Silver-Doped Mesoporous Bioactive Glass Nanoparticles With Core-Shell Architecture: Enhanced In Vitro Bioactivity,...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Regenerative Medicine

Background:

• Orthopedic biomaterials face a dual challenge: preventing infection and promoting bone regeneration.
• Bioactive glass nanoparticles (BGNs) offer potential but require precise control over ion release for optimal performance.
• Tuning silver-ion (Ag+) and calcium-ion (Ca2+) release is crucial for balancing antibacterial and osteogenic properties.

Purpose of the Study:

• To design and synthesize novel BGNs with tailored nanoarchitectures.
• To decouple and control the release of Ag+ and Ca2+ ions.
• To evaluate the antibacterial, osteogenic, and biocompatibility profiles of the engineered BGNs.

Main Methods:

• Synthesis of four BGN types using a modified sol-gel route, including solid spheres and core-shell mesoporous structures.
• Introduction of silver during synthesis and calcium impregnation for core-shell architectures.
• Characterization using electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller analysis, and inductively coupled plasma mass spectrometry.
• In vitro evaluation of mineralization, antibacterial activity against Staphylococcus aureus and Escherichia coli, and human mesenchymal stem cell response.
• In ovo biocompatibility testing using the Hen's Egg Test on the Chorioallantoic Membrane (HET-CAM).

Main Results:

• Mesoporous BGNs exhibited significantly higher surface area (≈860 m²/g) compared to solid spheres (≈17 m²/g).
• Core-shell architectures facilitated sustained Ag+ and Ca2+ release over 21 days at low concentrations.
• Ag-doped mesoporous BGNs demonstrated potent antibacterial activity and enhanced bone mineralization.
• These BGNs supported human mesenchymal stem cell viability and osteogenic differentiation.
• No vascular irritation was observed in the HET-CAM assay, indicating good biocompatibility.

Conclusions:

• Nanostructural engineering, specifically combining mesoporosity and core-shell architectures, optimizes ion release from BGNs.
• This approach successfully balances antibacterial efficacy with osteogenic support for orthopedic applications.
• The developed multifunctional nanoglasses hold significant promise for regenerative and antimicrobial therapies.