Bioactive Ti–3Cu alloys with starch, mesoporous bioactive glass nanoparticles, and clove coating for enhanced orthopedic applications

Abstract

Orthopedic implants, especially titanium (Ti)-based materials, are essential in treating bone and joint injuries. However, pure Ti and conventional alloys often suffer from poor bioactivity and limited osseointegration. This study investigates the synthesis of Ti–3Cu alloys, optimized through sintering at 650 °C, 750 °C, and 850 °C, and enhanced by a composite bioactive coating comprising starch, mesoporous bioactive glass nanoparticles (MBGNs), and clove particles. XRD analysis revealed the presence of the α-Ti phase, with more pronounced Ti₂Cu peaks at 850 °C indicating phase formation associated with improved mechanical strength and antibacterial efficacy. Mechanical characterization showed that the substrate sintered at 750 °C exhibited the best combination of properties, with a microhardness of 91 HV and a density of 3.63 g cm⁻³, with porosity of 21.34%, a porosity and pore-size range known to facilitate bone ingrowth while minimizing stress shielding. The composite coating deposited via electrophoretic deposition (EPD) significantly improved surface wettability, reducing the contact angle from 133.13° ± 15.51° for the uncoated substrate to 62.67° ± 6.98° for the coated substrate. Antibacterial tests revealed the clove extracted-coated Ti–3Cu alloy exhibited moderate inhibition zones of 1.23 cm for Escherichia coli and 1.38 cm for Staphylococcus aureus. Bioactivity studies showed progressive formation of hydroxyapatite (HA), with a Ca/P ratio increasing from 1.25 on day 7 to 1.51 on day 21, indicating mature mineralization. Biodegradability testing in simulated body fluid (SBF) showed that the composite coating degraded 53.71% by day 21. Cytocompatibility tests revealed enhanced cell viability, with 104.91% cell viability on day 7 for the composite-coated substrate. These results demonstrate the Ti–3Cu alloy with composite coating, offering improved mechanical properties, antibacterial activity, bioactivity, and cellular compatibility, has potential in orthopedic applications.