Quantifying the micro-architectural similarity of bioceramic scaffolds to bone

Porous bioceramics for bone repair should ideally mimic the micro-architectural characteristics of bone and promote the growth of regenerated tissue inside their pores. Assessment of the similarity between scaffold and bone in a quantitative and reliable way still remains an open challenge that we tackled in this work. We produced glass-ceramic scaffolds with two different nominal porosities by polymer sponge replication and characterized their three-dimensional architecture through non-destructive X-ray micro-computed tomography. Six key independent features were measured, namely total porosity, pore interconnectivity, pore size distribution, specific surface area, connectivity density and degree of anisotropy. In order to enable quantitative and objective comparison between bioceramic scaffolds and bone, each of the above-mentioned independent characteristics measured in the scaffold was compared to the corresponding feature in human trabecular bone. A multiparametric score, which comprises all the estimated features, was also developed and used to evaluate the similarity between the produced scaffolds. These quantitative comparisons can allow researchers to identify reliably the scaffold that more closely resembles the bone micro-architecture, suggesting the possible use of this approach to guide the design, manufacturing and selection of biomimetic ceramic scaffolds.