The Experts below are selected from a list of 56190 Experts worldwide ranked by ideXlab platform
Arash Baghayee - One of the best experts on this subject based on the ideXlab platform.
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determining the optimal decellularization and sterilization protocol for preparing a Tissue Scaffold of a human sized liver Tissue
Tissue Engineering Part C-methods, 2013Co-Authors: Abdol-mohammad Kajbafzadeh, Maryam Monajemzadeh, Niloufar Javanfarazmand, Arash BaghayeeAbstract:Attaining a well-qualified whole decellularized organ applicable for an enduring and successful transplantation, decellularization protocols should be organ specific in terms of decellularizing agents and time of Tissue exposure. Since a bioScaffold resulting from a large solid organ should have the potential to preserve its three-dimensional architecture and consistency for at least several months in the site of transplantation, evaluating the mechanical properties of the bioScaffold is mandatory before transplantation. In the current study, we compared five different decellularization protocols and also two main decellularization techniques (perfusion vs. diffusion) to decellularize the sheep liver, which is similar to the human liver in terms of size and anatomy. Moreover, we assessed the retaining of vascular network by dye injection and angiography. We also determined the most proper sterilization method by comparing six different sterilization methods. The mechanical properties of the Scaffolds were...
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Determining the Optimal Decellularization and Sterilization Protocol for Preparing a Tissue Scaffold of a Human-Sized Liver Tissue
Tissue Engineering Part C: Methods, 2013Co-Authors: Abdol-mohammad Kajbafzadeh, Niloufar Javan-farazmand, Maryam Monajemzadeh, Arash BaghayeeAbstract:Attaining a well-qualified whole decellularized organ applicable for an enduring and successful transplantation, decellularization protocols should be organ specific in terms of decellularizing agents and time of Tissue exposure. Since a bioScaffold resulting from a large solid organ should have the potential to preserve its three-dimensional architecture and consistency for at least several months in the site of transplantation, evaluating the mechanical properties of the bioScaffold is mandatory before transplantation. In the current study, we compared five different decellularization protocols and also two main decellularization techniques (perfusion vs. diffusion) to decellularize the sheep liver, which is similar to the human liver in terms of size and anatomy. Moreover, we assessed the retaining of vascular network by dye injection and angiography. We also determined the most proper sterilization method by comparing six different sterilization methods. The mechanical properties of the Scaffolds were assessed by applying tensile strength, suture retention, and compressive strength tests. The perfusion technique showed better results compared to the diffusion technique. The protocol containing ammonium hydroxide and triton X-100 was the most proper decellularization protocol leading to completely decellularized livers along with intact vascular network. Furthermore, we noted that application of streptokinase in washing step facilitates decellularization. Our results also showed that a combination of two sterilization methods is necessary for complete sterilization of a sheep liver and peracetic acid or ethylene oxide+gamma irradiation was associated with the best outcome. Determining the most appropriate decellularization and sterilization method for each organ along with assessing the mechanical properties of the resulting bioScaffold are principal steps before fabricating efficient artificial organs in the foreseeable future.
Wei Sun - One of the best experts on this subject based on the ideXlab platform.
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biopolymer deposition for freeform fabrication of hydrogel Tissue constructs
Materials Science and Engineering: C, 2007Co-Authors: Saif Khalil, Wei SunAbstract:Three-dimensional (3D) Tissue Scaffolds play a vital role as extra-cellular matrices onto which cells can attach, grow, and form new Tissue. Among available biomaterials, hydrogels, such as alginate, fibrin, and chitosan, have promising potential in Tissue engineering applications because of their structural similarities to macromolecular-based human Tissues, their biocompatibility, low toxicity, and availability. The presentation will report our recent research on development of a novel multi-nozzle biopolymer deposition system for freeform fabrication of biopolymer-based Tissue Scaffolds and cell-embedded Tissue constructs. The process of the biopolymer deposition is conducted in a biocompatible environment which allows the construction of Scaffolds with bioactive compounds and living cells. The system configuration and the process for fabrication of bioactive Scaffolds through the biopolymer depositions system under different nozzle system will be described. Results of study on deposition feasibility and 3D structural formability of alginate-based Tissue Scaffolds will be reported. A semi-empirical model, developed based on the Poiseulle's equation for non-Newtonian fluids to predict the deposition flow rate and the deposition geometry, along with comparison of experimental data will be presented. Deposition of cell embedded Tissue Scaffold as well as the cell viability will be introduced. Results of effect of the process parameters on the structural, mechanical and cellular Tissue engineering properties for freeform fabricated 3D alginate Tissue Scaffolds will also be presented.
