Regenerative rehabilitation is the combination of regenerative biology with approaches for physical medicine. Examples of regenerative rehabilitation include the incorporation of physical activity to promote engraftment of stem cells into muscle tissue and the in vitro use of mechanical stimuli on cultured cells or tissues, as a means to optimize the efficacy of cell therapeutics and tissue engineering technologies. This collection includes content from npj Regenerative Medicine and showcases the advances in technology and bioscaffolds and our understanding of how mechanical forces regulate gene expression, cell fate and cell function to use mechanical forces for regenerative medicine. This collection was coordinated by Associate Editor Dr. Thomas Rando, Guest Editor Dr. Fabrisia Ambrosio, and Managing Editor Dr. Marie-Elizabeth A. Barabas.
Rehabilitative exercise and spatially patterned nanofibrillar scaffolds enhance vascularization and innervation following volumetric muscle loss
A collagen scaffold designed to mimic skeletal muscle, together with rehabilitative exercise, can help regenerate nerves and blood vessels following traumatic muscle injury. Ngan Huang from Stanford University, California, USA, and colleagues created scaffolding composed of collagen nanofibers aligned in parallel, as natural muscle fibers are. They implanted these specially patterned collagen constructs into the shins of mice that had no tibialis anterior muscles. Mice given the opportunity to exercise formed far more nerve connections in their injured muscles compared to mice without exercise wheels in their cages. Active mice also developed significantly more blood vessels in their injured muscles with the parallel-aligned scaffolds compared to other animals with randomly oriented scaffolds, decellularized scaffolds or no implant at all. The findings highlight the potential of combining exercise and biomimetic scaffolds to treat muscle trauma.
A biomagnetic therapy that stimulates adult stem cells helps promote repair in a sheep model of bone injury. Alicia El Haj from Keele University, UK, and colleagues previously developed a technique for activating specific ion channel receptors on stem cells through the use of targeted magnetic nanoparticles and a small magnetic field, but they had not tried the method on anything larger than a mouse. Here, the scientists tested the technique on sheep with injuries to their leg bones. They designed a magnetic array compatible with a sheep leg which could stimulate the cells for repair. They then tagged bone marrow stem cells with the nanoparticles, implanted the tagged cells at the site of injury, and applied an external magnetic array around the leg. The therapy accelerated repair and enhanced bone growth compared to non-magnetically enhanced stem-cell treatments.