Potassium based bioactive glass for bone tissue engineering

A fundamental issue for the restoration of bone defects according to a tissue engineering approach is the development of highly porous bioactive scaffolds. The polymer burning out method is widely employed to fabricate bioceramic scaffolds because of its versatility, simplicity and low cost. However, the resulting scaffolds may suffer low porosity and non-interconnected pores. In the present contribution a new fabrication method is presented. Thanks to a recently developed potassium-based bioactive glass, which has the peculiarity to be sintered at a relatively low temperature (i.e. ∼750 °C), it was possible to use sodium chloride particles as pore generating agents, which helped to maintain the shape of the struts during the entire sintering process. The salt particles can be easily removed by immersing the scaffold in water, giving place to a structure that combines high porosity (in the 70-80 vol.% range) with interconnected pores and an appreciable mechanical behaviour (Young's modulus in the 3.4-3.7 MPa range according to compression tests).