Within the biomedical field, alternatives to natural bone are essential for repairing significant bone breaks that require rebuilding. Injectible, self-hardening bone cements like magnesium phosphate (MPC) are integral to orthopedic operations with minimal invasiveness. These biomaterials are valued for their biodegradable qualities, quick setting, and good mechanical strength, equating them with traditional bone substitutes such as calcium phosphates. However, there is a noted deficiency in the cohesion and ease of injection of MPC paste. This research delves into creating a novel functional biocement based on MPC enhanced with a poly(vinyl alcohol) (PVA) hydrogel to improve its application.
This biocomposite cement results from combining magnesium oxide with potassium dihydrogen phosphate in a PVA-based matrix. The study examines hydrogel’s impact by varying its concentrations and different content of cross-linking agent. The evaluation encompasses assessments of setting time and temperature, microstructural examination, identification of phases and chemical composition, static strength testing, injectability potential, and a cytocompatibility evaluation with human osteoblasts.
This research has culminated in the creation of a unique dual-setting bone cement, which merges magnesium phosphate cement with poly(vinyl alcohol) hydrogel. This novel biocomposite is characterized by exceptional attributes such as superior biocompatibility, proper biodegradation and improved functional qualities, reducing negative physiological responses and enhancing safety for clinical use. Furthermore, the material demonstrates
a reduced setting temperature, good porosity and enhanced injectability - allowing for more precise and minimally invasive surgical procedures. Consequently, this innovative biocement holds great potential for advancing orthopedic and trauma treatments.

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.