Low‐temperature sintered boron‐doped S53P4 bioactive glass scaffolds fabricated by robocasting

Abstract This study investigates boron‐doped S53P4 bioactive glass (BG) scaffolds fabricated via robocasting in the context of bone regeneration strategies by comparing their mechanical performance and bioactive behavior to undoped S53P4 BG scaffolds. Three‐dimensional scaffolds with grid‐like macro architectures were fabricated using gelatin‐based composite inks containing S53P4 BG and 10 wt.% boron‐doped S53P4 BG (S53P4_10B). The scaffolds were sintered at optimized temperatures (900°C for S53P4 and 615°C for S53P4_10B), resulting in an average volumetric shrinkage of 33 vol%. Both scaffold types exhibited high porosity (∼71%) with pore sizes of 584 ± 7 µm (S53P4) and 608 ± 25 µm (S53P4_10B). Compressive strength values of 3.3 ± 1.7 MPa and 1.5 ± 0.4 MPa were respectively measured for S53P4 and for S53P4_10B BG scaffolds. Soaking in simulated body fluid for 14 days resulted in complete surface coverage with calcium‐phosphate‐rich phases, indicating high bioactivity. Antibacterial tests revealed that while crystallization reduced the inhibition zone of S53P4 scaffolds, S53P4_10B scaffolds exhibited significant antibacterial activity against E. coli and S. aureus . Cytocompatibility tests using MG‐63 and ST‐2 cell lines confirmed that scaffold extracts at concentrations ≤1% w/v were noncytotoxic. These results show that boron‐doped BG scaffolds possess bioactivity, antibacterial efficacy, and cytocompatibility, and suggest that their mechanical performance can be further tuned through scaffold design and sintering conditions.