The Experts below are selected from a list of 10398 Experts worldwide ranked by ideXlab platform
David M. Wootton - One of the best experts on this subject based on the ideXlab platform.
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biocompatibility and biodegradation studies of pcl β tcp bone tissue scaffold fabricated by structural Porogen method
Journal of Materials Science: Materials in Medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural Porogen method
Journal of materials science. Materials in medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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A novel sucrose Porogen‐based solid freeform fabrication system for bone scaffold manufacturing
Rapid Prototyping Journal, 2010Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:Purpose – Musculoskeletal conditions are a major health concern in the USA because of a large aging population and increased occurrence of sport‐related injuries. Bone tissue engineering may offer a less painful alternative to traditional bone grafts with lower risk of infection. The purpose of this paper is to present a novel Porogen‐based fabrication system for tissue engineering scaffolds using sucrose (C12H22O11) as the Porogen building material.Design/methodology/approach – A new solid freeform fabrication system has been developed and tested, which uses pressurized extrusion to print highly biocompatible and water soluble sucrose bone scaffold Porogens (or negtives). Polycaprolactone (PCL) scaffolds are manufactured by injecting molten polymer into the Porogens, and the Porogens are subsequently dissolved with water. The resultant scaffolds demonstrate the defined porous structure designed into the sucrose Porogen manufacturing computer‐aided design model.Findings – To optimize the Porogen manufactu...
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Study of Structured Porogen Method for Bone Scaffold Fabrication
ASME 2008 International Manufacturing Science and Engineering Conference Volume 2, 2008Co-Authors: David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:The increasing demand on bone scaffolds has promoted the development of tissue engineering fabrication technique for manufacturing bone scaffold. In this study, a novel structured Porogen method for bone scaffold fabrication has been explored. This method has demonstrated highly efficient and reproducible fabrication of structured bone scaffolds which mimics the bone structure. By using commercially available Drop on Demand (DDP) system and three dimensional printer (3-DP) system, at first designed structured Porogens can be manufactured, and then bone scaffolds can be fabricated by injecting the biocomposite materials into the Porogens. The mechanical properties of the fabricated scaffolds using DDP system have been characterized. The biocompatibility of our fabricated scaffolds using 3-DP has been examined. With incorporating of bioactive calcium phosphate into the composite materials, the mechanical strength and bioactivity of the scaffolds made by the structured Porogen method can be improved significantly. This structured Porogen method has a potential to be used on various Solid Freeform Fabrication systems which allows each system to use a single ubiquitous building material to fabricate multiple biomaterial scaffolds with sufficient mechanical integrity.Copyright © 2008 by ASME
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Porogen based solid freeform fabrication of polycaprolactone calcium phosphate scaffolds for tissue engineering
Biomaterials, 2006Co-Authors: Mark J Mondrinos, David M. Wootton, Peter I. Lelkes, Robert S Dembzynski, Venkata K C Byrapogu, Jack ZhouAbstract:Drop on demand printing (DDP) is a solid freeform fabrication (SFF) technique capable of generating microscale physical features required for tissue engineering scaffolds. Here, we report results toward the development of a reproducible manufacturing process for tissue engineering scaffolds based on injectable Porogens fabricated by DDP. Thermoplastic Porogens were designed using Pro/Engineer and fabricated with a commercially available DDP machine. Scaffolds composed of either pure polycaprolactone (PCL) or homogeneous composites of PCL and calcium phosphate (CaP, 10% or 20% w/w) were subsequently fabricated by injection molding of molten polymer-ceramic composites, followed by Porogen dissolution with ethanol. Scaffold pore sizes, as small as 200 microm, were attainable using the indirect (Porogen-based) method. Scaffold structure and porosity were analyzed by scanning electron microscopy (SEM) and microcomputed tomography, respectively. We characterized the compressive strength of 90:10 and 80:20 PCL-CaP composite materials (19.5+/-1.4 and 24.8+/-1.3 Mpa, respectively) according to ASTM standards, as well as pure PCL scaffolds (2.77+/-0.26 MPa) fabricated using our process. Human embryonic palatal mesenchymal (HEPM) cells attached and proliferated on all scaffolds, as evidenced by fluorescent nuclear staining with Hoechst 33258 and the Alamar Blue assay, with increased proliferation observed on 80:20 PCL-CaP scaffolds. SEM revealed multilayer assembly of HEPM cells on 80:20 PCL-CaP composite, but not pure PCL, scaffolds. In summary, we have developed an SFF-based injection molding process for the fabrication of PCL and PCL-CaP scaffolds that display in vitro cytocompatibility and suitable mechanical properties for hard tissue repair.
