Lithium-Doped Mesoporous Bioactive Glass with Dual Antibacterial Mechanisms: Sustained Ion Release and Osteogenic Activity for Bone Regeneration

Infected bone regeneration faces challenges from biofilm resistance and antibacterial material trade-offs. To resolve this, we synthesized lithium-doped mesoporous bioactive glass microspheres (7Li-MBGs) via sol-gel precursor sequence modulation. This optimization maintained structural integrity (~500   nm diameter, 2-5   nm pores) while enhancing long-term antibacterial efficacy (> 90% against S. aureus / E. coli over 14 days). A dual-mechanism strategy operates: Non-ROS lithium release dominates early-phase (1-7 days) bactericidal action via membrane disruption and metabolic interference; controlled ROS-boosted reinforcement sustains late-phase (7-14 days) activity below safety thresholds without osteogenic suppression. Simultaneously, 7Li-MBGs enhance osteoblast ALP activity with safe degradation (14-day Li + release: 5 ppm, << nephrotoxicity limit). This synergy overcomes the trade-off between sustained antibacterial efficacy, biosafety, and osteogenic compatibility in bone repair materials.