開發水凝膠以支持肌肉細胞片並誘導神經肌肉接合點的形成

Muscle owns self-regeneration ability. Extensive loss of mass, also known as volumetric muscle loss (VML), is the traumatic or surgical loss of skeletal muscle beyond the inherent regenerative capacity of the body, generally leading to severe functional deficit and also eventually causing atrophy. Transplantation of health muscle tissue can treat VML, but it may make donor site morbidity. Therefore, tissue engineering is developed to provide an alternative clinical option. Cell sheet is a potential technology to obtain engineered muscle because both cell-cell interaction and surrounding ECM molecules can be preserved. In addition, using a bioreactor can provide physical stimulations to promote myogenetic differentiation and myotube alignment. Although myoblasts cultured on thermosensitive materials can be detached as a cell sheet, how to maintain the size of cell sheet without shrinkage is a challenge. In addition, innervation is another issue because skeletal muscle functions upon nervous input. Therefore, we will develop a hydrogel for harvesting muscle cell sheet in this project. Surface modification of hydrogel can firmly adhere cell sheet and avoid shrinkage. Its flexibility also allows myotubes to contract without restriction. This hydrogel will encapsulate neurotropic factors. Because neurotrophic factors will locally release from hydrogel in a gradient distribution, motor axons will be attracted to the muscle cell sheet and neuromuscular junctions (NMJ) may thus form to transmit neural signals. Finally, muscle cell sheet-loading hydrogel will be implanted to an animal model with VML. The recovery of muscle force and the increase of muscle mass will be examined, so we can evaluate the promotion effects of these implants on reinnervation and muscle tissue regeneration, respectively. This study will provide a comprehensive solution to treat severemuscle injury.