Peter I. Lelkes - One of the best experts on this subject based on the ideXlab platform.
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biocompatibility and biodegradation studies of pcl β tcp bone tissue scaffold fabricated by structural Porogen method
Journal of Materials Science: Materials in Medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural Porogen method
Journal of materials science. Materials in medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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A novel sucrose Porogen‐based solid freeform fabrication system for bone scaffold manufacturing
Rapid Prototyping Journal, 2010Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:Purpose – Musculoskeletal conditions are a major health concern in the USA because of a large aging population and increased occurrence of sport‐related injuries. Bone tissue engineering may offer a less painful alternative to traditional bone grafts with lower risk of infection. The purpose of this paper is to present a novel Porogen‐based fabrication system for tissue engineering scaffolds using sucrose (C12H22O11) as the Porogen building material.Design/methodology/approach – A new solid freeform fabrication system has been developed and tested, which uses pressurized extrusion to print highly biocompatible and water soluble sucrose bone scaffold Porogens (or negtives). Polycaprolactone (PCL) scaffolds are manufactured by injecting molten polymer into the Porogens, and the Porogens are subsequently dissolved with water. The resultant scaffolds demonstrate the defined porous structure designed into the sucrose Porogen manufacturing computer‐aided design model.Findings – To optimize the Porogen manufactu...
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Study of Structured Porogen Method for Bone Scaffold Fabrication
ASME 2008 International Manufacturing Science and Engineering Conference Volume 2, 2008Co-Authors: David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:The increasing demand on bone scaffolds has promoted the development of tissue engineering fabrication technique for manufacturing bone scaffold. In this study, a novel structured Porogen method for bone scaffold fabrication has been explored. This method has demonstrated highly efficient and reproducible fabrication of structured bone scaffolds which mimics the bone structure. By using commercially available Drop on Demand (DDP) system and three dimensional printer (3-DP) system, at first designed structured Porogens can be manufactured, and then bone scaffolds can be fabricated by injecting the biocomposite materials into the Porogens. The mechanical properties of the fabricated scaffolds using DDP system have been characterized. The biocompatibility of our fabricated scaffolds using 3-DP has been examined. With incorporating of bioactive calcium phosphate into the composite materials, the mechanical strength and bioactivity of the scaffolds made by the structured Porogen method can be improved significantly. This structured Porogen method has a potential to be used on various Solid Freeform Fabrication systems which allows each system to use a single ubiquitous building material to fabricate multiple biomaterial scaffolds with sufficient mechanical integrity.Copyright © 2008 by ASME
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Porogen based solid freeform fabrication of polycaprolactone calcium phosphate scaffolds for tissue engineering
Biomaterials, 2006Co-Authors: Mark J Mondrinos, David M. Wootton, Peter I. Lelkes, Robert S Dembzynski, Venkata K C Byrapogu, Jack ZhouAbstract:Drop on demand printing (DDP) is a solid freeform fabrication (SFF) technique capable of generating microscale physical features required for tissue engineering scaffolds. Here, we report results toward the development of a reproducible manufacturing process for tissue engineering scaffolds based on injectable Porogens fabricated by DDP. Thermoplastic Porogens were designed using Pro/Engineer and fabricated with a commercially available DDP machine. Scaffolds composed of either pure polycaprolactone (PCL) or homogeneous composites of PCL and calcium phosphate (CaP, 10% or 20% w/w) were subsequently fabricated by injection molding of molten polymer-ceramic composites, followed by Porogen dissolution with ethanol. Scaffold pore sizes, as small as 200 microm, were attainable using the indirect (Porogen-based) method. Scaffold structure and porosity were analyzed by scanning electron microscopy (SEM) and microcomputed tomography, respectively. We characterized the compressive strength of 90:10 and 80:20 PCL-CaP composite materials (19.5+/-1.4 and 24.8+/-1.3 Mpa, respectively) according to ASTM standards, as well as pure PCL scaffolds (2.77+/-0.26 MPa) fabricated using our process. Human embryonic palatal mesenchymal (HEPM) cells attached and proliferated on all scaffolds, as evidenced by fluorescent nuclear staining with Hoechst 33258 and the Alamar Blue assay, with increased proliferation observed on 80:20 PCL-CaP scaffolds. SEM revealed multilayer assembly of HEPM cells on 80:20 PCL-CaP composite, but not pure PCL, scaffolds. In summary, we have developed an SFF-based injection molding process for the fabrication of PCL and PCL-CaP scaffolds that display in vitro cytocompatibility and suitable mechanical properties for hard tissue repair.
