A New Approach to Design Hydroxyapatite and Silk Fibroin Bone Substitutes

Abstract

Biomaterials to regenerate bone have been gaining great visibility in tissue engineering. The design of a material like bone is a great challenge, especially when combining the ideal mechanical strength, porosity, and bioactivity. This work focused on the development of a new candidate for bone substitute combining hydroxyapatite (HAp) and silk fibroin (SF). The silk fibroin, obtained from the cocoons of the silkworm (Bombyx mori), was dissolved using a ternary solution of calcium, ethanol, and water. HAp was co-precipitated dropping phosphate solution (Na2HPO4) in SF at a constant stirring. The final composite, 75%HAp/25%SF, were framed using a hydraulic system varying the pressure to find the best candidate. Physical and chemical characterizations were evaluated, as well as the bioactivity and cytotoxicity. Results showed excellent chemical and physical properties, like the trabecular bone. The 75%HAp/25%SF biocomposite was safe to CHO cells and presented great bioactivity being an alternative candidate to the bone regeneration field.