Permeability of bioceramic scaffolds

The assessment of porous scaffolds for bone tissue engineering (BTE) applications usually relies on factors such as porosity, pore size and distribution, and tortuosity, comparing them to the human bone reference values. However, these parameters cannot accurately describe the overall performance of bone scaffolds and only provide a preliminary comparison criterion. Permeability is proposed as a more significant parameter to characterize the scaffold architecture, as it is closely linked to the structural properties of the scaffolds and directly affects mass transport ability, influencing bone ingrowth. This chapter provides a comprehensive overview of porosity analysis in scaffolds, followed by an exploration of experimental and computational methods for permeability assessment, including pump-/gravity-based, acoustic, and numerical approaches. Both experimental and computational methodologies are discussed, highlighting advantages and limitations. However, the lack of universal and standardized measurement protocols makes it difficult to reliably compare the different results reported in literature about scaffold permeability assessment.