Stimuli-responsive and core cross-linked micelles developed by NiCCo-PISA of helical poly(aryl isocyanide)s

We report the synthesis of redox- and pH-sensitive block copolymer micelles that contain chiral cores composed of helical poly(aryl isocyanide)s. Pentafluorophenyl (PFP) ester-containing micelles synthesised via nickel-catalysed coordination polymerisation-induced self-assembly (NiCCo-PISA) of helical poly(aryl isocyanide) amphiphilic diblock copolymers are modified post-polymerisation with various diamines to introduce cross-links and/or achieve stimulus-sensitive nanostructures. The successful introduction of the diamines is confirmed by Fourier-transform infrared spectroscopy (FT-IR), while the stabilisation effect of the cross-linking is explored by dynamic light scattering (DLS). The retention of the helicity of the core-forming polymer block is verified by circular dichroism (CD) spectroscopy and the stimuli-responsiveness of the nanoparticles towards a reducing agent (l-glutathione, GSH) and pH is evaluated by following the change in the size of the nanoparticles by DLS. These stimuli-responsive nanoparticles could find use in applications such as drug delivery, nanosensors or biological imaging.

Synthesis of multiple stimuli-responsive degradable block copolymers via facile carbonyl imidazole-induced postpolymerization modification

A robust approach that centers on carbonyl imidazole chemistry was used to synthesize a triple-stimuli-responsive degradable block copolymer labeled with acetal, disulfide, and o-nitrobenzyl groups exhibiting acid, reduction, and light responses.

Self-Assembled Polymeric Materials: Design, Morphology, and Functional-Oriented Applications

This Review focuses on the current research advances of the synthesis of various amphiphilic block copolymers (ABCs), such as conventional ABCs and newly-presented polyprodrug amphiphiles (PPAs), and the development of corresponding self-assemblies in selective solvents driven by the intermolecular interactions, like noncovalent hydrophobic interactions, π-π interactions, and hydrogen bonds, between ABCs or preformed small polymeric nanoparticles. The design of these assemblies is systematically introduced, and the diverse examples concerning the unique assembly structures along with the fast development of their exclusive properties and various applications in different fields were discussed. Possible perspectives on the existential challenges and glorious future were elucidated finally. We hope this review will provide a convenient way for readers to motivate more evolutional innovative concepts and methods to design next generation of novel polymeric nanoassemblies, and fill the gap between material design and practical applications. This article is protected by copyright. All rights reserved.

Mercapto-responsive polymeric nano-carrier capable of releasing sulfur dioxide

This article reports platform to prepare polymeric nano-carriers capable of releasing SO₂ and hydrophobic payloads upon triggering by mercapto-containing species.

Construction of biodegradable core cross-linked nanoparticles from near infrared dyes encoded in polyprodrug amphiphiles and investigation of their synergistic anticancer activity

Amphiphilic polyprodrugs with reduction-responsive camptothecin prodrug and photothermal converted IR780 dyes was performed via core cross-linking protocol. The nanoparticles could be served as a nanocarrier and presented severe cytotoxicity to HeLa cells.

Strategy for optical data encryption and decryption using a D-A type stimuli-responsive AIE material

In this study, we report a new donor-acceptor (D-A) type stimuli-responsive material, (E)-4-(((9-ethyl-9H-carbazol-2-yl)methylene)amino)benzoic acid (C1), which possesses both aggregation-induced emission (AIE) and intramolecular charge transfer (ICT) natures. It glows green photoluminescence which changes into yellow color in response to mechanical stimuli, and fumigation in volatile organic compounds (VOCs) can switch the emission back to the initial state with high reversibility. In addition, the C1 film glows yellow-orange light, but turns into blue emission under continuous fumigation in ethyl acetate vapor. However the vapochromism behaves different when the C1 film is smeared: The emission of the smeared film is similar to the unsmeared but changes into cyan color after fumigation. The differences in vapochromism between smeared and unsmeared film can be easily distinguished by naked eyes. As revealed by SEM, the as-prepared film undergoes a morphology change from ill-shaped particles to microspheres in response to organic vapor, while the smeared film with scratched surface changes into dendritic patterns. According to the morphology study, the vapochromic luminescence can be ascribed to the physical adsorption of ethyl acetate vapor and the resulting change in the ICT process. In light of the unique vapochromism of C1, a new encryption-decryption technique for data recording was developed. Information can be recorded on the C1 film by mechanical writing and simultaneously concealed. It can be only accessed via fumigation in organic vapor, demonstrating a reliable steganography technology.

