Schwann Cells Do Not Promote Myogenic Differentiation in the EPI Loop Model.

In skeletal muscle tissue engineering, innervation and vascularization play an essential role in the establishment of functional skeletal muscle. For adequate three-dimensional assembly, biocompatible aligned nanofibers are beneficial as matrices for cell seeding. The aim of this study was to analyze the impact of Schwann cells (SC) on myoblast (Mb) and adipogenic mesenchymal stromal cell (ADSC) cocultures on poly-ɛ-caprolactone (PCL)-collagen I-nanofibers in vivo. Human Mb/ADSC cocultures, as well as Mb/ADSC/SC cocultures, were seeded onto PCL-collagen I-nanofiber scaffolds and implanted into the innervated arteriovenous loop model (EPI loop model) of immunodeficient rats for 4 weeks. Histological staining and gene expression were used to compare their capacity for vascularization, immunological response, myogenic differentiation, and innervation. After 4 weeks, both Mb/ADSC and Mb/ADSC/SC coculture systems showed similar amounts and distribution of vascularization, as well as immunological activity. Myogenic differentiation could be observed in both groups through histological staining (desmin, myosin heavy chain) and gene expression (MYOD, MYH3, ACTA1) without significant difference between groups. Expression of CHRNB and LAMB2 also implied neuromuscular junction formation. Our study suggests that the addition of SC did not significantly impact myogenesis and innervation in this model. The implanted motor nerve branch may have played a more significant role than the presence of SC.

Evaluation of selected properties of biocompatible chitosan/poly(vinyl alcohol) blends.

Selected properties of chitosan (CS) and poly(vinyl alcohol) (PVA) blends crosslinked by tetraethoxysilane (TEOS) were studied. XRD analysis showed characteristics peak at 22.5° attributed to the crystalline structure of CS and PVA. DSC thermograms unveiled the quantitative determination of free, intermediate and bound water in the blends. Tensile strength and fracture strain of blends were observed due to the combined effect of physically and chemically crosslinked network structures. The decrease in water contact angle indorsed the hydrophilic performance while the storage modulus G' and loss modulus G″ was decreased as the temperature was increased exhibited the viscoelastic property of the blends. The fabricated blends can be employed for drug delivery systems, tissue engineering and other biomedical applications.