Silver-loaded microspheres reinforced chitosan scaffolds for skin tissue engineering

In order to improve the mechanical properties and antibacterial properties of skin tissue engineering scaffolds, a microspheres-reinforced composite construct with controlled release property was designed. The silver-loaded chitosan (CS) microspheres (Ag@CMs) were prepared by emulsified crosslinking method. Ag@CMs were introduced into CS acetic acid solution and then Ag@CMs embedded porous CS scaffolds were fabricated by lyophilization method. The results show that Ag@CMs are uniformly distributed inside porous CS scaffolds and there is no significant effect on the structure of the pores. The Ag@CMs/CS composite scaffolds possess high porosity (66.03 +/- 0.15) %. The compressive strength and modulus of the composite scaffold reach up to 0.47 +/- 0.03 MPa and 3.95 +/- 0.06 MPa, respectively, significantly higher than pure CS scaffold. The in vitro drug delivery tests and antibacterial activity tests illustrate that composite scaffolds have efficient antibacterial properties and excellent drug sustained-release performance. MTT assay indicates that Ag@CMs/CS porous scaffold can provide an interconnected porous structure and large surface area for mouse fibroblast cell (L929) adhesion and proliferation. These results suggest that Ag@CMs/CS porous scaffold is a promising candidate for skin tissue engineering.