Intrinsically Radiopaque, Iodine-Containing Bone Cement (2014)

Undergraduates: Daniel Liauw, Anne Jackson

Faculty Advisor: Valerie Ashby
Department: Chemistry

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Most acrylic bone cement formulations used in total joint replacements utilize inorganic contrast agents to achieve radiopacity and monitor healing. The incompatibility between polymeric and inorganic phases detrimentally affects mechanical, physical, and thermal properties of the bone cements. To rectify these drawbacks, an inherently radiopaque poly(methyl methacrylate)-based polymer was developed. To achieve this, an iodine-containing monomer, 3-iodi-2,2-bis(iodomethyl) propyl methacrylate (IIPMA) was synthesized and copolymerized with methyl methacrylate (MMA). Suspension polymerization was employed to synthesize beads of the iodine-containing copolymer, specifically block copolymers, that are of easily tunable molecular weights (from 100,000 to 500,000 g/mol) and easily scalable iodine content (7% to 20 wt. % iodine). The copolymerized microspheres had radii of 40-60 μm and a particle PDI less than 0.1, allowing them to be directly utilized as the powder portion of the bone cement. Tensile strength of IIPMA-based bone cement was determined to be appreciably improved. Continued characterization of bone cement will include further determination of mechanical properties, cytotoxicity, and radiopacity.