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computer aided characterization for effective mechanical properties of porous Tissue Scaffolds
Computer-aided Design, 2005Co-Authors: Z. Fang, Binil Starly, Wei SunAbstract:Abstract Performance of various functions of the Tissue structure depends on porous Scaffold microstructures with specific porosity characteristics that influence the behavior of the incorporated or ingrown cells. Understanding the mechanical properties of porous Tissue Scaffold is important for its biological and biomechanical Tissue engineering application. This paper presents a computer aided characterization approach to evaluate the effective mechanical properties of porous Tissue Scaffold. An outline of a computer-aided Tissue engineering approach for design and fabrication of porous Tissue Scaffold, procedure of computer-aided characterization and its interface with design model, development of a computational algorithm for finite element implementation and numerical solution of asymptotic homogenization theory is presented. Application of the algorithm to characterize the effective mechanical properties of porous poly-e-caprolactone Scaffold manufactured by precision extruding freeform deposition will also be presented, along with a parametric study of the process and design parameter to the structural properties of Tissue Scaffold.
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computer aided Tissue engineering overview scope and challenges
Biotechnology and Applied Biochemistry, 2004Co-Authors: Wei Sun, A Darling, Binil Starly, Jae NamAbstract:Advances in computer-aided technology and its application with biology, engineering and information science to Tissue engineering have evolved a new field of computer-aided Tissue engineering (CATE). This emerging field encompasses computer-aided design (CAD), image processing, manufacturing and solid free-form fabrication (SFF) for modelling, designing, simulation and manufacturing of biological Tissue and organ substitutes. The present Review describes some salient advances in this field, particularly in computer-aided Tissue modeling, computer-aided Tissue informatics and computer-aided Tissue Scaffold design and fabrication. Methodologies of development of CATE modelling from high-resolution non-invasive imaging and image-based three-dimensional reconstruction, and various reconstructive techniques for CAD-based Tissue modelling generation will be described. The latest development in SFF to Tissue engineering and a framework of bio-blueprint modelling for three-dimensional cell and organ printing will also be introduced.
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computer aided Tissue engineering application to biomimetic modelling and design of Tissue Scaffolds
Biotechnology and Applied Biochemistry, 2004Co-Authors: Wei Sun, Binil Starly, A Darling, Connie GomezAbstract:Computer-aided Tissue engineering (CATE) enables many novel approaches in modelling, design and fabrication of complex Tissue substitutes with enhanced functionality and improved cell–matrix interactions. Central to CATE is its bio-Tissue informatics model that represents Tissue biological, biomechanical and biochemical information that serves as a central repository to interface design, simulation and Tissue fabrication. The present paper discusses the application of a CATE approach to the biomimetic design of bone Tissue Scaffold. A general CATE-based process for biomimetic modelling, anatomic reconstruction, computer-assisted-design of Tissue Scaffold, quantitative-computed-tomography characterization, finite element analysis and freeform extruding deposition for fabrication of Scaffold is presented.
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computer aided Tissue engineering application to biomimetic modelling and design of Tissue Scaffolds
Biotechnology and Applied Biochemistry, 2004Co-Authors: Wei Sun, Binil Starly, A Darling, Connie GomezAbstract:Computer-aided Tissue engineering (CATE) enables many novel approaches in modelling, design and fabrication of complex Tissue substitutes with enhanced functionality and improved cell–matrix interactions. Central to CATE is its bio-Tissue informatics model that represents Tissue biological, biomechanical and biochemical information that serves as a central repository to interface design, simulation and Tissue fabrication. The present paper discusses the application of a CATE approach to the biomimetic design of bone Tissue Scaffold. A general CATE-based process for biomimetic modelling, anatomic reconstruction, computer-assisted-design of Tissue Scaffold, quantitative-computed-tomography characterization, finite element analysis and freeform extruding deposition for fabrication of Scaffold is presented.
