Fabrication and characterization of two types of bone composites made of chitosan-genipin hydrogel and Bioglass 45S5

Synthetic inorganic-organic composites are of interest for bone tissue engineering as an alternative to natural grafts, since they resemble the structure of natural bone and degrade over time, enabling new bone to grow. In this study, properties of two types of composite materials: Type 1) genipin cross-linked chitosan hydrogels with the addition of Bioglass 45S5 (BG) powder and Type 2) BG scaffolds coated with the genipin cross-linked chitosan hydrogel, have been investigated using scanning electron microscopy (SEM), FTIR spectroscopy, fluorescence intensity (FI) measurement and compression tests. The composites were immersed in the simulated body fluid (SBF) for up to 2 weeks and their structure and mechanical properties were examined. Results showed that addition of BG powder to the chitosan hydrogels improved the compressive stress of the hydrogels both before and after immersion in SBF. However, the low values of the mechanical properties do not make them suitable for bone tissue applications. In the case of BG scaffolds coated with the chitosan-genipin hydrogel, the coating improved the mechanical properties of the scaffolds after immersion in SBF. Hydrogel coated BG scaffolds showed potential for low load-bearing applications, as an alternative to commonly used collagen and hydroxyapatite.