Effect of Simplex liquid methyl methacrylate monomer on cells.

The effect of methyl methacrylate monomer used for polymerization of surgical bone cement on phagocytosis, blood cells, tissue cells in culture, and bacteria was investigated. A concentration of 0.5% monomer reduced the ability of macrophages in vitro to phagocytize cultures of Staphylococcus epidermidis effectively. In vivo, 0.03 ml injected into mice also reduced the capacity of peritoneal macrophages to phagocytize bacteria. Extent of cellular damage to blood cells varied with concentration of monomer used and time of contact but, in general 0.5% was sufficient to alter morphology and viability of blood cells and tissue cells in culture. Polymorphonuclear neutrophils sustained more damage than other types of blood cells. Only minor alterations were detected from cooled, polymerized cement. These studies support the concept that the monomer, as well as mechanical and thermal factors, may be responsible for some of the tissue changes seen at the site of implant of bone cement following total joint arthroplastic surgery.