Development of new bone cement utilizing low toxicity monomers

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Polymer Chemistry

Background:

• Acrylic bone cement, based on methyl methacrylate (MMA), is widely used in orthopedics.
• Adverse effects associated with conventional MMA-based bone cement necessitate the development of safer alternatives.

Purpose of the Study:

• To investigate the development of a novel bone cement utilizing methacrylates with lower toxicity than MMA.
• To evaluate the safety and performance characteristics of the new cement, termed EHMA cement.

Main Methods:

• Determined LD50 values of candidate monomers, including 2-Ethylhexyl methacrylate (EHMA) and trimethylolpropane trimethacrylate (TMP), in rat femurs.
• Developed a new bone cement (EHMA cement) using EHMA and trimethylolpropane trimethacrylate (TMP) as liquid components and a copolymer of EHMA and cyclohexyl methacrylate as the powder component.
• Measured the temperature rise during polymerization and the compression strength of the developed EHMA cement.

Main Results:

• EHMA (187 mg/kg) and TMP (380 mg/kg) demonstrated higher LD50 values than MMA (108 mg/kg), indicating lower toxicity.
• EHMA cement exhibited a significantly lower temperature rise during polymerization (9°C-13°C) compared to conventional cement.
• The compression strength of EHMA cement was 57 MPa (without TMP) and 67 MPa (with 15 wt% TMP), which was slightly inferior to conventional cement.

Conclusions:

• The newly developed EHMA bone cement offers reduced toxicity and lower exothermic reaction during polymerization.
• While compression strength is slightly lower than conventional cement, EHMA cement presents a promising, safer alternative for orthopedic applications.