Cytotoxicity assays of new artificial tears containing 2-methacryloyloxyethyl phosphorylcholine polymer for ocular surface cells.

Purpose: 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymer is a multifunctional agent with antiadhesive, antithrombogenetic, and strong hydrating properties. MPC polymer-containing eye drops are the first such ophthalmic product to be commercially available; they contain approximately 0.1% Lipidure-PMB (copolymer of MPC and butyl methacrylate; NOF Corporation, Tokyo, Japan). This study evaluated the cytotoxicity of this new product toward ocular surface cells.

Methods: SIRC (rabbit cornea), BCE C/D-1b (bovine cornea), RC-1 (rabbit cornea), and Chang (human conjunctiva) cell lines were tested in this study. Cell viability was measured using both the MTT assay and the neutral red test in cells treated for 10, 30, or 60 min with MPC-containing eye drops and 4 commercial ophthalmic solutions containing sodium hyaluronate (SH) at various doses (undiluted, twofold diluted, and tenfold diluted). Cell viability scores were calculated. Cell viability was analyzed using ANOVA and the Dunnett test.

Results: After treatment with the MPC eye drops, cell viability rates were maintained at over 80% irrespective of the cell lines, dilution rates, exposure times, and assays, and were similar to those of the clinically approved artificial tear products other than Hyalein 0.1%, although some significant differences were found.

Conclusions: The MPC eye drops were tolerable to ocular surface cells, and comparable to single doses of clinically approved drugs containing sodium hyaluronate.