A Novel Injectable Magnesium/Calcium Sulfate Hemihydrate Composite Cement for Bone Regeneration

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Regenerative Medicine

Background:

• Calcium sulfate hemihydrate (CSH) is a common bone void filler.
• Limitations of CSH include rapid setting time and suboptimal mechanical properties.
• There is a need for improved injectable bone scaffolds for bone defect repair.

Purpose of the Study:

• To develop and characterize a novel injectable magnesium/calcium sulfate hemihydrate (Mg/CSH) composite.
• To evaluate the in vitro and in vivo performance of the Mg/CSH composite for bone tissue engineering applications.

Main Methods:

• Mg/CSH composite properties (setting time, injectability, compressive strength, bioactivity) were assessed.
• Degradability in simulated body fluid (SBF) was evaluated.
• Cellular responses (attachment, proliferation, osteogenic differentiation) of canine bone marrow stromal cells (cBMSCs) to Mg/CSH were investigated.
• In vivo bone formation was evaluated in canine tibia defects after Mg/CSH implantation.

Main Results:

• Mg/CSH exhibited prolonged setting time, improved injectability, and enhanced mechanical properties compared to CSH.
• Mg/CSH showed superior degradability in SBF.
• Mg/CSH supported enhanced cBMSC attachment, proliferation, and osteogenic differentiation without significant cytotoxicity.
• In vivo implantation of Mg/CSH significantly increased new bone formation, bone mineral density, and bone area fraction.

Conclusions:

• The novel injectable Mg/CSH composite demonstrates significantly improved properties over traditional CSH.
• Mg/CSH shows excellent biocompatibility and osteoconductivity, promoting effective bone regeneration.
• This Mg/CSH composite holds significant promise as an injectable bone scaffold for bone repair and bone tissue engineering.