Enhancing Osseointegration in Bone Cement Through Synergistic Biocomposite Formulations

This study aimed to overcome the limitations of conventional polymethylmethacrylate (PMMA) bone cement, such as low wear resistance, aseptic loosening, and poor osteoconductivity, by formulating enhanced composites incorporating Zirconia (ZrO₂)-Zr, Collagen, and Calcium Phosphate (Ca₃(PO₄)₂)-CaP. The research question was whether these additives could synergistically improve the mechanical, thermal, and biological performance of PMMA bone cement for orthopedic applications.

Three composite variants-PMMA-Zr-CaP (6:1:1), PMMA-Zr-Collagen (4:1:1), and PMMA-Zr-Collagen (2:1:1)-were synthesized through powder dispersion, in situ polymerization, and sintering. Characterization included FTIR for chemical structure, XRD for crystallinity, SEM for morphology, and TGA for thermal stability. Mechanical properties were assessed via compressive strength and fracture toughness testing, and in vitro cytotoxicity was evaluated using cell viability assays.

Zirconia significantly increased compressive strength by 25-30% and fracture toughness by ~ 28% (p < 0.05) compared to unmodified PMMA. Collagen and CaP enhanced bioactivity and osseointegration potential, evidenced by increased surface roughness and porosity in SEM analysis. TGA revealed improved thermal stability and a lower polymerization temperature (65-75 °C). The PMMA-Zr-Collagen (4:1:1) formulation demonstrated the highest cell viability (> 85%, p < 0.05).

The incorporation of ZrO₂, Collagen, and CaP into PMMA bone cement creates mechanically robust, thermally stable, and biologically active composites. These formulations present a promising approach to extending implant longevity and reducing complications associated with traditional bone cement in orthopedic surgeries.