Amphiphilic Polymer Research Articles

Investigation of the Interaction of Ionic Surfactants with Epoxy-Based Hydrogels by SANS.

We investigated the effect of two ionic surfactants on the composition and structure of hydrogels obtained by swelling an epoxy amphiphilic polymer network (APN) using a combination of gravimetry and small-angle neutron scattering (SANS). Stoichiometric epoxy APN was synthesized by the reaction of diamino and diepoxy-terminated polypropylene (POP) and polyoxyethylene (POE). Sub- and supercritical solutions of surfactants with either cationic (myristyltrimethylammonium bromide (C14TAB)) or anionic (sodium dodecyl sulfate (SDS)) headgroups in heavy water were used in the preparation of the hydrogels. At supercritical concentrations, SDS exhibited a much stronger effect on the composition and structure of the hydrogels than C14TAB. The details of the hydrogel structure were deduced by general analysis and fitting of the experimental SANS profiles to two model scattering functions exploiting the Percus-Yevick hard-sphere (HS) model and rescaled mean spherical approximation (RMSA), respectively. In the former model, valid for the hydrogels prepared in low concentrated surfactant solutions, spherical domains of average radius of ca. 39-45 Å from a highly swollen network dispersed in a matrix of a poorly swollen network mixed with the bound alkyl surfactant tails were revealed. In the latter model, hydrogels prepared in surfactant solutions of sufficiently high concentrations consist of surfactant micelles dispersed in a matrix of a highly swollen network. The average radii of the C14TAB and SDS micelles formed in the hydrogels were ca. 28 and 17 Å, respectively. The strong binding of surfactant tails with POP chains and dragging of large amounts of highly mobile counterions inside the hydrogels were responsible for the effects observed. This study provides important information about the surfactant organization inside polymer hydrogels, which is important for their applications.

Organic Salt-Doped Polymer Alloy: A New Prototype Hole Transporter for High-Photovoltaic-Performance Perovskite Solar Cells.

Hole-transporting layer (HTL) is one of the key components in a regular perovskite solar cell (r-PSC), which has the function of extracting the photon-excited holes from the absorber and then transporting them to the electrode. The most commonly used HTL in r-PSC is LiTFSI and tBP-doped spiro-OMeTAD. The inevitable instability induced by a deliquescent inorganic salt (LiTFSI), the migration of small lithium ions, and the necessary oxidation process in air hinder the commercialization of this technology. In this paper, a new undoped D-A copolymer (P15) is used as a hole-transporting material (HTM) for r-PSC but with moderate photovoltaic performance. Therefore, an organic salt, DPI-TPFB, having a big organic cation and a hydrophobic anion, was used as a dopant to increase the conductivity/hole mobility of P15 while avoiding the instability caused by lithium salt and moisture. Furthermore, an amphiphilic polymer, PDTON (with hole- transporting and perovskite-passivation ability), was added to P15 to form a polymer alloy, (P15 + PDTON), to further enhance the crystallinity and, therefore, the conductivity/hole mobility of P15 via space-confined interaction. As a result, r-PSCs based on DPI-TPFB-doped (P15 + PDTON) HTLs exhibit the highest power conversion efficiency (PCE) of 18.8%, which is higher than those of the cells based on DPI-TPFB-doped P15 (15.08%), DPI-TPFB-doped PDTON (7.37%), and undoped (P15 + PDTON) (15.66%) HTLs. Cells based on DPI-TPFB-doped (P15 + PDTON) HTL also have much better long-term stability than those using LiTFSI and tBP-doped spiro-OMeTAD as an HTL. The studies show that a polymer-compatible organic salt, DPI-TPFB, can be used as a stable dopant to increase the hole mobility of polymeric HTL without sacrificing the stability of the resulting cells, and mixing two ordinary photovoltaic performance polymeric HTLs (such as P15 and PDTON) can form a high- photovoltaic-performance polymer alloy (P15 + PDTON) HTL. Therefore, organic salt-doped polymer alloy can be regarded as a new prototype hole transporter for high-photovoltaic- performance PSCs.

Advanced nanomicelles for targeted glioblastoma multiforme therapy.

