Strontium-substituted hydroxyapatite reinforced 3D-printed potato starch scaffolds for in vitro biological response evaluation

The aim of this study was to evaluate the feasibility of fabricating biocompatible scaffolds based on a potato starch matrix reinforced with hydroxyapatite and strontium-substituted apatites using extrusion-based 3D printing. The minerals synthesized by the wet route exhibited nanoscale morphological features, as observed by SEM, while XRD and FTIR confirmed the expected apatite phases. Strontium substitution induced lattice distortion and reduced crystallinity, which influenced ion release behavior. Rheological analysis confirmed pseudoplastic behavior, supporting adequate printability and structural stability during the printing process. The incorporation of strontium contributed to increased mechanical strength, reaching values up to 45.8 kPa. The scaffolds exhibited limited degradation over 21 days, indicating suitability for applications requiring temporary structural support. ICP-MS analysis confirmed sustained Sr 2+ release, which may contribute to bioactive responses. In vitro biological assays indicated increased osteoblast metabolic viability and a possible reduction in osteoclast-related activity, although these observations are based on preliminary and partially qualitative analyses. Therefore, these results suggest the potential of starch-based composite scaffolds incorporating strontium-substituted apatites as a promising platform for bone tissue engineering applications. However, further in vitro and in vivo studies are required to validate these findings and assess the long-term biological performance of the developed scaffolds.