Cartilage Tissue Engineering For Rhinoplasty

Abstract

Nasal surgery (rhinoplasty) has evolved considerably since its origins in Egypt around 1600BCE, yet modern reconstruction still relies on grafts harvested from autologous rib cartilage. Rib cartilage is an excellent graft material, but chest donor site morbidity can be a significant problem. The aim of this thesis was to create a patient specific cartilage surgical product using autologous stem cells that would provide surgeons with an effective alternative to rib cartilage. Adipose-derived stem cells (ADSCs) and cartilage-derived stem/precursor cells (CSPCs) were used in this thesis as they can be harvested through minimally invasive procedures and their chondrogenic potential already widely established. Using a novel tissue clearing protocol for whole mount imaging, primary experiments confirmed the ability of both cell types to self-organize and generate cartilage-like extracellular matrix (ECM) in 3D spheroids. Three different methods of engineering cartilage in 3D were investigated. Firstly, a clinically approved collagen matrix was used as a scaffold and seeded with cells. Immunocytochemistry and histological staining demonstrated cartilage like ECM on the scaffold surface in preference to deeper regions. The collagen matrix proved too be tight and constrictive on cell expansion. Secondly, a 3D bioprinter was used to print cells mixed with cellulose/alginate “bioink” hydrogels. This bioink failed to demonstrate cartilage like ECM in static culture and in a chick embryo chorioallantoic membrane (CAM) model. Lastly, a cell laden fibrin hydrogel was “sandwiched” between 2 layers of polycaprolactone (PCL) sheets to provide mechanical support and grafted onto CAM. Histological analysis of cell laden fibrin confirmed regions of chondrogenesis by positive staining of collagen and glycosaminoglycans. In conclusion, the results provide further understanding of how these cells respond to different 3D environments and the effect on chondrogenesis. Combining 3D bioprinting with a sandwich design may be an effective future approach to product development

    Similar works