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Autologous Multipotent Stem Cells for Cell-based Therapies: In vitro and in vivo Differentiation, Maturation and Remodeling of Engineered Functional Cardiovascular Tissues


Schmidt, Dörthe. Autologous Multipotent Stem Cells for Cell-based Therapies: In vitro and in vivo Differentiation, Maturation and Remodeling of Engineered Functional Cardiovascular Tissues. 2016, University of Zurich, Faculty of Medicine.

Abstract

The heterogeneous population of patients suffering from heart valve disease requires strategies addressing the individual conditions, health, age and co-morbidities. Personalized tissue substitutes would be an attractive alternative to current bioprosthetic or mechanical heart valve replacements as these are burdened with several disadvantages such as the lack of growth and remodeling as well as increased risks for degeneration, thromboembolism or immunological reactions. This is addressed by cardiovascular tissue engineering where heart valves are generated from autologous cells in vitro prior to implantation. The special needs of congenital patients are addressed by the pediatric tissue engineering concept. Here cells are harvested prenatally to have the tissue engineered construct ready for implantation at or shortly after birth. In a systematic series of studies we have investigated different human cell sources as to their suitability for cardiovascular tissue engineering thereby suggesting amniotic fluid-derived multipotent stem cells as the ideal cell source. Here, we explored the potential of cryopreservation of human amniotic-fluid-derived multipotent stem cells to expand their use beyond congenital applications to elderly patients. It was shown that cells kept their multipotency after cryopreservation and led to functional heart valves in vitro. This indicates that cryopreserved amniotic fluid-derived cells are a promising life-long available autologous multipotent stem cell source. In this context banking of amniotic fluid-derived cells for future therapies might be an interesting concept. A preclinical in vivo study addressed growth, maturation and remodeling of tissue engineered constructs in a growing sheep model. In order not to compromise in vivo safety and feasibility of the tissue engineering process investigations were first performed with established cell sources. The long-term functionality and growth of engineered cardiovascular tissue substitutes could be demonstrated over a period of 240 weeks. Moreover, it was shown that biological age of cells in the substitutes did not differ from native tissues indicating that remodeling processes take place in vivo. In the last study the clinically relevant minimally invasive implantation of the tissue engineered substitutes was explored in sheep. Autologous stem cell based tissue engineered valves integrated in clinically established nitinol stents could be fabricated, crimped and successfully implanted by a minimally invasive procedure. The in vivo functionality of these stem cell based heart valves was shown. Furthermore, the presence of a functional antithrombotic surface was indicated by the lack of thrombus formation. The presented autologous heart valve tissue engineered concept might be a further step towards the realization of personalized minimally invasively implantable heart valves, addressing the individual needs of the heterogeneous population of affected patients.

Abstract

The heterogeneous population of patients suffering from heart valve disease requires strategies addressing the individual conditions, health, age and co-morbidities. Personalized tissue substitutes would be an attractive alternative to current bioprosthetic or mechanical heart valve replacements as these are burdened with several disadvantages such as the lack of growth and remodeling as well as increased risks for degeneration, thromboembolism or immunological reactions. This is addressed by cardiovascular tissue engineering where heart valves are generated from autologous cells in vitro prior to implantation. The special needs of congenital patients are addressed by the pediatric tissue engineering concept. Here cells are harvested prenatally to have the tissue engineered construct ready for implantation at or shortly after birth. In a systematic series of studies we have investigated different human cell sources as to their suitability for cardiovascular tissue engineering thereby suggesting amniotic fluid-derived multipotent stem cells as the ideal cell source. Here, we explored the potential of cryopreservation of human amniotic-fluid-derived multipotent stem cells to expand their use beyond congenital applications to elderly patients. It was shown that cells kept their multipotency after cryopreservation and led to functional heart valves in vitro. This indicates that cryopreserved amniotic fluid-derived cells are a promising life-long available autologous multipotent stem cell source. In this context banking of amniotic fluid-derived cells for future therapies might be an interesting concept. A preclinical in vivo study addressed growth, maturation and remodeling of tissue engineered constructs in a growing sheep model. In order not to compromise in vivo safety and feasibility of the tissue engineering process investigations were first performed with established cell sources. The long-term functionality and growth of engineered cardiovascular tissue substitutes could be demonstrated over a period of 240 weeks. Moreover, it was shown that biological age of cells in the substitutes did not differ from native tissues indicating that remodeling processes take place in vivo. In the last study the clinically relevant minimally invasive implantation of the tissue engineered substitutes was explored in sheep. Autologous stem cell based tissue engineered valves integrated in clinically established nitinol stents could be fabricated, crimped and successfully implanted by a minimally invasive procedure. The in vivo functionality of these stem cell based heart valves was shown. Furthermore, the presence of a functional antithrombotic surface was indicated by the lack of thrombus formation. The presented autologous heart valve tissue engineered concept might be a further step towards the realization of personalized minimally invasively implantable heart valves, addressing the individual needs of the heterogeneous population of affected patients.

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Additional indexing

Item Type:Habilitation
Communities & Collections:04 Faculty of Medicine > University Hospital Zurich > Clinic and Policlinic for Internal Medicine
Dewey Decimal Classification:610 Medicine & health
Language:English
Date:15 June 2016
Deposited On:09 Jan 2018 14:34
Last Modified:02 Feb 2018 12:34
Number of Pages:71
OA Status:Closed

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