Phase‐Engineered Li‐ and B‐Containing Calcium Phosphate/Silicate Scaffolds for Bone Regeneration

The development of advanced bioactive ceramics capable of promoting bone regeneration requires suitable compositions that modulate both ion release and surface reactivity. Herein, green scaffolds comprising a C 2 S core and outer Ca 4 Li 4 (PO 4 ) 4 ‐based coating layers containing (Li + ) and borate (BO 3 3− ) species were developed. After sintering, the initial multilayer architecture evolved into multiphasic calcium phosphate/silicate scaffolds due to interdiffusion and reaction between the precursor phases. BO 3 3− species were introduced in the initial formulation at 0%, 15%, and 30%, and the effect of chemical etching on the bioactivity of the scaffolds was evaluated. Physicochemical characterization (X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), field emission scanning electron microscopy/energy dispersive X‐ray spectroscopy (FESEM/EDX), and porosimetry) revealed that BO 3 3− addition promoted the formation of bioactive phases such as Ca 9.93 (P 5.84 B 0.16 O 24 )(B 0.67 O 1.79 ) and Ca 5 P 3 O 13 , while chemical etching enhanced surface roughness and early HA‐like precipitation. Bioactivity tests in simulated body fluid (SBF) suggested the formation of Ca–P precipitates with HA‐like morphology/composition in B‐containing. In vitro biocompatibility assays using 3T3 fibroblasts demonstrated that all scaffolds tested— 0BC , 15BC , 15BC‐3d , and 15BA‐3d —were noncytotoxic, and that Ca, Li, Si, P, and B ions supported cell viability. Notably, the 15BA‐3d scaffold exhibited the highest metabolic activity and enhanced cell adhesion, likely due to the synergistic release of ions and presence of surface hydroxyapatite‐like deposits. Phase‐engineered Li‐ and B‐containing calcium phosphate/silicate scaffolds exhibit promising characteristics for application in bone tissue engineering.