Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) with a β-cyclodextrin (β-CD) at the chain end was synthesized via atom transfer radical polymerization (ATRP); poly(ε-caprolactone) (PCL) with a −CC– segment and an adamantane (Ada) group at two ends, respectively, was prepared through ring-opening polymerization (ROP), and poly(N-isopropylacrylamide) (PNIPAM) with a −S–C(S)–S– segment, which can be converted into a thiol group, was yielded by reversible addition–fragmentation chain transfer polymerization (RAFT). A supramolecular triblock stimuli-responsive copolymer PNIPAM-b-PCL-b-PDMAEMA having good biocompatibility with PNIPAM and PDMAEMA hydrophilic segments and PCL hydrophobic segment was constructed by thiol–ene Michael addition and host–guest interaction. The triblock copolymer could self-assemble into vesicles and respond to carbon dioxide (CO2) gas and temperature reversibly. Under the stimulation of CO2, the vesicular assemblies swelled obviously; while raising the temperature from 25 to 40 °C, the assemblies displayed a conversion between vesicles and spherical micelles.

A dynamic cross-linked supramolecular network of poly(glycidyl methacrylate)s derivative chains was constructed on mesoporous silica nanoparticles via disulfide bond and ion-dipole interactions between cucurbit[7]urils and protonated diamines in the polymer chains. This kind of multifunctional organic-inorganic hybrid material with pH- and glutathione- (GSH-) stimuli responsiveness can be applied to anticancer drug delivery and controlled release. Good release performance toward doxorubicin hydrochloride (DOX) was achieved under the simulative tumor intracellular environment (pH = 5.0, CGSH = 2-10 mM). Significantly, the release amount of DOX increased upon lowering the solution pH value and increasing the concentration of GSH, as demonstrated by a series of controlled release experiments. Furthermore, the DOX-loaded hybrid nanomaterials displayed apparent cell-growth inhibition effects to cancer cell lines, as evidenced by MTT assay and confocal laser scanning microscopy.

Nucleated self-assembly in selective solvents of core-crystalline block copolymers (BCPs) is a special case of living supramolecular polymerization, leading to rodlike micelles of controlled and uniform length. For the crystallization-driven self-assembly of PFS-containing BCPs (PFS = polyferrocenyldimethylsilane), the formation of block comicelles by sequential addition of different BCPs is well-established. But there are only a few examples of living copolymerization, the simultaneous addition of pairs of BCPs with different corona-forming chains. At present, relatively little is known about the competitive kinetics of different BCPs crystallizing on a common seed. Here we report a systematic study of the competitive seeded growth kinetics of pairs of linear PFS-containing BCPs and show that one can manipulate the kinetics to control the morphology of the comicelles. We found that the seeded-growth kinetics of the individual BCP unimer dominates the coassembly behavior and thus the morphology of the corona. Patchy comicelles with microphase-segregated corona chains are formed when the epitaxial growth rates of the two different BCPs on the common seed are similar. In contrast, factors that lead to dissimilar growth rates (long corona-forming blocks or introduction of charges on corona-forming chains) promote large-scale separation of the corona blocks, leading to block comicelles. Because the termini of the comicelles remain living, they can further direct the growth of unimers, resulting in hierarchical block comicelles with patchy blocks and single-component (homo) blocks. Furthermore, the patchy comicelles can be loaded with either gold or platinum nanoparticles, generating organic-inorganic hybrid materials with potential application in catalysis.

There is a broad interest in elongated colloids as drug delivery vehicles, and current research aims to address how their length and aspect ratio affect interactions with cells. Block copolymer (BCP) micelles offer the opportunity to vary micelle length while maintaining cross-sectional width with corona chains that maintain a common surface chemistry across these structures. However, most elongated BCP micelles used in cell studies are characterized by a very broad length distribution. Here, we describe the synthesis and self-assembly properties of a diblock copolymer with a polyferrocenylsilane core-forming block and a corona block consisting of a statistical polymer of (aminopropyl)­methacrylamide and oligo­(ethylene glycol methacrylate) (M = 500) (PFS27-b-PAPMA3-stat-OEGMA48). Self-assembly in water gave a mixture of structures including rodlike micelles. In alcohols, different types of structures were obtained depending on the alcohol employed (butanol, 2-propanol, ethanol, and methanol). In ethanol, the polymer formed long micelles of uniform width by crystallization-driven self-assembly. Following sonication, a series of rodlike micelles with different lengths (80 to 2000 nm) and narrow length distributions (L w/L n < 1.10) were generated by seeded growth. These micelles could be transferred to aqueous media and maintained colloidally stable in PBS (phosphate-buffered saline) buffer for more than three months. In these micelles, the POEGMA brush provides a “stealth” coating to minimize the interaction with proteins and cells, and the APMA groups provide functionality for attachment of drugs or metal chelators for potential therapeutic applications. Studies in two human breast cancer cell lines (MDA-MB-231 and MDA-MB-436) show no signs of toxicity for micelle concentrations up to 0.1 mg·mL–1. We also show that metal chelators can be covalently attached to the amino groups in the corona and labeled with heavy metals, opening the door to future experiments with radionuclides.