This work describes a new synthetic route to obtain fully oligosaccharides-based amphiphilic diblock copolymers, made from tamarind seeds xyloglucan. A mixture of well size-defined xyloglucooligosaccharides (XGO of 7, 8 and 9 carbohydrate units) were obtained from the cellulose-mediated enzymatic digestion of xyloglucanes. To perform the Huisgen click reaction the oligosaccharides were reducing end functionalized by azide and propargyl functions via microwave-catalyzed reductive amination. The hydrophobic block was obtained after peracetylation of alkyne-containing XGO. The amphiphilic co-oligomers were synthesized either from the mixture of xyloglucan oligosaccharides to give XGO-b-XGO,Ac, either from the monodisperse XGO of 7 carbohydrate units (DP7), obtained by a degalactosylation process involving another specific enzymatic hydrolysis (beta-galactosidase from Aspergillus Niger), to give DP7-b-DP7,Ac. The XGO-based diblocks were characterized according to the state-of-the-art in structural characterization (NMR, MS, FT-IR) and Soft Matter physico-chemistry (SLS, DLS, CMC, TEM) techniques. The removal of galactose units (DP7-b-DP7,Ac) conferred an increase in the critical micellar concentration value compared to XGO-b-XGO,Ac, which were determined by fluorescence spectroscopy. The size diameter of the micelles were carried out by dynamic light scattering (DLS) and confirmed by transmission electron microscopy (TEM). Spherical micelles with an average size of 25 nm for XGO-b-XGO,Ac and 6 nm DP7-b-DP7,Ac nanoparticles were observed by TEM. The partial enzymatic digestion of the shell constituting XGO-b-XGO,Ac micelles in water led to formation of DP7-b-XGO,Ac micelles with a lowest polydispersity and a decrease in the average size diameter by 50 %, as determined by DLS. XGO-b-XGO,Ac was tested as a nonionic block copolymer surfactant to stabilize zein and gliadin nanoparticles, which come from gluten of wheat and maize and were prepared by the method of desolvation. Its stabilizing properties were compared to Pluronic F68 surfactant belonging to poloxamers' family. The results suggest the suitability of the XGO-based diblock to stabilize zein aggregates, resulting in stable, monodisperse and spherical nanoparticles. Finally, this work proposed a system consisting in potential nanocarriers prepared from vegetable proteins stabilized by biosourced oligosaccharide surfactants.
