Saurav Ranjan Mohapatra1, Elena Rama2, Christoph Melcher3, Tobias Call1, Miriam Aischa Al Enezy-Ulbrich4, Andrij Pich4, Christian Apel1, Fabian Kiessling2, Stefan Jockenhoevel5. 1. Department of Biohybrid and Medical Textiles (BioTex), Center for Biohybrid Medical Systems (CBMS), Institute for Applied Medical Engineering, RWTH Aachen University, Forckenbeckstr. 55, 52074, Aachen, Germany. 2. Institute for Experimental Molecular Imaging, RWTH Aachen University, Forckenbeckstr. 55, 52074, Aachen, Germany. 3. Institute for Textile Technology, RWTH Aachen University, Otto-Blumenthal-Str. 1, 52074, Aachen, Germany. 4. DWI-Leibniz Institute for Interactive Materials, RWTH Aachen University, Forckenbeckstr. 50, 52074, Aachen, Germany. 5. Department of Biohybrid and Medical Textiles (BioTex), Center for Biohybrid Medical Systems (CBMS), Institute for Applied Medical Engineering, RWTH Aachen University, Forckenbeckstr. 55, 52074, Aachen, Germany. jockenhoevel@ame.rwth-aachen.de.
Abstract
BACKGROUND: The production of tissue-engineered vascular graft (TEVG) usually involves a prolonged bioreactor cultivation period of up to several weeks to achieve maturation of extracellular matrix and sufficient mechanical strength. Therefore, we aimed to substantially shorten this conditioning time by combining a TEVG textile scaffold with a recently developed copolymer reinforced fibrin gel as a cell carrier. We further implemented our grafts with magnetic resonance imaging (MRI) contrast agents to allow the in-vitro monitoring of the TEVG's remodeling process. METHODS: Biodegradable polylactic-co-glycolic acid (PLGA) was electrospun onto a non-degradable polyvinylidene fluoride scaffold and molded along with copolymer-reinforced fibrin hydrogel and human arterial cells. Mechanical tests on the TEVGs were performed both instantly after molding and 4 days of bioreactor conditioning. The non-invasive in vitro monitoring of the PLGA degradation and the novel imaging of fluorinated thermoplastic polyurethane (19F-TPU) were performed using 7T MRI. RESULTS: After 4 days of close loop bioreactor conditioning, 617 ± 85 mmHg of burst pressure was achieved, and advanced maturation of extracellular matrix (ECM) was observed by immunohistology, especially in regards to collagen and smooth muscle actin. The suture retention strength (2.24 ± 0.3 N) and axial tensile strength (2.45 ± 0.58 MPa) of the TEVGs achieved higher values than the native arteries used as control. The contrast agents labeling of the TEVGs allowed the monitorability of the PLGA degradation and enabled the visibility of the non-degradable textile component. CONCLUSION: Here, we present a concept for a novel textile-reinforced TEVG, which is successfully produced in 4 days of bioreactor conditioning, characterized by increased ECM maturation and sufficient mechanical strength. Additionally, the combination of our approach with non-invasive imaging provides further insights into TEVG's clinical application.
BACKGROUND: The production of tissue-engineered vascular graft (TEVG) usually involves a prolonged bioreactor cultivation period of up to several weeks to achieve maturation of extracellular matrix and sufficient mechanical strength. Therefore, we aimed to substantially shorten this conditioning time by combining a TEVG textile scaffold with a recently developed copolymer reinforced fibrin gel as a cell carrier. We further implemented our grafts with magnetic resonance imaging (MRI) contrast agents to allow the in-vitro monitoring of the TEVG's remodeling process. METHODS: Biodegradable polylactic-co-glycolic acid (PLGA) was electrospun onto a non-degradable polyvinylidene fluoride scaffold and molded along with copolymer-reinforced fibrin hydrogel and human arterial cells. Mechanical tests on the TEVGs were performed both instantly after molding and 4 days of bioreactor conditioning. The non-invasive in vitro monitoring of the PLGA degradation and the novel imaging of fluorinated thermoplastic polyurethane (19F-TPU) were performed using 7T MRI. RESULTS: After 4 days of close loop bioreactor conditioning, 617 ± 85 mmHg of burst pressure was achieved, and advanced maturation of extracellular matrix (ECM) was observed by immunohistology, especially in regards to collagen and smooth muscle actin. The suture retention strength (2.24 ± 0.3 N) and axial tensile strength (2.45 ± 0.58 MPa) of the TEVGs achieved higher values than the native arteries used as control. The contrast agents labeling of the TEVGs allowed the monitorability of the PLGA degradation and enabled the visibility of the non-degradable textile component. CONCLUSION: Here, we present a concept for a novel textile-reinforced TEVG, which is successfully produced in 4 days of bioreactor conditioning, characterized by increased ECM maturation and sufficient mechanical strength. Additionally, the combination of our approach with non-invasive imaging provides further insights into TEVG's clinical application.
Authors: Sandip Sarkar; Thomas Schmitz-Rixen; George Hamilton; Alexander M Seifalian Journal: Med Biol Eng Comput Date: 2007-03-06 Impact factor: 2.602
Authors: Liqiong Gui; Akihito Muto; Stephen A Chan; Christopher K Breuer; Laura E Niklason Journal: Tissue Eng Part A Date: 2009-09 Impact factor: 3.845