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

Abstract

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(ε-caprolactone) (PCL; as the B block), i.e., linear AB-type diblock copolymers with varied PCL molecular weights (MH-b-PCL (2.5k,3.3k,5k,10k) ), AB y -type (y = 2, MH-b-, which had been precisely synthesized via the combination of the living ringopening 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 (R h ) of 17−43 nm. MH-b-(PCL 5k ) 2 and MH-b-(PCL 3.3k ) 3 , which have an N PCL comparable to MH-b-PCL 10k , were found to form large compound micelles with relatively large radii (R h of 49 and 56 nm, respectively). On the other hand, (MH) 2 -b-(PCL 5k ) 2 , (MH) 2 -b-PCL 10k , and (MH) 3 -b-PCL 10k predominantly formed the regular core−shell micellar nanoparticles (R h = 29−39 nm) with a size smaller than that of MH-b-PCL 10k (R h = 43 nm).

Mechanistic Studies of Redox-Switchable Copolymerization of Lactide and Cyclohexene Oxide by a Zirconium Complex

“…Altering the length, number of blocks, or microstructure of the block copolymer provides a number of ways to tune the material's properties. [5][6][7] Switchable catalysis has emerged over the past few years as an increasingly viable method toward achieving controlled block copolymer synthesis. [25][26][27][28][29][30][31][32][33] Redox switches for polymerization reactions are particularly useful and have shown good applicability.…”

Click chemistry strategies for the accelerated synthesis of functional macromolecules

“…Cores with various numbers of azide and hydroxyl groups were prepared ((N 3 ) m –(OH) n , m and n = 1, 2, 3) and subjected to ROP to grow PCL arms followed by CuAAC conjugation of alkyne functionalized MH arms (Figure 47). 723 Similarly, Yagci prepared ABC miktoarm star copolymers using a trifunctional core containing azido, allyl, and hydroxyl groups. The initial chain was generated by ROP, followed by coupling of two more arms to the core via CuAAC and thiol‐ene 349 …”

Sequence and Architectural Control in Glycopolymer Synthesis

“…Apart from varying the block lengths, Satoh et al prepared a range of miktoarm block copolymers to obtain different glycopolymer morphologies . A series of different miktoarm polymers was prepared in which the amount of arms per block was changed; this altered the packing parameter, resulting in a change in micelle size.…”