Glioblastoma multiforme (GBM) is the most aggressive and malignant primary brain tumor, classified as grade IV by the WHO. Despite standard treatments like surgical resection, radiotherapy and chemotherapy (i.e. temozolomide), GBM's prognosis remains poor due to its heterogeneity, recurrence and the impermeability of the blood-brain barrier (BBB). The exact cause of GBM is unclear with potential factors including genetic predisposition and ionizing radiation. Innovative approaches such as nanomicelles-nanoscale, self-assembled structures made from lipids and amphiphilic polymers show promise for GBM therapy. These nanocarriers enhance drug solubility and stability, enabling targeted delivery of therapeutic agents across the BBB. This review explores the synthesis strategies, characterization and applications of nanomicelles in GBM treatment. Nanomicelles improve the delivery of both hydrophobic and hydrophilic drugs and provide non-invasive delivery options. By offering site-specific targeting, biocompatibility, and stability, nanomicelles can potentially overcome the limitations of current GBM therapies. This review highlights recent advancements in the use of nanomicelles for delivering therapeutic agents and nucleic acids addressing the critical need for advanced treatments to improve GBM patient outcomes.

Investigation of Amphiphilic PDMS-Hyperbranched Polyglycerol Copolymers to Tune the Fouling-Release Properties in a Moisture Curable Coating System.

Hyperbranched polyglycerol (HBPG) has been proven to be effective as a hydrophilic material when incorporated into amphiphilic copolymers, enhancing fouling-release properties. These amphiphilic polymers not only increase the effectiveness of coatings across a wide range of organisms but also impart antifouling characteristics without resorting to toxic chemicals. HBPGs exhibit high resistance to proteins and lead to the effective removal of marine organisms under low impact pressures. To enhance the effectiveness of HBPGs and facilitate polymer stratification onto the coating surface, copolymers with polydimethylsiloxane (PDMS) were synthesized through a ring-opening multibranching polymerization reaction. These amphiphilic polymers, with varying molecular weights of the PDMS block and different degrees of branching in the HBPG blocks, were incorporated into a urea-siloxane moisture-cure coating system at a concentration of 5 wt %. This study aimed to identify the optimal molecular weight of PDMS and the degree of branching in HBPG that provides the most improved fouling-release (FR) properties to the base coating. The amphiphilic copolymers underwent thorough characterization using Fourier transform infrared (FTIR), NMR, and surface tension measurements. Coatings were extensively characterized for their surface properties by using atomic force microscopy (AFM), photoinduced force microscopy (PiFM), X-ray photoelectron spectroscopy (XPS), moisture adsorption measurements, and contact angle measurements. To assess fouling-release and antifouling properties, laboratory biological assays were conducted with five common marine fouling organisms: Navicula incerta, Celluphaga lytica, Ulva linza, Chlorella vulgaris, and Amphibalanus amphitrite. Notably, 1k or 5k PDMS with a polyglycerol branching ratio of 10:1 or 15:1 emerged as the best performers across a diverse array of laboratory biological assays.

Surfactant-Free Stable Aqueous Shortwave Infrared Amphiphilic π-Conjugated Polymer Nanoparticles.

Novel amphiphilic π-conjugated polymer nanoparticles tailored to efficiently absorb in the near-infrared II (NIR-II) region of the electromagnetic spectrum (>1000nm) are presented. To achieve this, it is statistically introduced triethylene glycol substituted bithiophene moieties in various contents into a polymer backbone consisting of alternating thiophene and [1,2,5]thiadiazolo[3,4-g]quinoxaline. Through systematic modifications of monomer ratios, four amphiphilic conjugated polymers are produced. The presence of hydrophilic side chain, like triethylene glycol monomethyl ether, enhanced the polymer's concentration in aqueous media of up to 470%, versus the D-A thiophene and [1,2,5]thiadiazolo[3,4-g]quinoxaline hydrophobic analog polymer, enabling the production of surfactant-free conjugated polymer nanoparticles (CPNs) with higher concentrations (20.3ppm maximum). Subsequently, the impact of this structural fine-tuning on the optical properties of the polymers and their corresponding CPNs are meticulous investigated. In both cases, it is identified the minimum bithiophene content that maintained the absorption spectra above 1000nm at significantly higher concentrations. So, these findings contribute to the extensive prospects of these materials in multiple fields including biomedical and optoelectronic applications.

