Adhesion of N-methacryloyl-omega-amino acid primers to collagen analyzed by C-13 NMR

Previously, we reported that the strength of the interaction between N-meth acryloyl-omega -amino acid (NM omegaA) primers and dentinal collagen exhibi ted a strong correlation with the bond strength of the resin to etched dent in. To determine the pertinent functional groups of the amino acid residues in the dentinal collagen, to which the amide and/or the carboxylic acid gr oups of the NM omega As are adsorbed, we used C-13 NMR techniques-primarily through the observation of spin-lattice relaxation times, T-i-to investiga te the adsorption characteristics resulting from the interaction of NM omeg a As with a model oligopeptide for collagen, (PPG)(5). The addition of NM o mega As to a collagenous solution resulted in a decrease in the T-1 values of the carbonyl carbons attributed to the carboxylic acid of the C-terminal Gly and to the third amide of the N-terminal Pro residues in the (PPG)(5) molecule, thus reflecting the formation of hydrogen-bonded interactions.