A Bioactive Degradable Composite Bone Cement Based on Calcium Sulfate and Magnesium Polyphosphate

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Regenerative Medicine

Background:

• Calcium sulfate bone cement (CS) is widely used for bone repair due to its self-setting and degradable nature.
• Limitations of conventional CS include rapid degradation, poor mechanical strength, and inadequate biological activity.
• There is a need for advanced bone cements with improved properties for enhanced bone regeneration.

Purpose of the Study:

• To develop and characterize a novel composite bone cement based on calcium sulfate, magnesium polyphosphate (MPP), and tricalcium silicate (C3S).
• To evaluate the physical, mechanical, and biological properties of the optimized composite bone cement (CS/MPP/C3S).
• To assess the potential of the composite bone cement for improved bone repair applications.

Main Methods:

• A composite bone cement was formulated using calcium sulfate (CS), magnesium polyphosphate (MPP), tricalcium silicate (C3S), and hydroxypropyl methylcellulose (HPMC).
• The setting time, compressive strength, and injectability of the composite bone cement were measured.
• In vitro biocompatibility and osteogenic potential were assessed through cell proliferation assays and the quantification of osteogenic gene expression (Runx2, BMP2, OCN, OPN, COL-1) and alkaline phosphatase activity.

Main Results:

• The optimized CS/MPP/C3S composite bone cement exhibited a suitable setting time of ~15.0 min, compressive strength of 26.6 MPa, and injectability of ~93%.
• The composite demonstrated excellent biocompatibility, with cell proliferation increasing up to 114% compared to the control after 5 days.
• Significant upregulation of osteogenic gene expression (Runx2, BMP2, OCN, OPN, COL-1) and alkaline phosphatase activity was observed after 14 days, indicating enhanced osteogenesis.

Conclusions:

• The developed CS/MPP/C3S composite bone cement effectively overcomes the limitations of traditional calcium sulfate bone cement.
• The composite exhibits promising mechanical properties, excellent biocompatibility, and superior osteogenic capabilities.
• This novel composite bone cement holds significant potential for advanced applications in bone repair and regeneration.