Chitosan/silk fibroin biomimic scaffolds reinforced by cellulose acetate nanofibers for smooth muscle tissue engineering

Reconstruction of multilayered and functional smooth muscle tissues remains a challenge nowadays. Cryogels possess great advantages in three-dimensional tissue regeneration owing to the interconnected macroporous structure, but their applications have been hindered because of limited mechanical properties. Inspired by the natural extracellular matrix, cellulose acetate electrospun nanofibers (NFs) were incorporated to chitosan/silk fibroin (CS/SF) cryogel scaffolds to address this problem in this work. Compared with pure CS/SF scaffolds, CS/ SF/NFs composite scaffolds showed roughened surface and enlarged pore size (216.2 +/- 65.3 mu m vs. 263.1 +/- 75.7 mu m) allowing for cell adhesion and proliferation. Incorporation of nanofibers upgraded the mechanical properties of scaffolds with a six-fold increase in compressive modulus. The proliferation and infiltration of smooth muscle cells (SMCs) were remarkably improved with the existence of nanofibers. Besides, SMCs cultured on CS/SF/NFs scaffolds displayed higher expression of contraction-related genes, verifying their potential for smooth muscle tissue engineering.