Buddy D Ratner - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a sphere templated polymeric Scaffold as a subcutaneous implant
JAMA Facial Plastic Surgery, 2012Co-Authors: Amit D Bhrany, Colleen Irvin, Kenji Fujitani, Buddy D RatnerAbstract:Objective To evaluate the performance of a sphere-templated poly(2-hydroxyethyl methacrylate) (poly[HEMA]) Tissue Scaffold as a subcutaneous implant by comparing it with widely used high-density porous polyethylene (HDPPE) implant material. Design We implanted sphere-templated porous poly-(HEMA) and HDPPE disks into the dorsal subcutis of C57BL/6 mice for 4 and 9 weeks. Excisional biopsy specimens of the implants and surrounding Tissue were assessed for host inflammatory response, Tissue ingrowth, and neovascularization using trichrome, picrosirius red, and anti–endothelial cell antibody staining. Results The poly(HEMA) and HDPPE implants showed resistance to extrusion and elicited a minimal inflammatory response. Both implants supported cellular and collagen ingrowth, but ingrowth within the HDPPE implant was thicker owing to the larger porous structure (>100 μm) of HDPPE, whereas the poly(HEMA) implant had much thinner collagen fibrils within much smaller (40-μm) pores, suggestive of less scar-type reaction. Neovascularization was supported by both implants. Blood vessels were identified within the fibrous ingrowth of the HDPPE and within individual pores of the poly(HEMA). Conclusions Sphere-templated poly(HEMA) implanted as a subcutaneous Tissue Scaffold stimulates a minimal inflammatory response and supports cellular infiltration, collagen formation, and neovascularization. Because of its tightly controlled porous structure, poly-(HEMA) appears to induce less scar-type ingrowth compared with HDPPE.
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Crosslinking of an oesophagus acellular matrix Tissue Scaffold.
Journal of Tissue Engineering and Regenerative Medicine, 2008Co-Authors: Amit D Bhrany, Casey J. Lien, Benjamin L. Beckstead, Neal D. Futran, Nimish H. Muni, Cecilia M. Giachelli, Buddy D RatnerAbstract:The oesophagus acellular matrix (EAM) Tissue-Scaffold has the potential to serve as the foundation for a Tissue-engineered oesophagus for repair of ablative defects. Similar to all collagen-based biomaterials, the EAM is subject to enzymatic degradation in vivo. The introduction of exogenous crosslinks to collagen molecules via glutaraldehyde (Glu) is the most accepted method of stabilizing collagen biomaterials, but fixation with Glu incurs adverse effects. Genipin (Gp), a naturally occurring crosslinking agent, has shown to be effective at improving the stability of collagen-based biomaterials with less cytotoxicity and reduced in vivo inflammatory responses than Glu. The aim of this study was to show that crosslinking with Gp improves the stability of the EAM while maintaining minimal biological reactivity and preserving EAM regeneration potential in a rat model. EAMs were crosslinked with Gp and Glu. Uncrosslinked EAMs served as controls. Denaturation temperature measurement and burst-pressure measurement after enzymatic degradation assays were used to determine the effectiveness of crosslinking on in vitro stability. Subcutaneous allograft implantation and oesophageal epithelial cell-seeding studies assessed the crosslinking effects on biological reactivity and regeneration potential, respectively. Both Gp and Glu improved EAM stability. After 30 days of implantation, the EAM elicited a minimal inflammatory response and crosslinking did not increase inflammation. Gp-crosslinked EAMs supported epithelial adhesion and proliferation while Glu-crosslinked EAMs did not. Gp improves the stability of the EAM while maintaining minimal biological reactivity and preserving EAM epithelial proliferation capacity, yielding a Tissue Scaffold that may form the basis of a durable and biocompatible Tissue-engineered oesophagus. Copyright © 2008 John Wiley & Sons, Ltd.
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development of an esophagus acellular matrix Tissue Scaffold
Tissue Engineering, 2006Co-Authors: Amit D Bhrany, Benjamin L. Beckstead, Cecilia M. Giachelli, Tess Lang, Gregory D Farwell, Buddy D RatnerAbstract:A cell-extraction protocol yielding an esophagus acellular matrix (EAM) Scaffold for use in Tissue engineering of an esophagus, including hypotonic lysis, multiple detergent cell extraction steps, and nucleic acid digestion, was developed in a rat model. Histological techniques, burst pressure studies, in vitro esophageal epithelial cell seeding, and in vivo implantation were used to assess cell extraction, extracellular matrix (ECM) preservation, and biocompatibility. Microscopy demonstrated that cell extraction protocols using sodium dodecyl sulfate (SDS) (0.5%, wt/vol) as a detergent resulted in cell-free EAM with retained ECM protein collagen, elastin, laminin, and fibronectin. Burst pressure studies indicated a loss of tensile strength in EAMs, but at intraluminal pressures that were unlikely to affect in vivo application. In vitro cell seeding studies exhibited epithelial cell proliferation with stratification similar to native esophagi after 11 days, and subcutaneously implanted EAMs displayed neov...
Teng Gao - One of the best experts on this subject based on the ideXlab platform.
