016/j.biomaterials.2003.10.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2003] [Accepted: 10/08/2003] [Indexed: 11/19/2022]
Abstract
The encapsulation of genetically modified cells represents a promising approach for the delivery of therapeutic proteins. The functionality of the device is dependent on the characteristics of the biomaterials, the procedures used in its confection and the adaptability of the encapsulated cells in the host. We report conditions leading to the development of calcifications on the polyvinyl alcohol (PVA) matrix introduced in hollow fiber devices for the encapsulation of primary human fibroblasts implanted in mice. The manufacturing procedures, batches of PVA matrix and cell lineages were assessed for their respective role in the development of the phenomenon. The results showed that the calcification is totally prevented by substituting phosphate-buffer saline with ultra-pure sterile water in the rinsing procedure of the matrix. Moreover, a positive correlation was found, when comparing two fibroblast cell lineages, between the level of lactate dehydrogenase (LDH) activity measured in the cells and the degree of calcium deposition. Higher LDH activity may decrease calcium depositions because it generates in the device a more acidic microenvironment inhibiting calcium precipitation. The present study defines optimized conditions for the encapsulation of primary human fibroblasts in order to avoid potentially detrimental calcifications and to allow long-term survival of encapsulated cells.
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Affiliation(s)
- F Schwenter
- Division of Surgical Research and Gene Therapy Center, CHUV, Lausanne University Medical School, Lausanne, Switzerland
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Li AA, MacDonald NC, Chang PL. Effect of growth factors and extracellular matrix materials on the proliferation and differentiation of microencapsulated myoblasts. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2004; 14:533-49. [PMID: 12901436 DOI: 10.1163/15685620360674236] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An alternative approach to gene therapy via non-autologous somatic gene therapy is to implant genetically-engineered cells protected from immune rejection with microcapsules to deliver a therapeutic gene product. This delivery system may be optimized by using myoblast cell lines which can undergo terminal differentiation into myotubes, thus removing the potential problems of tumorigenesis and space restriction. However, once encapsulated, myoblasts do not proliferate or differentiate well. We now report the use of extracellular matrix components and growth factors to improve these properties. Addition of matrix material collagen, merosin or laminin all stimulated myoblast proliferation, particularly when merosin and laminin were combined; however, none, except collagen, stimulated differentiation. Inclusion of basic fibroblast growth factor (bFGF) within the microcapsules in the presence of collagen stimulated proliferation of C2C12 myoblasts, as well as differentiation into myotubes. Inclusion of insulin growth factor (IGF-II) in the microcapsules had no effect on proliferation but accelerated myoblasts differentiation. When the above matrix material and growth factors were provided in combination, the use of merosin and laminin together with bFGF and IGF-II stimulated myoblast proliferation but had no effect on differentiation. In contrast, the cocktail containing bFGF, IGF-II and collagen induced increased myoblasts proliferation and subsequent differentiation. Hence, the combination of bFGF, IGF-II and collagen appears optimal in improving proliferation and differentiation in encapsulated myoblasts.
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Affiliation(s)
- Anna Aihua Li
- Department of Pediatrics, Health Sciences Centre, Room 3N18, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8S 4J9, Canada
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Sreenivasan K. Enhanced drug uptake and retention by surface phosporylated polyvinyl alcohol. J Appl Polym Sci 2004. [DOI: 10.1002/app.20885] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Byrne ME, Oral E, Zachary Hilt J, Peppas NA. Networks for recognition of biomolecules: molecular imprinting and micropatterning poly(ethylene glycol)- Containing films. POLYM ADVAN TECHNOL 2003. [DOI: 10.1002/pat.272] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Whitaker MJ, Quirk RA, Howdle SM, Shakesheff KM. Growth factor release from tissue engineering scaffolds. J Pharm Pharmacol 2001; 53:1427-37. [PMID: 11732745 DOI: 10.1211/0022357011777963] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Synthetic scaffold materials are used in tissue engineering for a variety of applications, including physical supports for the creation of functional tissues, protective gels to aid in wound healing and to encapsulate cells for localized hormone-delivery therapies. In order to encourage successful tissue growth, these scaffold materials must incorporate vital growth factors that are released to control their development. A major challenge lies in the requirement for these growth factor delivery mechanisms to mimic the in-vivo release profiles of factors produced during natural tissue morphogenesis or repair. This review highlights some of the major strategies for creating scaffold constructs reported thus far, along with the approaches taken to incorporate growth factors within the materials and the benefits of combining tissue engineering and drug delivery expertise.
