Synthesis and thermally-triggered self-assembly behaviors of a dumbbell-shaped polymer carrying β-cyclodextrin at branch points

Construction of β-cyclodextrin-based supramolecular hyperbranched polymers self-assemblies using AB2-type macromonomer and their application in the drug delivery field

Despite some efforts have been made in the research of supramolecular hyperbranched polymers (SHPs) self-assemblies, the study which has not been consideration to date is the influence of incoming stimuli-responsive polymer chain on their self-assembly property undergo outer stimuli. The introduction of stimuli-responsive segments which could maintain their hydrophilic property are expected to affect the self-assembly behaviour of SHPs and expand their further biomedical application. In this paper, AB₂-type macromolecular monomer, LA-(CD-PDMA)₂, which consisted one lithocholic acid (LA) and two β-cyclodextrin terminated poly(2-(dimethylamino)ethyl methacrylate) segments (CD-PDMA) was synthesized. LA-(CD-PDMA)₂ based SHP were obtained based on the host-guest inclusion interactions of CD/LA moietes and with PDMA as pH-responsive hydrophilic chains. As a control to study the influence of incoming PDMA chains, both LA-(CD-PDMA)₂ based SHPs-1 and LA-CD₂ based SHPs-2 self-assemblies were comparatively investiged through 2D ¹H NMR ROESY, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The results suggested that except for the higher drug loading efficiency LA-(CD-PDMA)₂ based SHPs-1 pocessing, the release rates of SHPs-1 increased notably at pH 5.0 than that of pH 7.4 due to the repulsion and stretch of protonated PDMA chains while the release rates of SHPs-2 showed no obvious difference. Finally, basic cell experiments demonstrated that the SHPs based self-assemblies can be internalized into cancer cells, indicating their potential application in the drug delivery field.

Functional materials generated by allying cyclodextrin-based supramolecular chemistry with living polymerization

Cyclodextrin molecules are cyclic oligosaccharides that display a unique structure including an inner side and two faces on their outer sides.

Host-Guest Binding-Site-Tunable Self-Assembly of Stimuli-Responsive Supramolecular Polymers

Despite the remarkable progress made in controllable self-assembly of stimuli-responsive supramolecular polymers (SSPs), a basic issue that has not been consideration to date is the essential binding site. The noncovalent binding sites, which connect the building blocks and endow supramolecular polymers with their ability to respond to stimuli, are expected to strongly affect the self-assembly of SSPs. Herein, the design and synthesis of a dual-stimuli thermo- and photoresponsive Y-shaped supramolecular polymer (SSP2) with two adjacent β-cyclodextrin/azobenzene (β-CD/Azo) binding sites, and another SSP (SSP1) with similar building blocks, but only one β-CD/Azo binding site as a control, are described. Upon gradually increasing the polymer solution temperature or irradiating with UV light, SSP2 self-assemblies with a higher binding-site distribution density; exhibits a flower-like morphology, smaller size, and more stable dynamic aggregation process; and greater controllability for drug-release behavior than those observed with SSP1 self-assemblies. The host-guest binding-site-tunable self-assembly was attributed to the positive cooperativity generated among adjacent binding sites on the surfaces of SSP2 self-assemblies. This work is beneficial for precisely controlling the structural parameters and controlled release function of SSP self-assemblies.

Morphology transitions of supramolecular hyperbranched polymers induced by double supramolecular driving forces

Morphology transitions of supramolecular hyperbranched polymers can be induced under the double actions of host–guest inclusion and hydrophilic–hydrophobic interactions.

Thermo-responsiveness and biocompatibility of star-shaped poly[2-(dimethylamino)ethyl methacrylate]-b-poly(sulfobetaine methacrylate) grafted on a β-cyclodextrin core

CDPDS star polymers exhibit tunable UCST behavior by varying arm density, solution pH and NaCl concentration, and can be good candidates used in biomedical relevant fields as well.

Cyclodextrin-tunable reversible self-assembly of a thermoresponsive Y-shaped polymer

The reversible self-assembly behavior of thermoresponsive γ-shaped polymer can be effectively tuned based on the inclusion complexation, intermolecular hydrogen bonding and steric hindrance of β-CD.

Nonionic cyclodextrin based binary system with upper and lower critical solution temperature transitions via supramolecular inclusion interaction

A nonionic binary aqueous interaction system consisting of β-cyclodextrin trimer (β-CD3) and naphthalene-terminated poly(ethylene glycol) (PEG-NP2), which has tunable upper critical solution temperature (UCST) behavior around room temperature and lower critical solution temperature (LCST) behavior at high temperature, was investigated. In the UCST transition, gel-like aggregates form because of supramolecular inclusion complexation between β-CD3 and PEG-NP2. During LCST transition, PEG-NP2 becomes insoluble in water, which results in its precipitation. The effects of concentration, stoichiometry of the two components, and electrolyte on UCST behavior are discussed. This study provides a new nonionic thermoresponsive material.

Facile synthesis of well-defined cyclodextrin-pendant polymer via ATRP for nanostructure fabrication

PEG-b-PCD block copolymer could be synthesized by ATRP of a new methacrylate–CD monomer, and self-assembled into advanced nanostructures with various guest molecules.

Nanoassemblies driven by cyclodextrin-based inclusion complexation

Nanoassemblies driven by cyclodextrin-based inclusion complexation as functional nanomaterials.