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Cameron A. Best - One of the best experts on this subject based on the ideXlab platform.
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differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long term implantation studies with computational modeling
Acta Biomaterialia, 2019Co-Authors: Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Kevin A Rocco, Hirotsugu Kurobe, Jason M Szafron, Jacob C Zbinden, Shuhei TaraAbstract:Abstract Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-e-caprolactone-co- l -lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neoVessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated physiologic graft function, characterized by 100% patency and luminal matching with adjoining Native Vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neoVessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo. Statement of Significance Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neoVessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation.
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differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long term implantation studies with computational modeling
Acta Biomaterialia, 2019Co-Authors: Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Kevin A Rocco, Hirotsugu Kurobe, Jason M Szafron, Jacob Zbinden, Shuhei TaraAbstract:Abstract Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-e-caprolactone-co-L-lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neoVessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated excellent physiologic graft function, characterized by 100% patency and excellent luminal matching with adjoining Native Vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neoVessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo . Statement of Significance Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neoVessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation.
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In Vivo Applications of Electrospun Tissue-Engineered Vascular Grafts: A Review
Tissue Engineering Part B: Reviews, 2014Co-Authors: Kevin A Rocco, Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Christopher K BreuerAbstract:There is great clinical demand for synthetic vascular grafts with improved long-term efficacy. The ideal vascular conduit is easily implanted, nonthrombogenic, biocompatible, resists aneurysmal dilatation, and ultimately degrades or is assimilated as the patient remodels the graft into tissue resembling Native Vessel. The field of vascular tissue engineering offers an opportunity to design the ideal synthetic graft, and researchers have evaluated a variety of methods and materials for use in graft construction. Electrospinning is one method that has received considerable attention within tissue engineering for constructing so-called tissue scaffolds. Tissue scaffolds are temporary, porous structures which are commonly composed of bioresorbable polymers that promote Native tissue ingrowth and have degradation kinetics compatible with a patient's rate of extracellular matrix production in order to successfully transit from synthetic conduits into neoVessels. In this review, we summarize the history of tissu...
Shuhei Tara - One of the best experts on this subject based on the ideXlab platform.
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differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long term implantation studies with computational modeling
Acta Biomaterialia, 2019Co-Authors: Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Kevin A Rocco, Hirotsugu Kurobe, Jason M Szafron, Jacob C Zbinden, Shuhei TaraAbstract:Abstract Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-e-caprolactone-co- l -lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neoVessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated physiologic graft function, characterized by 100% patency and luminal matching with adjoining Native Vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neoVessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo. Statement of Significance Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neoVessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation.
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differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long term implantation studies with computational modeling
Acta Biomaterialia, 2019Co-Authors: Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Kevin A Rocco, Hirotsugu Kurobe, Jason M Szafron, Jacob Zbinden, Shuhei TaraAbstract:Abstract Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-e-caprolactone-co-L-lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neoVessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated excellent physiologic graft function, characterized by 100% patency and excellent luminal matching with adjoining Native Vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neoVessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo . Statement of Significance Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neoVessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation.
David A Morrow - One of the best experts on this subject based on the ideXlab platform.
