Tough and hierarchical porous cryogel scaffolds preparation using n-butanol as a non-solvent

Hierarchical porous chitosan cryogels were prepared by combination of cryogelation and phase separation techniques. n-Butanol was included as a non-solvent in the initial polymer solutions to enable phase separation. The internal morphology of the resulting cryogels revealed hierarchical porosity where larger pores of between 25–50?µm were formed via cryogelation, whereas smaller pores of between 4–10?µm were produced by phase separation. The control sample prepared without n-butanol exhibited monotype porosity. Any crack development was not observed when samples were compressed up to 80% strain. The results demonstrated hierarchical porous and tough scaffolds with potential use in tissue engineering.