Nickel-Catalyzed Coordination Polymerization-Induced Self-Assembly of Helical Poly(aryl isocyanide)s

The interest in helix-containing nanostructures is currently growing as a consequence of their potential applications in areas such as nanomedicine, nanomaterial design, chiral recognition, and asymmetric catalysis. Herein, we present a facile and tunable one-pot methodology to achieve chiral nano-objects. The nickel-catalyzed coordination polymerization-induced self-assembly (NiCCo-PISA) of helical poly(aryl isocyanide) amphiphilic diblock copolymers was realized and allowed access to various nano-object morphologies (spheres, worm-like micelles, and polymersomes). The helicity of the core block was confirmed via circular dichroism (CD) spectroscopy for all morphologies, proving their chiral nature. Small-molecule uptake by the spherical nanoparticles was investigated by encapsulating Nile Red into the core of the spheres and subsequent transfer into aqueous media. The presence of a CD signal for the otherwise CD-inactive dye proved the chiral induction effect of the nano-objects' helical core. This demonstrates the potential of NiCCo-PISA to prepare nanoparticles for applications in nanomaterials, catalysis, and recognition.

Phenylboronic Acid-Dopamine Dynamic Covalent Bond Involved Dual-Responsive Polymeric Complex: Construction and Anticancer Investigation

In cancer treatment, prolonging the retention time of therapeutic agents in tumor tissues is a key point in enhancing the therapeutic efficacy. However, drug delivery by intravenous injection is always subjected to a "CAPIR" cascade, including circulation, accumulation, penetration, internalization, and release. Intratumoral administration has gradually emerged as an ideal alternative approach for nanomedicine because of its independence of blood constituents and minimal systemic toxicities. In this contribution, based on the dynamically reversible interaction between boronic acid (BA) and dopamine (DA), a thermo- and pH-responsive polymeric complex is rationally obtained by facile mixing of phenylboronic acid (PBA)- and tetraphenylethene (TPE)-modified poly(N-isopropylacrylamide)-b-poly(phenyl isocyanide)s block copolymers, PNIPAM-b-P(PBAPI-co-TPEPI), and tetra(ethylene glycol) methyl ether acrylate (OEGA)- and DA-containing hydrophilic P(DA-co-OEGA) copolymers. The resultant complex exhibited temperature- and pH-dependent size change as well as sustained nile red (NR) release profiles in a mimic tumor environment. Moreover, thanks to the opposite optical behavior of TPE and NR molecules, the complex could be served as a fluorescence ratiometric cell imaging agent, avoiding the interference of background fluorescence and improving correlated resolution. After encapsulation of camptothecin (anticancer drug), the efficient killing on HeLa cells was achieved in vitro, and the structural integrity of the complex endowed its extended retention time in tumor tissues. Considering these advantages, the reversible covalent interaction between PBA and diols can be used as an efficient driving force to form dynamic drug-delivery vectors, which are promising to be an effective nanoplatform for injectable medical treatments.

Chiral Self-Assembly of Nanoparticles Induced by Polymers Synthesized via Reversible Addition-Fragmentation Chain Transfer Polymerization

Chiral inorganic nanomaterials are of great interest because of their excellent optical properties. Most of the attention has been focused on the utilization of biomolecules or their derivatives as linkers or templates to control the chiral structure of assembled inorganic nanoparticles. Chiral polymers are promising synthetic materials that can be used to replace their biological counterparts. Here, by using poly(methacrylate hydroxyethyl-3-indole propionate) (PIPEMA) and poly(2-hydroxyethyl methacrylate) (PHEMA) synthesized via syndioselective reversible addition-fragmentation chain transfer polymerization, we successfully realized chiral self-assembly of gold nanorods with strong circular dichroism response in the vis-NIR region. Moreover, the intensity of the chiral signal of the assemblies can be regulated by the molecular weight of the polymers. Notably, although the monomers are achiral and no chiral reagents are involved in their synthesis, the main chains of PIPEMA and PHEMA exhibit a preferred-handed helical conformation, which is the origin of chirality of the nanorod assemblies. The preferred-handed helical conformation of polymers is attributed to their syndiotacticity and stabilized by the steric hindrance of the side groups. The addition of chiral carbon atoms at the side groups does not change the preferred-handedness of the polymer main chain, resulting in the assembled nanorod structures with the same chirality. This strategy provides inspiration for the rational design and synthesis of optically active functional synthetic polymers for the preparation of promising chiral nanomaterials.

Completely degradable backbone-type hydrogen peroxide responsive curcumin copolymer: synthesis and synergistic anticancer investigation

So far, several different kinds of polymer based drug delivery systems have been developed one after another.

Positively charged helical chain-modified stimuli-responsive nanoassembly capable of targeted drug delivery and photoacoustic imaging-guided chemo-photothermal synergistic therapy

Tumor targeted size-switchable CPT/IR780@H30-PCL-PPI(L−)/PEI(–COOH/FA) nanoassembly with a “pomegranate” construction was designed, which could efficiently expand the penetration depth and accelerate the cell internalization.

Photo-induced hydrogen-bonding complexes for drug periodic release

A convenient approach for periodic drug release was accomplished through photo-induced hydrogen-bonding complexation, and then by further disruption upon heating.