Improving In Vitro Myogenesis and Force Production in Engineered Skeletal Muscle Tissues

Abstract

The growing deficit in suitable tissues for patients awaiting organ transplants demonstrates the clinical need for engineered tissues as alternative graft sources. In skeletal muscle, volumetric muscle loss is any injury exceeding the normal muscle repair mechanism and resulting in permanent functional impairment. Because available treatments seeking to fill the damaged site with healthy graft tissue are limited by a lack of suitable graft sources, tissue engineering of skeletal muscle has been identified as a promising alternative. To date, however, engineered muscles across the field have generated a fraction of the specific force present in native muscle, and this limitation may present a barrier to clinical applicability. This study addressed this force disparity by promoting in vitro muscle development through the following specific aims: 1) Improving myogenic purity of isolated muscle stem cells with microfluidic inertial separation, 2) Increasing myogenic differentiation in developing cells and engineered muscles with dexamethasone steroid supplementation, and 3) Evaluating engineered tissue structure and function in a non-invasive, label-free manner using multiphoton microscopy. All three experiments demonstrated significant improvements in engineered skeletal muscle force production as compared to previous fabrication methods. Especially as tissue-engineered skeletal muscle moves towards translation as a strategy for repairing volumetric muscle loss, consistently improving in vitro force production of engineered skeletal muscle using methods established in this dissertation is essential for advancing both our tissue engineering model and the tissue engineering and regenerative medicine field as a whole.