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Affiliation(s)
- M J Whitaker
- School of Pharmaceutical Sciences, The University of Nottingham, UK
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Li RH, Williams S, Burkstrand M, Roos E. Encapsulation matrices for neurotrophic factor-secreting myoblast cells. TISSUE ENGINEERING 2000; 6:151-63. [PMID: 10941210 DOI: 10.1089/107632700320775] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Encapsulated-cell therapy is an emerging technology that entails implantation of cell-containing devices that secrete therapeutic factors. One potential application of this technology is the delivery of neurotrophic factors to treat neurodegenerative disease. These devices typically use an internal matrix to serve as a cell scaffold. This study compares collagen-coated polyethylene terephthalate (PET) yarn scaffold versus collagen as a matrix for engineered C2C12 myoblasts. C2C12 cells transfected to secrete ciliary neurotrophic factor (CNTF) were immobilized in matrices and encapsulated into hollow fiber membrane devices. Encapsulated cells were monitored in vitro for viability, morphology, and factor secretion. Two independent methods (histology assessment and metabolic assay) were used to estimate viable cell density; a high correlation between the methods was found. After 4 weeks, encapsulated devices with PET scaffold had an almost nine-fold greater number of viable cells compared to collagen. PET matrix devices contained a thick annulus of compact, highly oriented cells. Collagen matrix devices contained sparse viable cells in a thin rim. Secretion assays showed cells in PET matrix released approximately four-fold the amount of CNTF versus cells in collagen (averaging 542 and 129 ng/day per device for PET and collagen matrix, respectively). The choice of encapsulation matrix was found to have a profound effect on cell morphology, level of secreted factor, and viability of encapsulated C2C12 cells.
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Affiliation(s)
- R H Li
- Genetics Institute, Andover, Massachusetts 01810, USA.
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Li RH, Williams S, White M, Rein D. Dose control with cell lines used for encapsulated cell therapy. TISSUE ENGINEERING 1999; 5:453-66. [PMID: 10586101 DOI: 10.1089/ten.1999.5.453] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cell therapy-use of cells to deliver active factors-is an emerging technique in treatment of neurodegenerative disease. Successful devices maintain cell viability and functionality over extended implant periods. Use of dividing cell lines to deliver therapeutic factors has been studied extensively. One emerging issue is the tendency of cells to continue proliferation within the intracapsular environment-potentially outstripping nutrient supply. This work presents a method of controlling proliferation and delivering therapeutic molecules within a dose range. The method entails encapsulation into a hollow fiber device of discrete numbers of cell-containing microcarriers. Proliferation control is attained by embedding cell-containing microcarriers in nonmitogenic hydrogels. PC-12 cells secreting L-dopa and dopamine was the model cell line tested. Feasibility of the method in controlling growth of normally rapidly dividing cells in the intracapsular environment was demonstrated in vitro and in vivo. Control nonmicrocarrier PC-12 cell devices had approximately fourfold greater expansion in cell number compared to experimental microcarrier-containing devices over 4 weeks in vitro and in vivo after implant into rat striatum. Ability to control dose released over a several-fold range was demonstrated with encapsulated PC-12 cells delivering neurotransmitters and C2C12 mouse myoblast cells delivering neurotrophic factors (CNTF).
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Affiliation(s)
- R H Li
- Genetics Institute, One Burtt Rd, Andover, MA 01810, USA.
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