23rd EFORT Annual Congress - EFORT 2022, Lisbon (Portugal). 22-24 June 2022
Summary:
Two-stage exchange with antibiotic-loaded bone cement spacers remains the gold standard for chronic periprosthetic infection. Rifampicin is highly efficient on stationary-phase staphylococci in biofilm; however, its addition to PMMA to manufacture spacers prevents polymerization and reduces mechanical properties. Isolation of rifampicin during polymerization by microencapsulation, which could allow manufacturing rifampicin-loaded bone cement maintaining elution and mechanical properties.
Microcapsules of rifampicin with alginate, polyhydroxybutyrate (PHBV), ethylcellulose and stearic acid were synthesized. Rifampicin elution to phosphate buffer was measured by UV-visible spectroscopy. Alginate and PHBV microcapsules were added to bone cement CMW®1 and elution,
compression, bending, hardness and setting time tests were performed. Antimicrobial activity was assessed by disk diffusion test with S.aureus ATCC®29213TM. Repeated measures ANOVA and Bonferroni post-hoc test using SPSS version 22.0 were performed, considering a p<0.05 as statistical significance.
Alginate microcapsules showed the highest rifampicin elution (p=0.0001). Bone cement specimens containing alginate microcapsules eluted more rifampicin than PHBV microcapsules or non-encapsulated rifampicin over time (p<0.012). Addition of microcapsules to PMMA did not significantly alter the bending modulus compared to control cement (p=1). Cement with alginate microcapsules showed similar behavior in hardness tests to control cement over the study period (73±1.68HD), reaching the maximum hardness within 15 minutes. Microencapsulated rifampicin preserved its antimicrobial properties. Statistically significant differences in mean values of diameters of zones of inhibition between alginate-rifampicin (p=0.0001) and alginate-PHBV (p=0.0001) were detected.
Keywords: Rifampicin-Loaded Bone Cement, Rifampicin Microencapsulation, Bone Cement Spacers, Periprosthetic Infection.
Publication date: 2022-06-22.
Citation:
E. Carbó-Laso, P. Sanz-Ruiz, J. Vaquero-Martín, I. López-Torres, M.C. Solans-López, J.C. del Real-Romero, F. Arán-Ais, Y. Ballesteros, E. Paz, Rifampicin-loaded polymethylmethacrylate: is it possible to preserve mechanical properties and setting time?, 23rd EFORT Annual Congress - EFORT 2022, Lisbon (Portugal). 22-24 June 2022.
