Preparation, Characterization and Evaluation of a Poly Methyl Methacrylate Bone Cement Modified by Montmorillonite Loaded with Silver Nano Particles

Purpose: The aim of this study was to prepare and characterize poly methyl methacrylate (PMMA) composite bone cement filled with montmorillonite (MMT) and loaded with silver nanoparticles (AgNPs). Materials and methods: AgNPs were synthesized by the chemical reducing method. Characterization was done using Field emission scanning electron microscope (FE-SEM), X-ray diffraction analysis (XRD) and Thermogravimetric analysis (TGA). Two and four weight percentages of MMT powder and the prepared MMT/AgNPs powder were added to the bone cement. A total of 75 PMMA bone cement specimens were prepared and divided into 5 groups (control group, PMMT/MMT 2%, PMMT/MMT 4%, PMMT/MMTAgNps 2% and PMMT/MMTAgNps 4%). Then they were tested regarding the compressive strength, flexural strength and antibacterial activity. Results: SEM images showed the layered MMT with light spots indicating presence of AgNPs that was confirmed by XRD; while TGA showed its thermal stability. Compressive strength results revealed statistically insignificant difference between the control and the tested groups while the 4% PMMA/MMT showed statistically significant higher values than the 2%. Statistically insignificant difference in flexural strength results were found between the 2% and 4% concentrations within the PMMA/ MMT/AgNPs group, and within the PMMA/MMT group. Antibacterial results revealed statistical significant differences in all the tested groups (p<0.001). Conclusion: MMT could be used as a controlled delivery system to hold AgNPs that proved to have antibacterial effect when added to PMMA cement. Addition of 4% MMT to PMMA bone cement improved its compressive strength.