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acute limb ischemia and outcomes with vorapaxar in patients with peripheral artery disease results from the trial to assess the effects of vorapaxar in preventing heart attack and stroke in patients with atherosclerosis thrombolysis in myocardial infarction 50 tra2 p timi 50
Circulation, 2016Co-Authors: Marc P Bonaca, Sabina A Murphy, Antonio J Gutierrez, Mark A Creager, Benjamin M Scirica, Jeffrey W Olin, Eugene Braunwald, David A MorrowAbstract:Background Patients with peripheral artery disease (PAD) are at heightened risk of acute limb ischemia (ALI), a morbid event that may result in limb loss. We investigated the causes, sequelae, and predictors of ALI in a contemporary population with symptomatic PAD and whether protease-activated receptor 1 antagonism with vorapaxar reduced ALI overall and by type. Methods and results The Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Patients With Atherosclerosis-Thrombolysis in Myocardial Infarction 50 (TRA2°P-TIMI 50) was a randomized, double-blind, placebo-controlled trial of vorapaxar in stable patients, including 3787 with symptomatic PAD. ALI was a prespecified adjudicated end point using a formal definition. A total of 150 ALI events occurred in 108 patients during follow-up (placebo 3-year rate, 3.9%; 1.3% annualized). For patients with symptomatic PAD, previous peripheral revascularization, smoking, and the ankle-brachial index were predictive of ALI. The majority of ALI events occurred as a result of surgical graft thrombosis (56%), followed by Native Vessel in situ thrombosis (27%). Stent thrombosis and thromboembolism caused ALI in 13% and 5%, respectively. Amputation occurred in 17.6% presenting with ALI. Vorapaxar reduced first ALI events by 41% (hazard ratio, 0.58; 95% confidence interval, 0.39-0.86; P=0.006) and total ALI events by 41% (94 versus 56 events; risk ratio, 0.59; 95% confidence interval, 0.38-0.93; P=0.022). The efficacy of vorapaxar was consistent across types of ALI. Conclusions In selected patients with symptomatic PAD and without atrial fibrillation, ALI occurs at a rate of 1.3%/y, is most frequently caused by acute bypass graft thrombosis or in situ thrombosis of a diseased Vessel, and often results in limb loss. Vorapaxar reduces ALI in patients with symptomatic PAD with consistency across type, including PAD resulting from surgical graft thrombosis and in-situ thrombosis. Clinical trial registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00526474.
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acute limb ischemia and outcomes with vorapaxar in patients with peripheral artery disease results from the trial to assess the effects of vorapaxar in preventing heart attack and stroke in patients with atherosclerosis thrombolysis in myocardial infarction 50 tra2 p timi 50
Circulation, 2016Co-Authors: Marc P Bonaca, Sabina A Murphy, Antonio J Gutierrez, Mark A Creager, Benjamin M Scirica, Jeffrey W Olin, Eugene Braunwald, David A MorrowAbstract:Background— Patients with peripheral artery disease (PAD) are at heightened risk of acute limb ischemia (ALI), a morbid event that may result in limb loss. We investigated the causes, sequelae, and predictors of ALI in a contemporary population with symptomatic PAD and whether protease-activated receptor 1 antagonism with vorapaxar reduced ALI overall and by type. Methods and Results— The Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Patients With Atherosclerosis–Thrombolysis in Myocardial Infarction 50 (TRA2°P-TIMI 50) was a randomized, double-blind, placebo-controlled trial of vorapaxar in stable patients, including 3787 with symptomatic PAD. ALI was a prespecified adjudicated end point using a formal definition. A total of 150 ALI events occurred in 108 patients during follow-up (placebo 3-year rate, 3.9%; 1.3% annualized). For patients with symptomatic PAD, previous peripheral revascularization, smoking, and the ankle-brachial index were predictive of ALI. The majority of ALI events occurred as a result of surgical graft thrombosis (56%), followed by Native Vessel in situ thrombosis (27%). Stent thrombosis and thromboembolism caused ALI in 13% and 5%, respectively. Amputation occurred