Zinc- and Fluoride-Releasing Bioactive Glass as a Novel Bone Substitute

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Regenerative Medicine

Background:

• Bioglass 45S5, a silica-based biomaterial, promotes mineralization but causes inflammation and has limited degradation for bone grafting.
• Phosphate-based glasses offer higher solubility and ion release, with synthesis flexibility for doping therapeutic metal oxides.

Purpose of the Study:

• To fabricate novel zinc- and fluoride-doped phosphate-based bioactive glasses (MP and 4% Al-MP) to improve upon Bioglass 45S5 for bone regeneration.
• To evaluate the stability, ion release, osteogenic potential, anti-inflammatory effects, and bone regeneration capacity of the developed glasses.

Main Methods:

• Fabrication of multicomponent phosphate (MP) bioactive glass doped with zinc and fluoride, and further aluminum oxide (4% Al-MP glass).
• Assessment of glass dissolution, ion release (Zn, F), particle size, and stability in water.
• In vitro evaluation of osteogenesis in mouse bone marrow-derived mesenchymal stem cells and macrophage polarization (M1/M2).
• In vivo assessment of bone regeneration in a mouse calvarial defect model.

Main Results:

• MP glass showed increased zinc and fluoride ion release.
• 4% Al-MP glass exhibited suppressed dissolution, enhanced stability in water, and reduced particle size, facilitating abundant ion release.
• 4% Al-MP glass significantly enhanced osteogenesis and promoted M2 anti-inflammatory macrophage polarization.
• In vivo, 4% Al-MP glass promoted significantly greater bone regeneration than Bioglass 45S5.

Conclusions:

• Successfully developed zinc- and fluoride-releasing bioactive glasses with improved osteogenic and anti-inflammatory properties.
• The 4% Al-MP glass demonstrates superior performance over Bioglass 45S5 for bone regeneration applications.
• These novel glasses represent promising biomaterials for enhanced bone repair and regeneration.