High-reliability data processing and calculation of microstructural parameters in hydroxyapatite scaffolds produced by vat photopolymerization

The accurate determination of mass transport and microstructural properties within highly-porous trabecular bone specimens and substitutes still represents a challenge due to the complex arrangement in the three-dimensional space, where adjacent pores can be hardly identified due to the open-cell disordered structure resulting from the reciprocal alternation of struts and voids. In the present study, the complete set of mass transport properties of hydroxyapatite (HA) scaffolds produced by digital light processing (DLP)-based vat photopolymerization was determined by applying the recent Ergun-Wu resistance model. Input data include the intrinsic permeability of the scaffolds, obtained by acoustic experimental measurements, and the equivalent pore diameter, calculated as a function of total porosity and average trabecular size from accurate micro-computed tomography (mu-CT) scans. The results, corroborated by an accurate and robust statistical analysis, were compared with previous literature data and confirmed a feasible and concrete application of DLP-derived HA scaffolds in clinical practice.