Tissue engineering strategies for repairing skeletal muscle are split into the in vitro or the in vivo approach. The in vitro approach attempts to engineer mature and contractile muscle constructs by culturing cells on a biomaterial substrate until it has evolved into a functional tissue that can be transplanted into patients. The in vivo approach involves transplanting cells, either unaided, or in combination with a biomaterial scaffold, to create a local niche at the site of injury from where the cells could influence muscle regeneration either by integrating into the host tissue or by stimulating the body's own regenerative mechanisms to promote new tissue formation. The type of cells that would be used for muscle tissue engineering are
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Stem cells have become a key player in tissue engineering, both for in vitro generation of bones, and in vivo bone regeneration. Scaffolds used in bone tissue engineering must be rigid and resilient since they function as the main supporting framework of bone graft. But they also must be porous, biocompatible, osteoinductive and osteoconductive so that bone tissue can regenerate within the scaffolds. The scaffolds can be made of natural materials, including biological polymers like collagen and inorganic materials like tri-calcium phosphate, or synthetic materials, such as the polymers PLA, PGA, and PLGA. To avoid the limitations imposed by each material on its own, researchers are now mostly designing composites that combine polymers and inorganic minerals, to let the different nature of materials complement each other, and attain optimal and controllable degradation rate and mechanical properties. Bone is a load-bearing tissue and physical forces play key roles in the development and maintenance of its structure. The application of physiologically relevant stimuli to tissue-engineered bone has revealed mechanical cues can stimulate the expression of an osteogenic phenotype, enhance matrix and mineral deposition, and influence tissue organization to improve the functional outcome of engineered bone grafts. For example, in 3D in vitro systems, scaffolds typically shield cells from the direct effects of compressive forces, so compression is rarely used to enhance osteogenic outcomes in vitro. However, during fracture healing in vivo, compression may work synergistically (and in a time-dependent manner) with other micro-environmental stimuli, to enhance bone formation via an endochondral ossification pathway. Understanding the anatomical structure of native bone and how forces are transmitted to cells has revealed the
Stem cells have become a key player in tissue engineering, both for in vitro generation of bones, and in vivo bone regeneration. Scaffolds used in bone tissue engineering must be rigid and resilient since they function as the main supporting framework of bone graft. But they also must be porous, biocompatible, osteoinductive and osteoconductive so that bone tissue can regenerate within the scaffolds. The scaffolds can be made of natural materials, including biological polymers like collagen and inorganic materials like tri-calcium phosphate, or synthetic materials, such as the polymers PLA, PGA, and PLGA. To avoid the limitations imposed by each material on its own, researchers are now mostly designing composites that combine polymers and inorganic minerals, to let the different nature of materials complement each other, and attain optimal and controllable degradation rate and mechanical properties. Bone is a load-bearing tissue and physical forces play key roles in the development and maintenance of its structure. The application of physiologically relevant stimuli to tissue-engineered bone has revealed mechanical cues can stimulate the expression of an osteogenic phenotype, enhance matrix and mineral deposition, and influence tissue organization to improve the functional outcome of engineered bone grafts. For example, in 3D in vitro systems, scaffolds typically shield cells from the direct effects of compressive forces, so compression is rarely used to enhance osteogenic outcomes in vitro. However, during fracture healing in vivo, compression may work synergistically (and in a time-dependent manner) with other micro-environmental stimuli, to enhance bone formation via an endochondral ossification pathway. Understanding the anatomical structure of native bone and how forces are transmitted to cells has revealed the