Multifactorial design considerations for 3D-Printed PCL-CaCO3 bone graft scaffolds: mechanical, degradation, and electrical field-related aspects

Bone graft substitutes are required to provide sufficient mechanical stability while accommodating additional physical stimuli supporting osteogenic differentiation, such as externally applied electric fields. This work investigates a 3D-printed polycaprolactone composite scaffold from a materials design perspective. Key design parameters, namely incorporated CaCO 3 particle morphology and specific surface area, scaffold pore geometry, and precipitated CaCO 3 coating, were characterized with respect to compression and degradation tests. In parallel, the spatial distribution of externally applied electric fields within the scaffold architecture were analyzed using in silico modeling and complemented by preliminary in vitro experiments. The results indicate that increasing particle specific surface area enhances compressive stability while decelerating degradation. The CaCO 3 coating improves overall structural integrity, yet eliminates the degradation-tuning effects of the CaCO 3 particle morphologies. With regard to the scaffold pore geometry, triangular pores were identified as being favorable from a degradation standpoint. Contrary, electric field simulations indicate a broader spatial distribution in spectral pores, accompanied by indicated osteogenic response of human mesenchymal stem cells. Overall, the study underscores the significance of trade-off decisions in the development of bone graft substitutes between mechanical performance, degradation behavior, and electric field distribution. This work emphasizes the necessity of multifactorial considerations in scaffold design.