in 17.6% presenting with ALI. Vorapaxar reduced first ALI events by 41% (hazard ratio, 0.58; 95% confidence interval, 0.39–0.86; P =0.006) and total ALI events by 41% (94 versus 56 events; risk ratio, 0.59; 95% confidence interval, 0.38–0.93; P =0.022). The efficacy of vorapaxar was consistent across types of ALI. Conclusions— In selected patients with symptomatic PAD and without atrial fibrillation, ALI occurs at a rate of 1.3%/y, is most frequently caused by acute bypass graft thrombosis or in situ thrombosis of a diseased Vessel, and often results in limb loss. Vorapaxar reduces ALI in patients with symptomatic PAD with consistency across type, including PAD resulting from surgical graft thrombosis and in-situ thrombosis. Clinical Trial Registration— URL: . Unique identifier: [NCT00526474][1]. # CLINICAL PERSPECTIVE {#article-title-33} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00526474&atom=%2Fcirculationaha%2F133%2F10%2F997.atom
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acute limb ischemia and outcomes with vorapaxar in patients with peripheral artery disease results from tra2 p timi 50
Circulation, 2016Co-Authors: Marc P Bonaca, Sabina A Murphy, Antonio J Gutierrez, Mark A Creager, Benjamin M Scirica, Jeffrey W Olin, Eugene Braunwald, David A MorrowAbstract:Background —Patients with peripheral artery disease (PAD), are at heightened risk of acute limb ischemia (ALI), a morbid event that may result in limb loss. We investigated the causes, sequelae and predictors of ALI in a contemporary population with symptomatic PAD and whether PAR-1 antagonism with vorapaxar reduced ALI overall and by etiology. Methods and Results —TRA2°P-TIMI 50 was a randomized, double-blind, placebo controlled trial of vorapaxar in stable patients including 3,787 with symptomatic PAD. ALI was a prespecified adjudicated endpoint using a formal definition. A total of 150 ALI events occurred in 108 patients during follow-up (placebo 3-yr-rate 3.9%, 1.3% annualized). For patients with symptomatic PAD, prior peripheral revascularization, smoking, and ABI were predictive of ALI. The majority of ALI events occurred due to surgical graft thrombosis (56%), followed by Native Vessel in situ thrombosis (27%). Stent thrombosis and thromboembolism caused ALI in 13% and 5% respectively. Amputation occurred in 17.6% presenting with ALI. Vorapaxar reduced first ALI events by 41% (HR 0.58, 95%CI 0.39-0.86,p=0.006), as well as total ALI events by 41% (94 events vs. 56 events, risk ratio 0.59, 95% CI 0.38-0.93,p=0.022). The efficacy of vorapaxar was consistent across etiology of ALI. Conclusions —In selected patients with symptomatic PAD and without atrial fibrillation, ALI occurs at a rate of 1.3% per year, is most frequently caused by acute bypass graft thrombosis or in situ thrombosis of a diseased Vessel, and often results in limb loss. Vorapaxar reduces ALI in patients with symptomatic PAD with consistency across etiology including surgical graft thrombosis and in-situ thrombosis. Clinical Trial Registration Information —www.clinicaltrials.gov. Identifier: [NCT00526474][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00526474&atom=%2Fcirculationaha%2Fearly%2F2016%2F01%2F29%2FCIRCULATIONAHA.115.019355.atom
Kevin A Rocco - One of the best experts on this subject based on the ideXlab platform.
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differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long term implantation studies with computational modeling
Acta Biomaterialia, 2019Co-Authors: Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Kevin A Rocco, Hirotsugu Kurobe, Jason M Szafron, Jacob C Zbinden, Shuhei TaraAbstract:Abstract Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-e-caprolactone-co- l -lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neoVessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated physiologic graft function, characterized by 100% patency and luminal matching with adjoining Native Vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neoVessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo. Statement of Significance Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neoVessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation.
