Self-Assembly of Maltoheptaose-block-polycaprolactone Copolymers: Carbohydrate-Decorated Nanoparticles with Tunable Morphology and Size in Aqueous Media

This paper describes the systematic investigation into the aqueous self-assembly of a series of block copolymers (BCPs) consisting of maltoheptaose (MH; as the A block) and poly(e-caprolactone) (PCL; as the B block), i.e., linear AB-type diblock copolymers with varied PCL molecular weights (MH-b-PC1-(2.5(k,3.3k,5k10k))), AB(y)-type = 2, MH-b(PCL5k) 2; y = 3, MH-b-(PCL3.3k)(3)), A(2)B(2)-type ((MH)(2)-b(PCL(5)k)(2)), and AxB-type miktoarm star polymers (x = 2, (MH)2-b-PCL10k; x = 3, (MH)(3)-b-PCLiok), which had been precisely synthesized via the combination of the living ring opening polymerization and click reaction. Under similar conditions, the nanoprecipitation method was employed to self -assemble them in an aqueous medium. Imaging and dynamic light scattering techniques indicated the successful formation of the carbohydrate -decorated nanoparticles via self -assembly. The MH-b-PCLs formed regular core shell micellar nanoparticles with the hydrodynamic "radius (Rh) of 17-43 nm. MH-b-(PCL5k)2 and MH-b-(PCL3.3k)(3), which have an NPCL comparable to MH-b-PCLiok, were found to form large compound micelles with relatively large radii (Rh of 49 and 56 nm, respectively). On the other hand, (MH),-b-(PCL5k),, (MH),-b-PCLiok, and (MH)3-bPCLiok predominantly formed the regular core shell micellar nanoparticles (Rh = 29-39 nm) with a size smaller than that of MH-b-PCLiok (Rh = 43 nm).