The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform
Antoni P Tomsia - One of the best experts on this subject based on the ideXlab platform.
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Bioactive glass in tissue engineering
Acta Biomaterialia, 2011Co-Authors: Mohamed N. Rahaman, Steven B. Jung, Lynda F. Bonewald, Qiang Fu, Antoni P TomsiaAbstract:This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in Biomaterials Processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed.
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Bioactive glass in tissue engineering
Acta Biomaterialia, 2011Co-Authors: Mohamed N. Rahaman, B. Sonny Bal, Steven B. Jung, Delbert E. Day, Lynda F. Bonewald, Qiang Fu, Antoni P TomsiaAbstract:This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in Biomaterials Processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
David J. Mooney - One of the best experts on this subject based on the ideXlab platform.
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Open pore biodegradable matrices formed with gas foaming
Journal of Biomedical Materials Research, 1998Co-Authors: Leatrese Harris, David J. MooneyAbstract:Engineering tissues utilizing biodegradable polymer matrices is a promising approach to the treatment of a number of diseases. However, Processing techniques utilized to fabricate these matrices typically involve organic solvents and/or high temperatures. Here we describe a process for fabricating matrices without the use of organic solvents and/or elevated temperatures. Disks comprised of polymer [e.g., poly (D,L-lactic-co-glycolic acid)] and NaCl particles were compression molded at room temperature and subsequently allowed to equilibrate with high pressure CO2 gas (800 psi). Creation of a thermodynamic instability led to the nucleation and growth of gas pores in the polymer particles, resulting in the expansion of the polymer particles. The polymer particles fused to form a continuous matrix with entrapped salt particles. The NaCl particles subsequently were leached to yield macropores within the polymer matrix. The overall porosity and level of pore connectivity were regulated by the ratio of polymer/salt particles and the size of salt particles. Both the compressive modulus (159 ± 130 kPa versus 289 ± 25 kPa) and the tensile modulus (334 ± 52 kPa versus 1100 ± 236 kPa) of the matrices formed with this approach were significantly greater than those formed with a standard solvent casting/particulate leaching process. The utility of these matrices was demonstrated by engineering smooth muscle tissue in vitro with them. This novel process, a combination of high pressure gas foaming and particulate leaching techniques, allows one to fabricate matrices with a well controlled porosity and pore structure. This process avoids the potential negatives associated with the use of high temperatures and/or organic solvents in Biomaterials Processing. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 396–402, 1998.
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Open pore biodegradable matrices formed with gas foaming
Journal of Biomedical Materials Research, 1998Co-Authors: L. D. Harris, Bong Seok Kim, David J. MooneyAbstract:Engineering tissues utilizing biodegradable polymer matrices is a promising approach to the treatment of a number of diseases. However, Processing techniques utilized to fabricate these matrices typically involve organic solvents and/or high temperatures. Here we describe a process for fabricating matrices without the use of organic solvents and/or elevated temperatures. Disks comprised of polymer [e.g., poly (D,L-lactic-co-glycolic acid)] and NaCl particles were compression molded at room temperature and subsequently allowed to equilibrate with high pressure CO2 gas (800 psi). Creation of a thermodynamic instability led to the nucleation and growth of gas pores in the polymer particles, resulting in the expansion of the polymer particles. The polymer particles fused to form a continuous matrix with entrapped salt particles. The NaCl particles subsequently were leached to yield macropores within the polymer matrix. The overall porosity and level of pore connectivity were regulated by the ratio of polymer/salt particles and the size of salt particles. Both the compressive modulus (159+/-130 kPa versus 289+/-25 kPa) and the tensile modulus (334+/-52 kPa versus 1100+/-236 kPa) of the matrices formed with this approach were significantly greater than those formed with a standard solvent casting/particulate leaching process. The utility of these matrices was demonstrated by engineering smooth muscle tissue in vitro with them. This novel process, a combination of high pressure gas foaming and particulate leaching techniques, allows one to fabricate matrices with a well controlled porosity and pore structure. This process avoids the potential negatives associated with the use of high temperatures and/or organic solvents in Biomaterials Processing.
Syed A. M. Tofail - One of the best experts on this subject based on the ideXlab platform.
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3.22 Spark Plasma Sintering of Lead-Free Ferroelectric Ceramic Layers
Comprehensive Materials Finishing, 2017Co-Authors: M. Karimi-jafari, K. Kowal, Syed A. M. TofailAbstract:Spark plasma sintering (SPS) has emerged as a highly promising technique for materials sintering and production and can be used in surface coating and finishes as well as bulk material productions. This paper is devoted to study the parameters involved in SPS sintering of lead ferroelectric ceramics. A short general review on sintering is given followed by a history of SPS method. After this SPS of lead-free ferroelectric ceramics such as hydroxyapatite (HAp) and barium titanate have been presented in more details. Finally, potential capabilities of SPS technique in ferroelectric ceramics and Biomaterials Processing have been outlined.