Synthesis of Amphiphilic Polymer Co‐Networks via the Growth of a Living RAFT Network

Synthesis of Amphiphilic Polymer Co‐Networks via the Growth of a Living RAFT Network

An antigen-capturing and lymph node-targeting nanoparticle for cancer immunotherapy.

Cancer immunotherapy leverages the immune system to combat cancer and has shown promise for many patients. However, its effectiveness is often hampered by an immunosuppressive tumor microenvironment and the low immunogenicity of tumor cells. In this study, we developed an in situ cancer vaccine that integrates chemotherapy and immunotherapy in a single platform. We synthesized two amphiphilic polymers with poly-albumin-binding domains (PABD) that can target the lymph nodes, PABD-PGEA and PABD-PGED. Compared with previous albumin-hijacking strategies utilizing the same albumin-binding domains, PABD-PGEA exhibited approximately six times greater lymph node-targeting ability, demonstrating enhanced antigen-capturing capability. We loaded PABD-PGEA with doxorubicin (DOX), a drug known to induce immunogenic cell death (ICD) in tumor cells, to form DOX@PABD-PGEA nanomicelles. DOX@PABD-PGEA inhibited tumor growth and extended the survival of mice with B16F10 melanoma through chemotherapy and immunotherapy. Notably, DOX@PABD-PGEA prevented tumor recurrence post-surgery by promoting efficient antigen presentation and reversing immunosuppression in the tumor microenvironment. Our findings suggest that DOX@PABD-PGEA, as an antigen-capturing nanoparticle, provides a safe and effective platform for in situ cancer vaccines and improves cancer immunotherapy.

The Preparation of Cyclic Binary Block Polymer Using Bimolecular Homodifunctional Coupling Reaction and Characterization of Its Performance as a Drug Carrier

There is relatively little research on cyclic amphiphilic block polymers, having both hydrophilic and hydrophobic segments placed in the ring and thus resulting in a higher degree of topological restriction, as drug vehicles. Cyclic amphiphilic binary block polymer is synthesized by the click coupling reaction of bimolecular homodifunctional precursors. The results indicate that cyclization between linear polymer precursors is successful if the trace linear by-products generated are ignored, which also suggests that the small molecule bifunctional terminating agent applied in traditional bimolecular homodifunctional ring-closure process can be extended to large molecule. Moreover, the study on the self-assembly behavior of polymers shows that, compared with linear counterparts, the stability and drug loading capacity of micelles based on the resultant cyclic polymer are not significantly improved due to the influence of topological structure and linear impurities. Nevertheless, drug loaded micelles formed by the obtained cyclic polymers still exhibit superior cellular uptake ability. It can be seen that topological effects do play an irreplaceable role in the application performance of polymers. Therefore, the construction and synthesis of cyclic and its derivative polymers with moderate topological confinement and high purity may be a key direction for future exploration of polymer drug delivery carriers.

Synthesis and Characterization of Lipid-Polyzwitterion Diblock Copolymers for Optimizing Micelle Formation to Enhance Anticancer Drug Delivery in 2D and 3D Cell Cultures.

Amphiphilic polymers with distinct polarity differences, known as sharp polarity contrast polymers (SPCPs), have gained much attention for their ability to form micelles with low critical micelle concentrations (CMCs) and potential in anticancer drug delivery. This study addresses the limited research on structure-property relationships of SPCPs by developing various SPCPs and exploring their physicochemical properties and biological applications. Specifically, the superhydrophobic aliphatic palmitoyl (Pal) was coupled to the superhydrophilic zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) to form Pal-pMPC diblock copolymers. Adjusting the lengths of hydrophilic chains allowed the creation of structures with varying hydrophilic-hydrophobic ratios for micelle formation. Comprehensive evaluations were carried out, including particle size, CMC, chain exchange rates, cellular uptake efficiency, and anticancer effectiveness. Our findings indicate that micelles with optimal hydrophilic-hydrophobic ratios significantly enhanced cellular uptake and cytotoxicity in both two-dimensional (2D) and three-dimensional (3D) tumor models, offering valuable insights for designing SPCPs for anticancer drug delivery.

