The characteristic of injectability is crucial within the realm of biofunctional materials, enhancing their application in minimally invasive surgical procedures. In this context, bone cements, particularly magnesium phosphate cement (MPC), are prominently utilized due to their excellent resorption rates, high mechanical strength, and quick curing times, positioning them as strong competitors against traditional ceramic cements. Nonetheless, MPC is not without its challenges, including issues of brittleness, paste susceptibility to washout, and difficulties with injectability. This investigation focuses on the advantages of integrating alginate hydrogel into MPC, with the goal of improving its operational effectiveness and overall performance characteristics.
The synthesis of ceramic cement was executed through the combination of magnesium oxide and potassium dihydrogen phosphate (4:1 Mg/P molar ratio), incorporating varying concentrations of sodium alginate (SA) solutions as the liquid phases and adjusting powder-to-liquid ratios accordingly. The hydrogel was formed through a delayed cross-linking reaction using CaCO₃/GDL. Subsequently, the cement pastes were shaped and incubated under standardized conditions. Comprehensive assessments were performed, including evaluations of setting time and temperature, microstructure, chemical and phase composition, mechanical strengths, injectability, biodegradation, and cytocompatibility.
A novel dual-setting biocomposite cement was effectively created. The production of well-crystallized k-struvite crystals, showing significant variances in size and growth patterns, in conjunction with the cross-linked SA, was confirmed. Our analyses demonstrate numerous advantages of these new cements, such as decreased setting times, diverse microstructural configurations, improved biodegradability, and enhanced paste cohesion and injectability. Nevertheless, these advancements negatively impacted the composite's mechanical strength. Notwithstanding elevated bioreactivity, the cements retained cytocompatibility across most evaluated groups.
Acknowledgments
This research was supported by the Gdańsk University of Technology by the DEC-3/2022/IDUB /III.4.3/Pu grant under the PLUTONIUM 'Excellence Initiative – Research University program.