Jack G. Zhou - One of the best experts on this subject based on the ideXlab platform.
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Porogen Templating Processes: An Overview
Journal of Manufacturing Science and Engineering, 2014Co-Authors: Yifeng Hong, Jack G. Zhou, Donggang YaoAbstract:Porous materials with well-defined pore shapes, sizes and distributions are highly desired in many emerging applications, particularly for biomedical materials and devices. However, conventional methods for processing porous materials only demonstrated limited capability in morphological control. One promising solution is the Porogen templating process, where a structured Porogen pattern is created first and subsequently used as a template or mold for generation of the desired porous material. Particularly, with solid freeform fabrication, Porogen templates having complex internal structures can be additively fabricated, and they can then be used as molds for molding of porous materials and devices. This article attempts to offer a constructive overview on the state of the art of Porogen patterning and inverse molding, with the goal of explaining the working mechanisms and providing unbiased accounts of the pros and cons of existing techniques and process variants. The article further intends to provide a fundamental understanding of the constituent elements and corresponding building blocks in Porogen templating processes. An increased understanding of these elements will facilitate the development of more capable new processes.
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Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural Porogen method
Journal of materials science. Materials in medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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biocompatibility and biodegradation studies of pcl β tcp bone tissue scaffold fabricated by structural Porogen method
Journal of Materials Science: Materials in Medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
Qingwei Zhang - One of the best experts on this subject based on the ideXlab platform.
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biocompatibility and biodegradation studies of pcl β tcp bone tissue scaffold fabricated by structural Porogen method
Journal of Materials Science: Materials in Medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural Porogen method
Journal of materials science. Materials in medicine, 2012Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Richard Chiou, Jack G. ZhouAbstract:Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal Porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite Porogens fabricated by 3DP. The resolution of printed plaster Porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the Porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled Porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP Porogen method provide essential capability for bone tissue engineering.
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A novel sucrose Porogen‐based solid freeform fabrication system for bone scaffold manufacturing
Rapid Prototyping Journal, 2010Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:Purpose – Musculoskeletal conditions are a major health concern in the USA because of a large aging population and increased occurrence of sport‐related injuries. Bone tissue engineering may offer a less painful alternative to traditional bone grafts with lower risk of infection. The purpose of this paper is to present a novel Porogen‐based fabrication system for tissue engineering scaffolds using sucrose (C12H22O11) as the Porogen building material.Design/methodology/approach – A new solid freeform fabrication system has been developed and tested, which uses pressurized extrusion to print highly biocompatible and water soluble sucrose bone scaffold Porogens (or negtives). Polycaprolactone (PCL) scaffolds are manufactured by injecting molten polymer into the Porogens, and the Porogens are subsequently dissolved with water. The resultant scaffolds demonstrate the defined porous structure designed into the sucrose Porogen manufacturing computer‐aided design model.Findings – To optimize the Porogen manufactu...
Jack Zhou - One of the best experts on this subject based on the ideXlab platform.
