The use of ionic liquids in the processing of chitosan/silk hydrogels for biomedical applications

Natural polymers are adequate renewable resources for the processability of well-defined architectures for several applications. Combinations of polysaccharides and proteins may mimic the naturally occurring environment of certain tissues. The main goal of this work renders the application of green chemistry principles, namely the use of ionic liquids (ILs) and biorenewable sources, such as chitosan (CHT) and silk fibroin (SF), to process new hydrogel-based constructs. Although the solubilization of both materials in ILs has been studied individually, this work reports, for the first time, the role of ILs as solvent, for the production of hydrogels from blends of chitosan and silk fibroin (CSF). These systems offer the advantage of being homogeneous and presenting easy and short dissolution time of both biomacromolecules. Moreover, the use of chitosan obtained from alpha- and beta-chitin allowed the production of blended hydrogels with distinct physical-chemical properties. In vitro assays demonstrated that these hydrogels supported the adhesion and growth of primary human dermal fibroblasts. Taken these properties together, the CSF hydrogels might be promising biomaterials to be explored for skin tissue engineering approaches.