Cytotoxicity of methyl methacrylate (MMA) and related compounds and their interaction with dipalmitoylphosphatidylcholine (DPPC) liposomes as a modelfor biomembranes

OBJECTIVE: To clarify the potential mechanism of action of methyl methacryl ate (MMA) and related compounds to membranes of living cells, compared with their interaction with dipalmitoylphosphatidylcholine (DPPC) liposomes as a model for biological membranes. MATERIALS AND METHODS: For (meth)acrylates, MMA, ethyl acrylate(EA), n-buty l acrylate (BA) and n-butyl methacrylate (BMA) and for living cells, primar y human gingival fibroblast (HGF), human submandibular gland adenocarcinoma cell line (HSG) and human erythrocytes were used. The physicochemical chan ges in DPPC liposomes induced by (meth)acrylates were studied using differe ntial scanning calorimetry (DSC) and nuclear magnetic resonance spectroscop y (NMR), RESULTS: Cytotoxicity decreased as follows: BA>BMA>EA>MMA. Changes in phase transition properties (temperature T-m, enthalpy Delta H and Height/Half-H eight Width (H/HHW) of DSC peak were decreased as follows: BA>EA>MMA, BMA e nhanced H/HHW and increased T-m slightly. NMR-shielding effect decreased as follows: BMA>MMA>BA,EA. CONCLUSION: BA and BMA exhibited large cytotoxicity and high DPPC-interacti on due to their lipophilicity, compared to EA or MMA, MMA showed little cyt otoxicity and small changes in DPPC liposomes, whereas BA showed large cyto toxicity and large changes in the liposomes characterized by the membrane d isturbance, Haemolytic activity and cytotoxicity of acrylates were higher t han those of methacrylates. The physico-chemical properties (Log P or Q(sig ma)) of (meth) acrylates affect the lipid bilayer in biological membranes.