5-Azacytidine-mediated hMSC behavior on electrospun scaffolds for skeletal muscle regeneration.

Incomplete regeneration after trauma or muscular dysfunction is a common problem in muscle replacement therapies. Recent approaches in tissue engineering allow for the replication of skeletal muscle structure and function in vitro and in vivo by molecular therapies and implantable scaffolds which properly address muscle cells toward myotube differentiation and maturation. Here, we investigate the in vitro response of human mesenchymal stem cells (hMSC) on electrospun fibers made of polycaprolactone (PCL) in the presence of 5-azacytidine (5-AZA) to evaluate how fibrous network may influence the therapeutic effect of drug during in vitro myogenesis. Biological studies demonstrate the ability of hMSCs to differentiate in mature myofibers in supplemented (myogenic) and, preferentially, in 5-AZA-enriched culture. PCL electrospun fibers amplify the 5-AZA capability to induce a low proliferation rate in hMSC, thus promoting hMSC differentiation (MTT assay). Qualitative (Azan Mallory stain, immunofluorescence assay, SEM analyses) and quantitative (ELISA test) assays confirm the synergistic contribution of PCL electrospun fibers and 5-AZA on in vitro myotubes formation and maturation. This result is also confirmed by the expression of muscle-specific proteins related to the myogenic mechanisms in the presence of other muscle inductive signals (i.e., oxytocin, Tweak). Hence, we suggest the use of PCL electrospun fibers as interesting preclinical model to explore the effect of drugs and chemotherapeutics administration after damaged muscle resection.