Changes in NMR Chemical Shifts of Methacrylates Induced by their Interactions with the Phospholipid and the Phospholipid/Cholesterol Liposome System

Abstract

The interaction of methyl methacrylate (MMA), ethylene dimethacrylate (EDMA) and triethyleneglycol dimethacrylate (TEGDMA), which are widely used in dentistry, with the dipalmitoyl phosphatidylcholine (DPPC) and the DPPC/cholesterol (CS) liposome system was studied by ¹H and ¹³C nuclear magnetic resonance spectroscopy (NMR). EDMA and TEGDMA have a larger interaction with the DPPC liposome system compared to MMA, resulting in changes in chemical shifts. The ¹³C chemical shift differences of C=C-C-O were larger than those of other carbon portions in methacrylate, indicating that double bonds interact predominantly with DPPC liposomes due to the hydrophobicity of methacrylates. At 37°C, ¹H signals from TEGDMA appeared in the DPPC/CS/TEGDMA liposome system, while signals due to H₂C=C-C-OCH₂CH₂ did not appear in the DPPC/TEGDMA liposome system.