Loraine L Y Chiu1,2, Joanna F Weber1,2, Stephen D Waldman1,2. 1. Department of Chemical Engineering, Ryerson University, Toronto, Ontario, Canada. 2. Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
Abstract
OBJECTIVES: Current strategies for external ear reconstruction can lead to donor site morbidity and/or surgical complications. Tissue-engineered auricular tissues may provide readily available reconstructive materials that resemble native auricular tissue, which is composed of a cartilaginous region sandwiched between two perichondrial layers. We previously developed scaffold-free bi-layered auricular tissues, consisting of a perichondrial layer and a cartilaginous layer, by cultivating chondrocytes and perichondrial cells in a continuous flow bioreactor. Here, we aimed to improve construct properties and develop strategies to engineer tri-layered auricular constructs that better mimic native auricular tissue. STUDY DESIGN: Experimental study. METHODS: Different concentrations of insulin-like growth factor (IGF)-1 and insulin were supplemented during bioreactor culture to determine conditions for engineering bi-layered constructs. We also investigated two methods of engineering tri-layered constructs. Method 1 used Ficoll separation to isolate perichondrial cells, followed by the seeding of isolated perichondrial cells onto the opposing side of the bi-layered constructs. Method 2 involved the growth of the bi-layered constructs in osteogenic culture medium. RESULTS: The combination of 10 nM IGF-1 and 100 nM insulin led to increased collagen content in the engineered bi-layered constructs. For developing tri-layered constructs, method 2 yielded thicker constructs with better mechanical and biochemical properties compared to method 1. In addition, the presence of the perichondrial layers protected the engineered constructs from tissue calcification. CONCLUSION: Auricular tissues with a biomimetic microstructure can be created by growing chondrocytes and perichondrial cells in a continuous flow bioreactor, followed by cultivation in osteogenic medium. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E272-E283, 2019.
OBJECTIVES: Current strategies for external ear reconstruction can lead to donor site morbidity and/or surgical complications. Tissue-engineered auricular tissues may provide readily available reconstructive materials that resemble native auricular tissue, which is composed of a cartilaginous region sandwiched between two perichondrial layers. We previously developed scaffold-free bi-layered auricular tissues, consisting of a perichondrial layer and a cartilaginous layer, by cultivating chondrocytes and perichondrial cells in a continuous flow bioreactor. Here, we aimed to improve construct properties and develop strategies to engineer tri-layered auricular constructs that better mimic native auricular tissue. STUDY DESIGN: Experimental study. METHODS: Different concentrations of insulin-like growth factor (IGF)-1 and insulin were supplemented during bioreactor culture to determine conditions for engineering bi-layered constructs. We also investigated two methods of engineering tri-layered constructs. Method 1 used Ficoll separation to isolate perichondrial cells, followed by the seeding of isolated perichondrial cells onto the opposing side of the bi-layered constructs. Method 2 involved the growth of the bi-layered constructs in osteogenic culture medium. RESULTS: The combination of 10 nM IGF-1 and 100 nM insulin led to increased collagen content in the engineered bi-layered constructs. For developing tri-layered constructs, method 2 yielded thicker constructs with better mechanical and biochemical properties compared to method 1. In addition, the presence of the perichondrial layers protected the engineered constructs from tissue calcification. CONCLUSION: Auricular tissues with a biomimetic microstructure can be created by growing chondrocytes and perichondrial cells in a continuous flow bioreactor, followed by cultivation in osteogenic medium. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E272-E283, 2019.
Authors: Nilesh C Bhamare; Kishor R Tardalkar; Jeevitaa Kshersagar; Shashikant R Desai; Tejas B Marsale; Mansingraj S Nimbalkar; Shimpa Sharma; Meghnad G Joshi Journal: Cell Tissue Bank Date: 2021-03-03 Impact factor: 1.522