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Gehret, P. M.

Publications and source records attributed to Gehret, P. M..

2 recordsLinked to original sources

A Translational Tissue Engineering Approach to Airway Reconstruction Leveraging Decellularized Meniscus and Cartilage Progenitor Cells

Severe subglottic stenosis develops in over 20,000 infants per year and requires laryngotracheal reconstruction (LTR) to enlarge the airway by implanting autologous cartilage from a rib graft. However, young children often lack sufficiently sized costal cartilage resulting in increased donor site morbidity and operative time, as well as an elevated risk for airway restenosis necessitating revision surgery. To overcome these limitations, we have created a first-of-its-kind scaffold based on porcine meniscal cartilage decellularization (MEND) by selectively digesting the elastin and blood vessels uniquely present in the meniscus to create microchannels that support cellular re-invasion. Here we demonstrated that MEND can be fully recellularized in 3 days with ear-derived cartilage progenitor cells (eCPCs) and reaches structural and functional maturation suitable for implant within 3 weeks of chondrogenic differentiation, a time frame compatible with clinical translation, a first in airway tissue engineering. To further this therapy toward clinical translation, we validated the eCPCs-MEND grafts in a New Zealand white rabbit LTR model. Our results demonstrated airway expansion, graft re-epitheliazation, neocartilage formation, and integration with adjacent native laryngotracheal cartilage, notably at a higher degree than the standard of care of autologous costal cartilage. No instances of adverse events of extrusion, granulation, infection, or calcification were observed in any of the 38 rabbits of our 3 months study. These results demonstrate the feasibility of our translational tissue engineering approach to laryngotracheal reconstruction and could overcome the autograft-associated limitations in pediatric patients and a decrease the risk of invasive revision surgery.

bioengineering↗

Human cartilage progenitor cells from ear, nose, rib, and joint have a robust, stable phenotype for cartilage repair

BackgroundCartilage progenitor cells (CPCs) are a small but highly proliferative cell population that resides within cartilage. Joint cartilage CPCs have a high chondrogenic potential and superior cartilage formation characteristics; however, CPCs from other cartilage sources more accessible for translation such as ear, nose, and rib are broadly unexplored. Our study illuminates the differences between CPCs from these four cartilages, their corresponding tissue chondrocyte (CC), and bone marrow-derived mesenchymal stem cell (MSC). MethodsCPCs subtypes were isolated from pediatric cartilage via fibronectin selection, immunophenotyped by flow cytometry and compared to MSCs. Trilineage differentiation capacity was assessed via histology and qRT-PCR. Next, triiodothyronine was used to hypertrophically challenge each CPC subset and their corresponding chondrocyte population. After 28 days cartilage pellets were assessed via histology, immunohistochemistry, and qRT-PCR. FindingsEach CPC subset possessed a specific immunophenotypic signature with CD56 as a potential common marker. All CPC subsets proliferated 2-fold faster than MSCs and 4-fold faster than CCs. Additionally, CPCs had a substantially reduced propensity for osteogenic differentiation and very limited adipogenic capacity by histology and gene expression. Finally, all CPC subsets resisted the hypertrophic challenge more than the corresponding chondrocyte population marked by less collagen X secretion and downregulation of hypertrophy associated genes. InterpretationCPCs represent a promising cell type for cartilage regeneration. The ease of accessibility of the ear and nose CPCs present opportunities for new translational approaches and reduced clinical timelines. FundingCHOP Research Institute, Frontier Program in Airway Disorders of CHOP, NIH (R21HL159521), NSF-GRFP (DGE-1845298)

bioengineering↗