Synthesis of amphiphilic A3B mikto-arm copolymer from a sugar core : combination of hydrophobic PCL and hydrophilici glycopolymers for biocompatible nanovector preparation

Amphiphilic A3B mikto-arm copolymers have been synthesized using a t-butyl-diphenyl silyl-based methylglucoside derivative. The latter has been first used as initiator for the polymerization of e-caprolactone leading to three-arm star-shaped structures followed by several postpolymerization steps to obtain star-shaped poly(e-caprolactone) macroinitiator. Atom transfer radical polymerization (ATRP) of diisopropylidene galactose methacrylate in THF at 60 °C using CuBr ligated with 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) as catalytic complex allowed the formation of A3B mikto-arm copolymers with different compositions and molecular weights. Selective deprotection of sugar protecting groups finally generated amphiphilic mikto-arm copolymers. The molecular characterization of those copolymers was performed by 1H NMR spectroscopy and gel permeation chromatography (GPC) analysis. The self-assembly of the copolymers into micellar aggregates and the related critical micellization concentration (CMC) in aqueous media were determined by dynamic light scattering (DLS) and UV-visible spectroscopy, respectively