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A novel sucrose Porogen‐based solid freeform fabrication system for bone scaffold manufacturing
Rapid Prototyping Journal, 2010Co-Authors: Qingwei Zhang, David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:Purpose – Musculoskeletal conditions are a major health concern in the USA because of a large aging population and increased occurrence of sport‐related injuries. Bone tissue engineering may offer a less painful alternative to traditional bone grafts with lower risk of infection. The purpose of this paper is to present a novel Porogen‐based fabrication system for tissue engineering scaffolds using sucrose (C12H22O11) as the Porogen building material.Design/methodology/approach – A new solid freeform fabrication system has been developed and tested, which uses pressurized extrusion to print highly biocompatible and water soluble sucrose bone scaffold Porogens (or negtives). Polycaprolactone (PCL) scaffolds are manufactured by injecting molten polymer into the Porogens, and the Porogens are subsequently dissolved with water. The resultant scaffolds demonstrate the defined porous structure designed into the sucrose Porogen manufacturing computer‐aided design model.Findings – To optimize the Porogen manufactu...
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Study of Structured Porogen Method for Bone Scaffold Fabrication
ASME 2008 International Manufacturing Science and Engineering Conference Volume 2, 2008Co-Authors: David M. Wootton, Peter I. Lelkes, Jack ZhouAbstract:The increasing demand on bone scaffolds has promoted the development of tissue engineering fabrication technique for manufacturing bone scaffold. In this study, a novel structured Porogen method for bone scaffold fabrication has been explored. This method has demonstrated highly efficient and reproducible fabrication of structured bone scaffolds which mimics the bone structure. By using commercially available Drop on Demand (DDP) system and three dimensional printer (3-DP) system, at first designed structured Porogens can be manufactured, and then bone scaffolds can be fabricated by injecting the biocomposite materials into the Porogens. The mechanical properties of the fabricated scaffolds using DDP system have been characterized. The biocompatibility of our fabricated scaffolds using 3-DP has been examined. With incorporating of bioactive calcium phosphate into the composite materials, the mechanical strength and bioactivity of the scaffolds made by the structured Porogen method can be improved significantly. This structured Porogen method has a potential to be used on various Solid Freeform Fabrication systems which allows each system to use a single ubiquitous building material to fabricate multiple biomaterial scaffolds with sufficient mechanical integrity.Copyright © 2008 by ASME
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Porogen based solid freeform fabrication of polycaprolactone calcium phosphate scaffolds for tissue engineering
Biomaterials, 2006Co-Authors: Mark J Mondrinos, David M. Wootton, Peter I. Lelkes, Robert S Dembzynski, Venkata K C Byrapogu, Jack ZhouAbstract:Drop on demand printing (DDP) is a solid freeform fabrication (SFF) technique capable of generating microscale physical features required for tissue engineering scaffolds. Here, we report results toward the development of a reproducible manufacturing process for tissue engineering scaffolds based on injectable Porogens fabricated by DDP. Thermoplastic Porogens were designed using Pro/Engineer and fabricated with a commercially available DDP machine. Scaffolds composed of either pure polycaprolactone (PCL) or homogeneous composites of PCL and calcium phosphate (CaP, 10% or 20% w/w) were subsequently fabricated by injection molding of molten polymer-ceramic composites, followed by Porogen dissolution with ethanol. Scaffold pore sizes, as small as 200 microm, were attainable using the indirect (Porogen-based) method. Scaffold structure and porosity were analyzed by scanning electron microscopy (SEM) and microcomputed tomography, respectively. We characterized the compressive strength of 90:10 and 80:20 PCL-CaP composite materials (19.5+/-1.4 and 24.8+/-1.3 Mpa, respectively) according to ASTM standards, as well as pure PCL scaffolds (2.77+/-0.26 MPa) fabricated using our process. Human embryonic palatal mesenchymal (HEPM) cells attached and proliferated on all scaffolds, as evidenced by fluorescent nuclear staining with Hoechst 33258 and the Alamar Blue assay, with increased proliferation observed on 80:20 PCL-CaP scaffolds. SEM revealed multilayer assembly of HEPM cells on 80:20 PCL-CaP composite, but not pure PCL, scaffolds. In summary, we have developed an SFF-based injection molding process for the fabrication of PCL and PCL-CaP scaffolds that display in vitro cytocompatibility and suitable mechanical properties for hard tissue repair.