Modified Cyclodextrin Microparticles to Improve PMMA Drug Delivery Without Mechanical Loss

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Drug Delivery Systems

Background:

• Poly(methyl methacrylate) (PMMA) cement is used for local antibiotic delivery in orthopedic infections.
• Current PMMA systems show inefficient drug release, declining to subinhibitory levels.
• Incorporating drug-filled cyclodextrin (CD) microparticles improves release consistency but reduces mechanical strength.

Purpose of the Study:

• To synthesize and evaluate modified cyclodextrin (PMMA-CD) microparticles.
• To assess the impact of PMMA-CD on the mechanical properties and drug delivery of PMMA bone cement.
• To investigate the refilling capability of PMMA cement containing PMMA-CD.

Main Methods:

• Synthesis of PMMA-CD microparticles with covalently appended PMMA chains.
• Evaluation of compressive strength, handling characteristics (working time, polymerization temperature), and drug refilling ability.
• Comparison of PMMA cement with PMMA-CD against plain PMMA and PMMA with unmodified CD.

Main Results:

• PMMA cement with 10 wt% PMMA-CD showed a 13.7% increase in compressive strength compared to unmodified CD.
• Working time increased by 13.3%, and maximum polymerization temperature decreased by 7.5%.
• Drug refilling amount increased by up to 32.1% with PMMA-CD compared to plain PMMA.

Conclusions:

• PMMA-CD microparticles mitigate the mechanical strength reduction typically seen with CD incorporation in PMMA.
• The modified microparticles enhance drug delivery consistency and refilling efficiency.
• PMMA-CD represents a promising advancement for antibiotic delivery in orthopedic applications, improving both mechanical integrity and therapeutic efficacy.