Study on synthesis of glycopeptide-based triblock copolymers and their aggregation behavior in water

This paper describes a preliminary study on the synthesis of glycopeptide-based triblock copolymers and their aggregate behavior in water. Initially, a polypeptide-based triblock copolymer, poly(L-lysine)-b- poly(tetrahydrofuran)-b-poly(L-lysine) (PLL₃₀-b-PTHF-b-PLL ₃₀), was synthesized by the ring-opening polymerization of ε-benzyloxycarbonyl-L-lysine N-carboxyanhydride using amine-terminated poly(tetrahydrofuran) as a macroinitiator in the fixed feed ratio, followed by the removal of the protecting group. The resulting copolymer then reacted with a varying amount of D-gluconolactone in the presence of dipropylethylamine to give the corresponding glycopeptide-based copolymers with high yields. This kind of amphiphilic sugar-containing triblock copolymer can self-assemble into nano-sized aggregates in water. The critical aggregation concentration (CAC) was determined in the range of around 10^-6 M by fluorescence measurement. The spherical morphologies in 100-150 nm scale were also evidenced by transmission electron microscopy (TEM) measurements. They show potential as carriers for drug controlled delivery and templates for biomimetic mineralization.