Sialic Acid-Modified NIR-II Fluorophore with Enhanced Brightness and Photoconversion Capability for Targeted Lymphoma Phototheranostics.

Lymphoma is a malignant cancer characterized by a rapidly increasing incidence, complex etiology, and lack of obvious early symptoms. Efficient theranostics of lymphoma is of great significance in improving patient outcomes, empowering informed decision-making, and driving medical innovation. Herein, we developed a multifunctional nanoplatform for precise optical imaging and therapy of lymphoma based on a new photosensitizer (1-oxo-1H-benzoo[de]anthracene-2,3-dicarbonitrile-triphenylamine (OBADC-TPA)). OBADC-TPA is a donor-acceptor (D-A) molecule characterized by a novel small coplanar and strong electron-withdrawing acceptor skeleton, while the OBADC moiety facilitates strong intramolecular charge transfer. OBADC-TPA-based nanoparticles (NPs) were prepared through encapsulation with an amphiphilic polymer and subsequent modification with sialic acid (SA). Both in vitro and in vivo studies demonstrated that NPs-SA possessed good biocompatibility, effective tumor accumulation, high photoacoustic (PA) contrast, bright second near-infrared (NIR-II) fluorescence emission, and efficient photothermal/photodynamic conversion capabilities, which can serve as a multifunctional nanocomposite for targeted PA/NIR-II fluorescence imaging-guided synergistic type I/II photodynamic and photothermal therapy (PDT/PTT) of lymphoma. This work not only provides a new NIR-II fluorophore with a novel acceptor moiety but also offers a new, accurate, and effective approach for the targeted diagnosis and treatment of lymphoma, holding promising prospects for clinical application.

High-k organic-inorganic hybrid dielectric material for flexible thin-film transistors and printed logic circuits.

A new photopolymerizable organic-inorganic (O-I) hybrid sol-gel material, AUP@SiOx-184, has been synthesized and utilized as a gate dielectric in flexible organic thin-film transistors (OTFTs). The previously reported three-arm alkoxy-functionalized silane amphiphilic polymer has yielded stable O-I hybrid materials comprising uniformly dispersed nanoparticles in the sol state. In this study, a photosensitizer was introduced, facilitating curing effects under ultraviolet light. Photo-crosslinking enhances the stability of hydroxyl radicals within inorganic nanoparticles, thereby minimizing device hysteresis. This approach also contributes to achieving a low leakage current and a high dielectric constant (high-k) while maintaining reduced thickness. Moreover, AUP@SiOx-184 films are amenable to patterning through UV photopolymerization and can be successfully produced using printing techniques. Compared to other materials, they exhibit outstanding flexibility and improved insulating capabilities. Additionally, OTFTs incorporating AUP@SiOx-184 layers demonstrate extremely stable driving features on flexible substrates. Selective printing and specific patterning play crucial roles in the fabrication of logic circuits. This synthesis strategy has resulted in integrated logic devices that have successfully demonstrated their functionality, highlighting its value for producing functional O-I hybrid materials. Utilizing AUP@SiOx-184 as a gate dielectric in OTFTs showcases its potential to advance electronic technologies that are both flexible and high-performing.

Glutathione-scavenging natural-derived ferroptotic nano-amplifiers strengthen tumor therapy through aggravating iron overload and lipid peroxidation.

