Hemolytic activity of a dental adhesive monomer (N-methacryloyloxy-5-aminosalicylic acid, MASA) and its interaction with phospholipid liposomes as studied by NMR and DSC.

N-methacryloyloxy-5-aminosalicylic acid (MASA) has recently been used as an adhesive primer in restorative resin systems. To monitor the biological activity of MASA, we studied changes in NMR-chemical shifts (delta H) and the differential scanning calorimetry (DSC) phase transition temperature (Tm) of dipalmitoylphosphatidylcholine (DPPC)/MASA liposomes with or without the presence of albumin and collagen. The delta H and the Tm did not alter significantly and the interaction of MASA with DPPC was found to be small. Hemolytic activity of MASA was markedly smaller than that of the phosphate monomer (MDP) in bonding agents widely used. These findings suggest that using a MASA primer in resin systems has an acceptable biocompatibility for dentin-pulp, involving its adsorption and adhesion to hard tooth tissues.