Synthesis of imidazolium-containing mono-methacrylates as polymerizable antibacterial agents for acrylic bone cements

With the aim to prepare antibacterial acrylic bone cements, a series of imidazolium-containg mono-methacrylates with N-alkyl chain length varied from 10 to 18 (MEIM-x) were synthesized as polymerizable antibacterial agents through a two-step reaction. The structures of the monomers were confirmed by ¹H NMR. Methyl methacrylate in the liquid compoent of cements was partially replaced by MEIM-x to prepare bone cements with 5wt% of MEIM-x. Properties of prepared cements like antibacterial activity, doughing time, curing parameters including maximum temperature (T_max) and setting time (t_set), flexual strength (FS) and modulus (FM), compressive strength (CS) and fluid uptake (FU) in Ringer's solution were investigated. Acrylic bone cement without any MEIM-x was used as control. Compared with the control cement, MEIM-x-containing cements had shorter doughing time, lower T_max, same or longer t_set, and higher FU. Though MEIM-x could endow cements with strong antibacterial activity, it could reduce mechanical properties of bone cements. Therefore, further study should be taken to optimize the content of MEIM-x in cement which could supply sufficient antibacterial activity and maintain mechanical performance.