Surfactant-stabilized emulsion increases gentamicin elution from bone cement.

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Infectious Disease Control

Background:

• Liquid antimicrobial incorporation into bone cement is challenging due to reduced mechanical strength and limited loading capacity.
• Emulsification of liquid antimicrobials into the cement monomer offers a potential solution to these limitations.

Purpose of the Study:

• To evaluate the impact of surfactant-stabilized emulsions on antimicrobial release, compressive strength, and porosity of bone cement.
• To compare emulsified antimicrobial-loaded bone cement with traditional powder-based formulations.

Main Methods:

• 144 standardized bone cement cylinders were prepared: 72 with emulsified antimicrobial and 72 with antimicrobial powder.
• Gentamicin release was measured over 30 days under infinite sink conditions.
• Compressive strength was tested at 0, 1, and 30 days of elution.
• Porosity was analyzed using scanning electron microscopy.

Main Results:

• Emulsified bone cement demonstrated a fourfold increase in antimicrobial release compared to the control.
• Initial compressive strength of emulsified cement was lower (58.1 MPa) than control (81.3 MPa).
• Emulsified cement's strength remained stable during elution, while control cement strength decreased over 30 days.
• Both formulations exhibited homogeneous porosity around 50 μm.

Conclusions:

• Emulsified antimicrobial-loaded bone cement achieves enhanced drug release and homogeneous porosity.
• Despite improved release, the significant reduction in compressive strength limits its current application in implant fixation.
• Further research is required to enhance the mechanical properties of emulsified bone cement for clinical viability.