Nanomedicine-driven ferroptosis has emerged as a promising tumor treatment strategy through delivering exogenous iron and aggravating the lethal accumulation of lipid peroxides (LPO). However, the compensatory mechanisms of ferroptosis defense systems in cancer cells compromise the therapeutic efficacy and lead to potential side effects. Herein, a highly effective ferroptotic nano-amplifier is designed to synergistically promote ferroptosis via increasing intracellular labile iron, exacerbating lipid peroxidation and overcoming the defense system. Briefly, a natural-derived amphiphilic polymer composing of chondroitin sulfate (CS), arachidonic acid (AA) and a redox-sensitive linker, cystamine (CYS) is constructed to self-assemble as a GSH-responsive nanodrug delivery system for loading bioactive ingredient Polyphyllin I (PPI) and ferric ion (Fe3+). This nanodrug (CSAA/Fe@PPI) can scavenge the aberrant intracellular GSH via CYS linker, accompanied with the degradation of CSAA/Fe@PPI and the release of PPI, AA and Fe3+. On one hand, the intracellular labile iron level is significantly elevated due to the exogenous delivery of Fe3+ and PPI-induced ferritinophagy. On the other hand, ROS burst and the supplement of AA initiate and propagate the lipid peroxidation chain reaction. Meanwhile, the depletion of intracellular GSH suppresses the GPX4 activity, further strengthening the lethal accumulation of LPO. Consequently, the ferroptotic antitumor efficacy is remarkably improved by systemically aggravating iron overload and lipid peroxidation. Therefore, our study presents an effective strategy to improve ferroptosis-based anti-cancer treatment through multiple intervention routes.

Amphiphilic polymer modification of graphene oxide (AGO) to enhance the barrier and corrosion protection properties of waterborne polyurethane coatings

Amphiphilic polymer modification of graphene oxide (AGO) to enhance the barrier and corrosion protection properties of waterborne polyurethane coatings

Chemical structure of lipoteichoic acid in the probiotic strain Latilactobacillus curvatus CP2998.

Latilactobacillus curvatus, found in various fermented foods, is a promising probiotic with unique health benefits. Lipoteichoic acid (LTA) is a characteristic amphiphilic surface polymer of gram-positive bacteria and exhibits immunomodulatory activities. Despite the structural diversity of LTA among different bacterial species and strains, no information is available on the chemical structure of LTA in L. curvatus. In this study, we aimed to determine the structure of LTA isolated from L. curvatus CP2998. One- and two-dimensional nuclear magnetic resonance spectra of intact LTA revealed that LTA had a glycerolphosphate polymer as a hydrophilic main chain with partial substitutions of α-linked glucose and D-alanine at the hydroxy group at position 2 of the glycerol residue. The anchor glycolipid fraction was obtained by hydrofluoric acid treatment. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry spectrum of the anchor glycolipid revealed that it contained diglucosyldiacylglycerol and diglucosylmonoacylglycerol. Our results suggest that L. curvatus CP2998 possesses a typical type I LTA structure; however, the lactic acid bacteria-specific anchor glycolipid structures, such as tri- or tetra-saccharides and three fatty acid residues, were not identified.

Engineering Acid-Promoted Two-Photon Ratiometric Nanoprobes for Evaluating HClO in Lysosomes and Inflammatory Bowel Disease.

HClO is considered a potential contributing factor and biomarker of inflammatory bowel disease (IBD). Accurate monitoring of lysosomal HClO is important for further developing specific diagnostic and therapeutic schedules for IBD. However, only rare types of fluorescent probes have been reported for detecting HClO in IBD so far. Herein, an acid-promoted two-photon semiconducting polymer dot (Lyso-RS Pdot) with dual emission in green and red channels and dual-sensing sites is successfully fabricated with two newly designed polymers NADE-PSMA and PFNA-10TBT as precursors. The red conjugated polymer PFNA-10TBT with pH-inert and HClO-sensitive units is employed to evaluate the HClO concentration in turn-off fluorescence. Meanwhile, the amphiphilic green fluorescent polymer NADE-PSMA sensitive to pH and HClO is employed to evaluate the pH value or HClO concentration in turn-on fluorescence. The resultant Lyso-RS Pdots not only display satisfactory performances for detecting HClO and pH but also achieve accurate two-photon imaging of HClO in lysosomes and the colon of IBD mice based on the distinguished properties such as ratiometric signal output, acid-promoted signal amplification, ultrafast response, and two-photon excitation. The results demonstrate that the HClO level in IBD mice is elevated, and the fast early diagnosis of IBD can be achieved through fluorescence imaging by the proposed Lyso-RS Pdots. This work may provide some solid perspectives for fluorescent diagnosis of H+ and HClO-related diseases.

Triple-action cancer therapy using laser-activated NO-releasing metallomicellar nanophotosensitizer for pyroptosis-driven immune reprogramming.