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differential outcomes of venous and arterial tissue engineered vascular grafts highlight the importance of coupling long term implantation studies with computational modeling
Acta Biomaterialia, 2019Co-Authors: Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Kevin A Rocco, Hirotsugu Kurobe, Jason M Szafron, Jacob Zbinden, Shuhei TaraAbstract:Abstract Electrospinning is commonly used to generate polymeric scaffolds for tissue engineering. Using this approach, we developed a small-diameter tissue engineered vascular graft (TEVG) composed of poly-e-caprolactone-co-L-lactic acid (PCLA) fibers and longitudinally assessed its performance within both the venous and arterial circulations of immunodeficient (SCID/bg) mice. Based on in vitro analysis demonstrating complete loss of graft strength by 12 weeks, we evaluated neoVessel formation in vivo over 6-, 12- and 24-week periods. Mid-term observations indicated excellent physiologic graft function, characterized by 100% patency and excellent luminal matching with adjoining Native Vessel in both the venous and arterial circulations. An active and robust remodeling process was characterized by a confluent endothelial cell monolayer, macrophage infiltrate, and extracellular matrix deposition and remodeling. Long-term follow-up of venous TEVGs at 24 weeks revealed viable neoVessel formation beyond graft degradation when implanted in this high flow, low-pressure environment. Arterial TEVGs experienced catastrophic graft failure due to aneurysmal dilatation and rupture after 14 weeks. Scaffold parameters such as porosity, fiber diameter, and degradation rate informed a previously described computational model of vascular growth and remodeling, and simulations predicted the gross differential performance of the venous and arterial TEVGs over the 24-week time course. Taken together, these results highlight the requirement for in vivo implantation studies to extend past the critical time period of polymer degradation, the importance of differential neotissue deposition relative to the mechanical (pressure) environment, and further support the utility of predictive modeling in the design, use, and evaluation of TEVGs in vivo . Statement of Significance Herein, we apply a biodegradable electrospun vascular graft to the arterial and venous circulations of the mouse and follow recipients beyond the point of polymer degradation. While venous implants formed viable neoVessels, arterial grafts experienced catastrophic rupture due to aneurysmal dilation. We then inform a previously developed computational model of tissue engineered vascular graft growth and remodeling with parameters specific to the electrospun scaffolds utilized in this study. Remarkably, model simulations predict the differential performance of the venous and arterial constructs over 24 weeks. We conclude that computational simulations should inform the rational selection of scaffold parameters to fabricate tissue engineered vascular grafts that must be followed in vivo over time courses extending beyond polymer degradation.
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In Vivo Applications of Electrospun Tissue-Engineered Vascular Grafts: A Review
Tissue Engineering Part B: Reviews, 2014Co-Authors: Kevin A Rocco, Mark W. Maxfield, Cameron A. Best, Ethan W Dean, Christopher K BreuerAbstract:There is great clinical demand for synthetic vascular grafts with improved long-term efficacy. The ideal vascular conduit is easily implanted, nonthrombogenic, biocompatible, resists aneurysmal dilatation, and ultimately degrades or is assimilated as the patient remodels the graft into tissue resembling Native Vessel. The field of vascular tissue engineering offers an opportunity to design the ideal synthetic graft, and researchers have evaluated a variety of methods and materials for use in graft construction. Electrospinning is one method that has received considerable attention within tissue engineering for constructing so-called tissue scaffolds. Tissue scaffolds are temporary, porous structures which are commonly composed of bioresorbable polymers that promote Native tissue ingrowth and have degradation kinetics compatible with a patient's rate of extracellular matrix production in order to successfully transit from synthetic conduits into neoVessels. In this review, we summarize the history of tissu...
Anthony Ratcliffe - One of the best experts on this subject based on the ideXlab platform.
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tissue engineering of vascular grafts
Matrix Biology, 2000Co-Authors: Anthony RatcliffeAbstract:The challenge of tissue engineering blood Vessels with the mechanical properties of Native Vessels, and with the anti-thrombotic properties required is immense. Recent advances, however, indicate that the goal of providing a tissue-engineered vascular graft that will remain patent in vivo for substantial periods of time, is achievable. For instance, collagen gels have been used to fabricate a tissue in vitro that is representative of a Native Vessel: an acellular collagen tubular structure, when implanted as a vascular graft, was able to function, and to become populated with host cells. A completely cellular approach culturing cells into tissue sheets and wrapping these around a mandel was able to form a layered tubular structure with impressive strength. Culture of cells onto a biodegradable scaffold within a dynamic bioreactor, generated a tissue-engineered vascular graft with substantial stiffness and, when lined with endothelial cells, was able to remain patent for up to 4 weeks in vivo. In our experiments, use of a non-degradable polyurethane scaffold and culture with smooth muscle cells generated a construct with mechanical properties similar to Native Vessels. This composite tissue engineered vascular graft with an endothelial layer formed using fluid shear stress to align the endothelial cells, was able to remain patent with an neointima for up to 4 weeks. These results show that tissue engineering of vascular grafts has true potential for application in the clinical situation.