Chemical modification of chitosan. Part 9: Reaction of N-carboxyethylchitosan methyl ester with diamines of acetal ending PAMAM dendrimers

N-carboxyethylchitosan methyl ester (degree of substitution (DS)=1.2 per repeating residue of chitosan), which was prepared from chitosan and methyl acrylate by the Michael reaction, was reacted with diamine and gave a water-soluble product. The DS value of the diamine moiety was 0.64–0.94. Acetal ending poly(amidoamine) (PAMAM) dendrimers were successfully attached to the ester and gave an N-carboxyethylchitosan–dendrimer hybrid without any crosslinking. The DS values of the hybrids were gradually decreased from 0.61 to 0.04 with the increasing generation of dendrimer.