Figure 1.

Advances in skeletal muscle tissue engineering—from classic to functional approaches. Until recently, the classic tissue engineering approach was the combination of the following components: biomaterials, cells, and growth factors. In recent years, this classic triad was combined with novel methodologies allowing for more biomimetic approaches. Advances in cross-linking chemistry made it possible to link growth factors to the biomaterial or to provide growth factor binding sites. In addition, guidance cues like patterning or alignment of the biomaterial, as well as the mechanical properties, have been demonstrated to significantly influence cell behavior such as adhesion, migration, and maturation. Likewise, the number of cell types that can potentially be used has increased ranging from cell lines and primary cells to muscle stem cells and cells with mesenchymal stem cells characteristics. One of the major advances in the past has been the incorporation of dynamic culture systems into existing SMTE approaches to improve tissue maturation. In this respect, the most commonly used techniques are electrical or mechanical stimulation via sophisticated bioreactor systems. These bioreactors allow controlled provision of different mechanical or electrical stimuli to drive both early myogenesis and functional maturation. GF, growth factor; 2D, 2-dimensional; 3D, 3-dimensional; SCs, stem cells; IGF, insulin growth factor; FGF, fibroblast growth factor; PDGF, platelet derived growth factor; VEGF, vascular endothelial growth factor.