Multicompartment Micelles from Polyester-Containing ABC Miktoarm Star Terpolymers

Abstract

Well-defined μ-[poly(ethylethylene)][poly(ethylene oxide)][poly(γ-methyl-ε-caprolactone)] (μ-EOC) miktoarm star terpolymers were prepared by a combination of two successive living anionic polymerizations and one controlled ring-opening polymerization (ROP). A mid-hydroxyl-functionalized poly(ethylethylene)-block-poly(ethylene oxide) (PEE−PEO) diblock copolymer served as a macroinitiator for the aluminum-mediated ROP of γ-methyl-ε-caprolactone (MCL), leading to a family of μ-EOC triblock copolymers having monomodal molecular weight distributions and controlled PMCL weight fractions. Micelle structures formed in water from μ-EOC containing various lengths of PMCL were examined by cryogenic transmission electron microscopy (cryo-TEM) and dynamic light scattering. Increasing the fraction of hydrophobic PMCL resulted in a transition from spherical to wormlike to approximately spherical micelles. Although the multicompartment cores of the μ-EOC micelles could not be directly resolved by cryo-TEM, small-angle X-ray scattering analysis of a representative PEE−PMCL diblock copolymer showed clear microphase separation, strongly suggesting the existence of multicompartment cores in the μ-EOC micelles. We speculate that the transition of μ-EOC micelles from worms to spheres can be attributed to the connection of the three immiscible blocks at one junction and documented micellar transitions in analogous PMCL−PEO diblock micelles.

Design Advances in Particulate Systems for Biomedical Applications

“…Playing with the proportions between the polymers, the shape of such compartmentalized particles was also controlled. [ 239 ] A few examples of multicompartmentalized micelles derived from the conjugation of PEE, PEO and poly(γ-methyl-ε-caprolactone) are depicted in Figure 22 . The ability of micelles to be loaded with two different molecules was proved by multicompartmented structures formed by selfassembly of mikto-arm star block copolymers.…”

Highly fluorinated amphiphilic molecules and self-assemblies with biomedical potential

“…Selective incorporation of FC molecules was demonstrated. Further multicompartmented systems have been obtained by self-assembly in water of linear [47] or star-shaped [48,49] triblock copolymers bearing a highly fluorinated arm, a polystyrene arm and a polymorpholinium or poly(ethylene oxide) arm. Self-assembly of linear triblocks having a poly(pentafluorophenyl 4-vinylbenzyl ether) block led to essentially spherical multicompartment micelles [47], while (F-octyl)ethyl-terminated poly(N-acylethylene imine) triblock compounds self-assembled into multicompartmented cylindrical micelles [50].…”

Water-Soluble Stimuli Responsive Star-Shaped Segmented Macromolecules

“…A number of well-defined poly(ethylethylene)-[poly(ethylene oxide)]-poly(γ-methyl-ε-caprolactone) (μ-EOC) miktoarm star terpolymers, were prepared and their dispersion in water was studied using cryoTEM and DLS [50]. The structure of the formed micelles was affected by the length of the PMCL arm.…”