Thermoresponsive poly(oligo ethylene glycol acrylates)

Hyperbranched poly(triazole) with thermal and metal ion dual stimuli-responsiveness

Hyperbranched poly(triazole) bearing oligo(ethylene glycol) terminal groups is dual stimuli-responsive to thermal conditions and metal ions and is capable for the selective absorption of Ag⁺ ion on tuning temperature.

Thermoregulated phase transfer catalysis in aqueous/organic biphasic system: facile and highly efficient ATRP catalyst separation and recycling in situ using typical alkyl halide as initiator

An important development of TRPTC-based ICAR ATRP for metal catalyst separation and recycling in an aqueous/organic biphasic system was achieved with alkyl halide as the initiator for the first time.

UCST behavior of polyampholytes based on stoichiometric RAFT copolymerization of cationic and anionic monomers

Polyampholytes with controlled equimolar ratio of charges were synthesized by reversible addition–fragmentation chain transfer (RAFT) copolymerization of cationic and anionic monomers and their UCST behavior is reported.

Thermoresponsive polymer coated gold nanoparticles: from MADIX/RAFT copolymerization of N-vinylpyrrolidone and N-vinylcaprolactam to salt and temperature induced nanoparticle aggregation

In the present contribution, we report the synthesis of thermoresponsive homo and statistical copolymers of N-vinylcaprolactam and N-vinylpyrrolidone and the corresponding responsive gold nanoparticles.

Biodegradable stimuli-responsive polypeptide materials prepared by ring opening polymerization

This tutorial review summarizes the most recent progress in stimuli-responsive polypeptides over the past decade.

Thermoresponsive polymeric temperature sensors with broad sensing regimes

Polymeric temperature sensors with a broad sensing regime in aqueous solution have been developed.

Polypeptoids with tunable cloud point temperatures synthesized from N-substituted glycine N-thiocarboxyanhydrides

Poly(sarcosine-r-N-butylglycine) random copolymers with various MWs and compositions are synthesized from NTA monomers, which exhibit tunable T_cps in aqueous solutions.

Synthesis and properties of tunable thermoresponsive aliphatic polycarbonate copolymers with oligo ethylene glycol containing thioether and/or sulphone groups

Tunable thermoresponsive aliphatic polycarbonates with oligo ethylene glycol containing thioether and/or sulphone groups.

Degradable ketal-based block copolymer nanoparticles for anticancer drug delivery: a systematic evaluation

Low solubility of potent (anticancer) drugs is a major driving force for the development of noncytotoxic, stimuli-responsive nanocarriers, including systems based on amphiphilic block copolymers. In this regard, we investigated the potential of block copolymers based on 2-hydroxyethyl acrylate (HEA) and the acid-sensitive ketal-containing monomer (2,2-dimethyl-1,3-dioxolane-4-yl)methyl acrylate (DMDMA) to form responsive drug nanocarriers. Block copolymers were successfully synthesized by sequential reversible addition-fragmentation chain transfer (RAFT) polymerization, in which we combined a hydrophilic poly(HEA)x block with a (responsive) hydrophobic poly(HEAm-co-DMDMAn)y copolymer block. The DMDMA content of the hydrophobic block was systematically varied to investigate the influence of polymer design on physicochemical properties and in vitro biological performance. We found that a DMDMA content higher than 11 mol % is required for self-assembly behavior in aqueous medium. All particles showed colloidal stability in PBS at 37 °C for at least 4 days, with sizes ranging from 23 to 338 nm, proportional to the block copolymer DMDMA content. Under acidic conditions, the nanoparticles decomposed into soluble unimers, of which the decomposition rate was inversely proportional to the block copolymer DMDMA content. Flow cytometry and confocal microscopy showed dose-dependent, active in vitro cellular uptake of the particles loaded with hydrophobic octadecyl rhodamine B chloride (R18). The block copolymers showed no intrinsic in vitro cytotoxicity, while loaded with paclitaxel (PTX), a significant decrease in cell viability was observed comparable or better than the two commercial PTX nanoformulations Abraxane and Genexol-PM at equal PTX dose. This systematic approach evaluated and showed the potential of these block copolymers as nanocarriers for hydrophobic drugs.

Poly(N-vinylcaprolactam): a thermoresponsive macromolecule with promising future in biomedical field

Poly(N-vinylcaprolactam) (PNVCL) is a thermoresponsive and biocompatible polymer that raises an increasing interest in the biomedical area, especially in drug delivery systems (DDS) that include micelles, hydrogels, and hybrid particles. The thermoresponsiveness of PNVCL, used alone or in combination with other stimuli- responsive polymers or particles (pH, magnetic field, or chemicals), is often key in the loading and/or release process in these DDS. The renewed focus on this polymer, which is known for decades, is to a large extent due to recent progress in synthetic strategies. Especially, the advent of efficient controlled radical polymerization (CRP) methods for NVCL monomer gives now access to unprecedented well-defined NVCL-based copolymers with unique properties. This Review article addresses up-to-date synthetic aspects, biological features, and biomedical applications of the latest NVCL-containing systems.

Synthesis of poly(poly(ethylene glycol) methacrylate)-polyisobutylene ABA block copolymers by the combination of quasiliving carbocationic and atom transfer radical polymerizations

Systematic investigations are carried out on the synthesis of a series of new, unique ABA-type triblock copolymers consisting of the hydrophobic and chemically inert polyisobutylene (PIB) inner and the hydrophilic comb-shaped poly(poly(ethylene glycol) methacrylate) (PPEGMA) polymacromonomer as an outer block. Telechelic PIB macroinitiators with narrow molecular weight distributions (MWD) are synthesized by quasiliving carbocationic polymerization of isobutylene with a bifunctional initiator followed by quantitative chain end derivatizations. Atom transfer radical polymerization (ATRP) of PEGMAs with various molecular weights is investigated by using these macroinitiators. It is found that CuBr is an inefficient ATRP catalyst, while CuCl leads to high, nearly complete conversions of the PEGMA macromonomers. Gel permeation chromatography (GPC) analyses reveal slow initiation of PEGMA at relatively high PIB/PEGMA ratios or with PEGMAs of higher molecular weights due to steric hindrance between the macroinitiator and macromonomer. The occurrence of slow initiation, and not permanent termination, is proven by highly efficient ATRP of a low-molecular-weight monomer, methyl methacrylate, with the block copolymers as macroinitiators. Successful synthesis of PPEGMA-PIB-PPEGMA ABA block copolymers is obtained by using either low-molecular-weight PEGMA or relatively low macroinitiator/macromonomer ratios. Differential scanning calorimetry (DSC) indicates phase separation and significant suppression of the crystallinity of the pendant poly(ethylene glycol) (PEG) chains in these new block copolymers.

Double thermoresponsive di- and triblock copolymers based on N-vinylcaprolactam and N-vinylpyrrolidone: synthesis and comparative study of solution behaviour

Controlled radical polymerization produces poly(N-vinylamide)s with thermally induced multistep assembly.