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Spark Plasma Sintering of Lead-Free Ferroelectric Ceramic Layers
Comprehensive Materials Finishing, 2016Co-Authors: M. Karimi-jafari, K. Kowal, E. Haq, Syed A. M. TofailAbstract:Spark plasma sintering (SPS) has emerged as a highly promising technique for materials sintering and production and can be used in surface coating and finishes as well as bulk material productions. This paper is devoted to study the parameters involved in SPS sintering of lead ferroelectric ceramics. A short general review on sintering is given followed by a history of SPS method. After this SPS of lead-free ferroelectric ceramics such as hydroxyapatite (HAp) and barium titanate have been presented in more details. Finally, potential capabilities of SPS technique in ferroelectric ceramics and Biomaterials Processing have been outlined.
Mohamed N. Rahaman - One of the best experts on this subject based on the ideXlab platform.
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Bioactive glass in tissue engineering
Acta Biomaterialia, 2011Co-Authors: Mohamed N. Rahaman, Steven B. Jung, Lynda F. Bonewald, Qiang Fu, Antoni P TomsiaAbstract:This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in Biomaterials Processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed.
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Bioactive glass in tissue engineering
Acta Biomaterialia, 2011Co-Authors: Mohamed N. Rahaman, B. Sonny Bal, Steven B. Jung, Delbert E. Day, Lynda F. Bonewald, Qiang Fu, Antoni P TomsiaAbstract:This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in Biomaterials Processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Scott J. Hollister - One of the best experts on this subject based on the ideXlab platform.
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Selective Laser Sintering Process Optimization for Layered Manufacturing of CAPA® 6501 Polycaprolactone Bone Tissue Engineering Scaffolds
Journal of Manufacturing Science and Engineering-transactions of The Asme, 2005Co-Authors: B Partee, Scott J. HollisterAbstract:Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present tissue engineering methods generally require the use of porous, bioresorbable scaffolds to serve as temporary three-dimensional templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissues such as bone, cartilage, ligament, and tendon. Recent research strongly suggests that the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile Biomaterials Processing and manufacturing methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. it is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to address these requirements. We have investigated SLS as a technique to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this article, we report on our development of optimal SLS Processing parameters for CAPA® 6501 PCL powder using systematic factorial design of experiments. Using the optimal parameters, we manufactured test scaffolds with designed porous channels and achieved dimensional accuracy to within 3%-8% of design specifications and densities approximately 94% relative to full density. Finally, using the optimal SLS process parameters, we demonstrated the successful fabrication of bone tissue engineering scaffolds based on actual minipig and human condyle scaffold designs.
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Selective laser sintering of polycaprolactone bone tissue engineering scaffolds
Nanoscale Materials Science in Biology and Medicine, 2005Co-Authors: B Partee, Scott J. Hollister, Suman DasAbstract:Present tissue engineering practice requires porous, bioresorbable scaffolds to serve as temporary 3D templates to guide cell attachment, differentiation, and proliferation. Recent research suggests that scaffold material and internal architecture significantly influence regenerate tissue structure and function. However, lack of versatile Biomaterials Processing methods have slowed progress towards fully testing these findings. Our research investigates using selective laser sintering (SLS) to fabricate bone tissue engineering scaffolds. Using SLS, we have fabricated polycaprolactone (PCL) and polycaprolactone/tri-calcium phosphate composite scaffolds. We report on scaffold design and fabrication, mechanical property measurements, and structural characterization via optical microscopy and micro-computed tomography.
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Fabrication of Polycaprolactone Bone Tissue Engineering Scaffolds Using Selective Laser Sintering
Manufacturing Engineering and Materials Handling Engineering, 2004Co-Authors: B Partee, Scott J. HollisterAbstract:Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present practice generally requires the use of porous, bioresorbable scaffolds to serve as temporary 3D templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissue such as bone, cartilage, ligament and tendon. Recent research strongly suggests the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile Biomaterials Processing and fabrication methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. It is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to fulfill these needs. Our research aims to investigate the viability of using SLS to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this work, we report our recent progress on porous scaffold design and fabrication, optimal SLS Processing parameter development using systematic factorial design of experiments, and structural characterization via optical microscopy.© 2004 ASME
