Aerobic Exercise and Scaffolds with Hierarchical Porosity Synergistically Promote Functional Recovery Post Volumetric Muscle Loss

Volumetric muscle loss (VML) is a composite loss of skeletal muscle tissue (greater than 20%) that heals with minimal muscle regeneration, substantial fibrosis, and subsequent functional deficits. Standard treatment, involving free functional muscle transfer and physical therapy, cannot restore full muscle function following VML. Tissue engineered scaffolds, 3D structural templates that mimic native extracellular matrix, are promising to enhance functional muscle formation and recovery. Bioprinted 3D scaffolds are engineered using bioinks, created from scaffolding material, cells, and growth factors, to replicate skeletal muscle architecture with precise control over their spatial deposition. METHODS: The present study evaluates a 3D-printed foam-like scaffold for the treatment of VML in a murine model. This colloidal foam-like scaffold was developed to have high porosity to improve tissue ingrowth, in contrast to dense polymeric scaffolds that routinely resulted in very poor tissue ingrowth, and sufficient stiffness to maintain its shape