Alternative methodology for chitin/hydroxyapatite composites using ionic liquids and supercritical fluid technology

An alternative, green method was used to develop chitin-based biocomposite (ChHA) materials by an integrated strategy using ionic liquids, supercritical fluid drying, and salt leaching. ChHA matrices were produced by dissolving chitin in 1-butyl-methylimidazolium acetate along with salt and/or hydroxyapatite particles and then subsequent drying. The ChHA composite formed had a heterogeneous porous microstructure with 65%–85% porosity and pore sizes in the range of 100–300 µm. The hydroxyapatite was found to be well distributed within the composite structures and had a positive effect in the viability and proliferation of osteoblast-like cells, in vitro. Our findings indicate that these ChHA matrices have potential applications in bone tissue engineering.Simone S. Silva and Miguel Oliveira received financial support from the Portuguese Foundation for Science and Technology-FCT (Grant SFRH/BPD/45307/2008 and SFRH/BPD/21786/2009, respectively), "Fundo Social Europeu"-FSE, and "Programa Diferencial de Potencial Humano-POPH." This work was partially supported by the FEDER through POCTEP 0330_IBEROMARE_1_P and European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. KBBE-2010-266033 (project SPECIAL)