Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Nanotechnology

Background:

• Calcium phosphate bone cements (CPCs) are vital in orthopedic applications.
• There is a clinical demand for CPCs with enhanced antibacterial properties.
• Silver doping is a strategy to impart antimicrobial efficacy to bone cements.

Purpose of the Study:

• To develop and characterize silver-doped calcium phosphate bone cements (CPCs-Ag).
• To investigate the structural transformations and kinetics of CPCs-Ag formulations.
• To evaluate the antibacterial activity and mechanical properties of CPCs-Ag.

Main Methods:

• Preparation of silver-doped CPCs (CPCs-Ag) via a solid dispersed active powder phase route.
• Real-time structural monitoring using Energy Dispersive X-ray Diffraction (EDXRD).
• Assessment of compressive strength, silver-ion release (Atomic Emission Spectroscopy), and antibacterial efficacy against Escherichia coli.

Main Results:

• CPCs-Ag formulations showed partial conversion of β-tricalcium phosphate (TCP) to dicalcium phosphate dihydrate (DCPD).
• Metallic silver was present in pristine powders, while CaAg(PO₃)₃ formed in doped cements.
• Compressive strength decreased with increasing silver content (6.5 MPa for 0 wt% Ag to 1.5 MPa for 1.0 wt% Ag).
• Silver-ion release increased with silver content (25 µg/L for 0.6 wt% Ag, 43 µg/L for 1.0 wt% Ag).
• CPCs-Ag demonstrated significant inhibitory effects against Escherichia coli, with higher efficacy at greater silver concentrations.

Conclusions:

• The developed CPCs-Ag exhibit antibacterial properties, making them suitable for bone regeneration applications.
• The trade-off between antibacterial efficacy and mechanical strength needs consideration for optimal clinical use.
• Further research can focus on optimizing silver content for enhanced performance and biocompatibility.