Analysis of the Multiwalled Carbon Nanotubes Reinforced Polymethyl Methacrylate Bone Cement’s Characteristics and In Vitro Bioactivity to Prolong Its Functionality in Orthopedic Application

Polymethyl methacrylate (PMMA) bone cement is being used to fill voids that are created due to vertebral compression fractures. It is also a grouting medium in orthopedic joint replacement surgeries as they possess fast primary fixation to the bone. Considering the cement properties and in vitro bioactivity of bone cement is essential for cemented hip and knee joint replacement surgeries. In this study, commercial Simplex P bone cement (SPBC) is modified with carboxyl- (-COOH-) functionalized multiwalled carbon nanotubes (MWCNTs) to overcome high polymerization temperature, volumetric shrinkage, surface wettability, and in vitro bioactivity. A geometric dilution method is used to incorporate MWCNTs with the PMMA powder, which is in unequal proportions. The PMMA/MWCNT nanocomposite with different concentrations of reinforcements, such as 0.1, 0.3, 0.5, and 0.7 weight percentages, is prepared for the investigation. It was observed that the MWCNTs had a beneficial impact on PMMA bone cement (PMMA-BC) by enhancing its setting time (2.94%↑) and surface wettability (23.58%↑). Also, diminished polymerization temperature (29%↓) and volumetric shrinkage (40.9%↓) are observed for an optimum concentration of 0.7 wt. %. The bioactivity of the cement surface is validated by the in vitro bioactivity observed in simulated body fluid (SBF) through the development of primary and secondary apatite. It is concluded that the synthesized PMMA/MWCNT nanocomposites are found to have enhanced cement properties compared to PMMA-BC.