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mesh nanoelectronics seamless integration of electronics with Tissues
Accounts of Chemical Research, 2018Co-Authors: Xiaochuan Dai, Teng Gao, Guosong Hong, Charles M. LieberAbstract:ConspectusNanobioelectronics represents a rapidly developing field with broad-ranging opportunities in fundamental biological sciences, biotechnology, and medicine. Despite this potential, seamless integration of electronics has been difficult due to fundamental mismatches, including size and mechanical properties, between the elements of the electronic and living biological systems.In this Account, we discuss the concept, development, key demonstrations, and future opportunities of mesh nanoelectronics as a general paradigm for seamless integration of electronics within synthetic Tissues and live animals. We first describe the design and realization of hybrid synthetic Tissues that are innervated in three dimensions (3D) with mesh nanoelectronics where the mesh serves as both as a Tissue Scaffold and as a platform of addressable electronic devices for monitoring and manipulating Tissue behavior. Specific examples of Tissue/nanoelectronic mesh hybrids highlighted include 3D neural Tissue, cardiac patches,...
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three dimensional mapping and regulation of action potential propagation in nanoelectronics innervated Tissues
Nature Nanotechnology, 2016Co-Authors: Xiaochua Dai, Teng Gao, Jia Liu, Wei Zhou, Charles M LiebeAbstract:Three-dimensional Tissue-Scaffold-mimicking nanoelectronics are used to map conduction pathways during cardiac Tissue development, record action potential dynamics in disease and pharmacological models, and actively control action potential propagation.
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three dimensional mapping and regulation of action potential propagation in nanoelectronics innervated Tissues
Nature Nanotechnology, 2016Co-Authors: Xiaochuan Dai, Teng Gao, Jia Liu, Wei Zhou, Charles M. LieberAbstract:Real-time mapping and manipulation of electrophysiology in three-dimensional (3D) Tissues could have important impacts on fundamental scientific and clinical studies, yet realization is hampered by a lack of effective methods. Here we introduce Tissue-Scaffold-mimicking 3D nanoelectronic arrays consisting of 64 addressable devices with subcellular dimensions and a submillisecond temporal resolution. Real-time extracellular action potential (AP) recordings reveal quantitative maps of AP propagation in 3D cardiac Tissues, enable in situ tracing of the evolving topology of 3D conducting pathways in developing cardiac Tissues and probe the dynamics of AP conduction characteristics in a transient arrhythmia disease model and subsequent Tissue self-adaptation. We further demonstrate simultaneous multisite stimulation and mapping to actively manipulate the frequency and direction of AP propagation. These results establish new methodologies for 3D spatiotemporal Tissue recording and control, and demonstrate the potential to impact regenerative medicine, pharmacology and electronic therapeutics.
Charles M. Lieber - One of the best experts on this subject based on the ideXlab platform.
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mesh nanoelectronics seamless integration of electronics with Tissues
Accounts of Chemical Research, 2018Co-Authors: Xiaochuan Dai, Teng Gao, Guosong Hong, Charles M. LieberAbstract:ConspectusNanobioelectronics represents a rapidly developing field with broad-ranging opportunities in fundamental biological sciences, biotechnology, and medicine. Despite this potential, seamless integration of electronics has been difficult due to fundamental mismatches, including size and mechanical properties, between the elements of the electronic and living biological systems.In this Account, we discuss the concept, development, key demonstrations, and future opportunities of mesh nanoelectronics as a general paradigm for seamless integration of electronics within synthetic Tissues and live animals. We first describe the design and realization of hybrid synthetic Tissues that are innervated in three dimensions (3D) with mesh nanoelectronics where the mesh serves as both as a Tissue Scaffold and as a platform of addressable electronic devices for monitoring and manipulating Tissue behavior. Specific examples of Tissue/nanoelectronic mesh hybrids highlighted include 3D neural Tissue, cardiac patches,...
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three dimensional mapping and regulation of action potential propagation in nanoelectronics innervated Tissues
Nature Nanotechnology, 2016Co-Authors: Xiaochuan Dai, Teng Gao, Jia Liu, Wei Zhou, Charles M. LieberAbstract:Real-time mapping and manipulation of electrophysiology in three-dimensional (3D) Tissues could have important impacts on fundamental scientific and clinical studies, yet realization is hampered by a lack of effective methods. Here we introduce Tissue-Scaffold-mimicking 3D nanoelectronic arrays consisting of 64 addressable devices with subcellular dimensions and a submillisecond temporal resolution. Real-time extracellular action potential (AP) recordings reveal quantitative maps of AP propagation in 3D cardiac Tissues, enable in situ tracing of the evolving topology of 3D conducting pathways in developing cardiac Tissues and probe the dynamics of AP conduction characteristics in a transient arrhythmia disease model and subsequent Tissue self-adaptation. We further demonstrate simultaneous multisite stimulation and mapping to actively manipulate the frequency and direction of AP propagation. These results establish new methodologies for 3D spatiotemporal Tissue recording and control, and demonstrate the potential to impact regenerative medicine, pharmacology and electronic therapeutics.
