Two-Compartment Micellar Assemblies Obtained via Aqueous Self-Organization of Synthetic Polymer Building Blocks

Abstract

We synthesized a symmetric linear ABCBA pentablock copolymer consisting of poly(ethylene oxide), poly(gamma-benzyl l-glutamate), and a poly(perfluoro ether) (fluorolink). The different blocks are highly immiscible with each other and form two-compartment micelles of mainly cylindrical shape in aqueous solution with lengths in the range of 100 to 200 nm and diameters of about 24 nm. The poly(perfluoro ether) (C blocks) forms the liquidlike center of the micelles (d = 6 nm). This is surrounded by a first shell of ca. 2 nm thickness consisting of beta-sheets of poly(gamma-benzyl l-glutamate) (B blocks) and a second 7 nm shell of poly(ethylene oxide) (A blocks). The A blocks provide water solubility, and the B and C blocks form separated hydrophobic compartments. This work is a contribution to the development of multicompartment micelles devoted to mimic transport proteins such as serum albumins in long-term development.

Understanding Multicompartment Micelles Using Dissipative Particle Dynamics Simulation

“…Thünemann and co-workers [24] observed cylindrical multicompartment micelles formed from ABC block copolymers consisting of hydrophilic poly(N-acylethyleneimine) endcapped with a hydrophobic fluorocarbon and a hydrocarbon block. They [25] also found that two compartment micellar solutions containing both spherical and cylindrical micelles could be formed from symmetric linear ABCBA pentablock copolymers consisting of poly(ethylene oxide), poly(g-benzyl L-glutamate) and poly(perfluoro ether)(fluorolink). Some typical morphologies observed are shown in Figure 1.…”

“…[15][16][17][18][19][20] At the moment, most work has focused on the preparation and characterization of new multicompartment micelles, [21][22][23][24][25] and an initial effort on the storage of two agents in a multicompartment micelle has recently been made. [26] Due to their structural complexity, it is difficult to assess the structure of the core of a multicompartment micelle rigorously, or indeed to visualize the evolution process of a multicompartment micelle directly by experiment.…”

“…[47] The former mimics the star triblock copolymers synthesized by Lodge and co-workers, [21] while the latter mimics the symmetric linear ABCBA pentablock copolymer synthesized by Thünemann and co-workers. [25] Lodge and co-workers [21] synthesized star triblock copolymers consisting of poly(ethylene oxide) (hydrophilic, denoted by O) blocks, poly(ethylethylene) (lipophilic, denoted by E) blocks and poly(perfluoropropylene oxide) (hydrophobic and lipophobic, denoted by F) blocks. The three blocks (E, F and O) are extremely incompatible, and F is more hydrophobic than E. Moreover, the O-F interfacial tension is greater than that of O-E and E-F. [21,48] We used A, B and C to represent the O, E and F blocks respectively, and obeyed the order of strength of the interactions in the choice of the DPD parameters required in the simulations.…”

“…[21] Various sets of DPD parameters were examined, and the set shown in Table 1 enabled the four constructed copolymers to reproduce the morphologies of the multicompartment micelles observed for the four real copolymers in water simultaneously. [46] Thünemann and co-workers [25] synthesized a symmetric linear ABCBA pentablock copolymer consisting of poly(ethylene oxide) (A block), poly(g-benzyl L-glutamate) (B block) and poly(perfluoro ether) (C block), and studied the formation of two compartment micelles of the copolymers in water. The A blocks are hydrophilic and the B and C blocks are hydrophobic, and the different blocks are highly immiscible with each other.…”

Multicompartment Micelles From π‐Shaped ABC Block Copolymers

“…Laschewsky et al 10 explored "spheres on spheres" multicompartment micelles formed from linear ABC block copolymers. Thünemann et al, 12 on the other hand, observed two-compartment cylindrical micelles formed from ABCBA block copolymers in dilute aqueous solutions.…”