Effects of ZnO/SrO/akermanite incorporation on the microstructure, mechanical properties, andin vitroosteogenic...

To address the inherent brittleness ofβ-tricalcium phosphate (β-TCP) bioceramics, we incorporated ZnO, SrO, or bioactive glass (AK) into aβ-TCP matrix. Porous scaffolds were fabricated via digital light processing and sintering. X-ray diffraction confirmed the preservation of theβ-TCP phase, and SEM revealed a multiscale porous architecture with uniform macropores (∼400 μm) and submicron surface micropores specifically in theβ-TCP/AK composite. This scaffold exhibited the most balanced performance: its compressive strength increased by ∼38% to 9.65 MPa compared to pureβ-TCP. During immersion in simulated body fluid, theβ-TCP/AK scaffold induced a favorable alkaline pH, exhibited the highest degradation rate (mass loss), and enabled sustained release of bioactive Si⁴⁺and Mg²⁺ions, which enhanced apatite mineralization.In vitro, all modified scaffolds promoted osteoblast proliferation. Notably, theβ-TCP/AK scaffold most significantly stimulated osteogenic differentiation, elevating ALP activity to 2.48 ± 0.184 (vs. 1.87 ± 0.126 for pureβ-TCP) and upregulating key osteogenic genes (ALP, OCN, RUNX2). These results demonstrate that AK doping optimally enhances the mechanical strength, biodegradation, ion release, and osteogenic capacity ofβ-TCP, presenting a highly promising composite for bone tissue engineering.