Cancer photoimmunotherapy represents an intelligent and highly efficient therapeutic approach that harnesses the photothermal effect to precisely target and ablate tumor tissues, while simultaneously modulating the immune system to achieve tumor elimination. The integration of multifunctional therapeutic modalities for combined photoimmunotherapy requires advanced drug delivery systems. However, the design of a single nanoagent capable of serving as a multifunctional nanophotosensitizer remains a significant challenge. In this study, we developed a metallomicellar nanophotosensitizer named TAGNO, which offers a synergistic tri-modal cancer treatment strategy by combining photothermal therapy (PTT), gas therapy (GT), and immunotherapy. The TAGNO nanophotosensitizer consists of a gold nanorod core, responsible for inducing the photothermal effect, coated with an amphiphilic polymer functionalized with tumor cell penetrating peptide to accommodate lipophilic small molecule BNN6, a nitric oxide (NO) donor for GT. We demonstrated that TAGNO exhibited high tumor accumulation, excellent stability, and biocompatibility, ensuring the safe delivery of NO to the tumor site. Upon near-infrared (NIR) laser irradiation, TAGNO effectively raised the temperature within tumor tissues while sparing the surrounding healthy tissues and enabled controlled NO release. Once released, the NO interacts with hydrogen peroxide in the hypoxic tumor microenvironment, forming peroxynitrite (ONOO-), which induces mitochondrial dysfunction and triggers pyroptotic cell death. Pyroptosis induced immunogenic cell death and the subsequent release of tumor antigens, activating cytotoxic T cells and promoting M1 macrophage polarization, effectively controlling both primary and secondary tumor growth. Furthermore, laser-induced NO release facilitated the relaxation of stiff tumor tissues, enhancing blood vessel dilation and oxygenation. This improvement promoted immune cell infiltration while suppressing immunosuppressive cells. Overall, this innovative combination of PTT, GT, and immunotherapy presents a potent and synergistic strategy for the treatment of malignant colon tumors, achieving complete tumor eradication.

Assembly-controlled supramolecular aggregation-induced emission systems based on amphiphilic block polymer hosts

A series of adjustable amphiphilic block polymer hosts with pillar[5]arene units were precisely designed via controlled radical polymerization. Well-defined supramolecular vesicles and/or micelles were constructed with enhanced optical performance.

Development of Tumor-targeting Drug Delivery Systems Based on an Understanding of Polymer Characteristics and the Tumor-specific Environment

Tumor-specific active drug release from macromolecular antitumor drugs after tumor delivery is critical to achieve efficient cellular uptake of the active drug, thereby ensuring therapeutic efficacy. Upon reaching the tumor tissue, protease-facilitated depegylation of pegylated zinc protoporphyrin with ester bonds between PEG and ZnPP (esPEG-ZnPP) occurs, leading to a faster cellular uptake and superior antitumor efficacy compared to PEG-ZnPP with ether bonds (etPEG-ZnPP). This finding provides a viable strategy for achieving efficient tumor-specific drug release by utilizing an ester linkage between PEG and antitumor drugs. Another strategy involves using styrene-maleic acid copolymer (SMA), an amphiphilic polymer. Drug-encapsulating SMA aggregates disintegrate upon interaction with cell membrane components, releasing the encapsulated active drug. The author has demonstrated an improvement in the tumor accumulation of SMA-based macromolecular drugs by conjugating pirarubicin (THP), an anthracycline antitumor drug, with SMA. Furthermore, by conjugating various molecular weights of N-(2-hydroxypropyl)methacrylamide (HPMA) to THP via a hydrazone bond (P-THP, DP-THP, and SP-THP), the author has established a positive correlation between HPMA molecular weight and therapeutic efficacy as well as toxicity. Notably, P-THPs release THP under acidic conditions within tumor tissue; however, this release occurs solely outside tumor cells due to HPMA-mediated inhibition of cellular uptake. The author is currently developing macromolecular anticancer drugs using albumin for the tumor-targeted release of anticancer agents both intra- and extracellularly. The strategic development of tumor-targeting macromolecular antitumor drugs based on a comprehensive understanding of polymer characteristics and the tumor-specific environment is imperative for effective cancer therapy.

Soft and tough cellulose nanocrystals interlocked with polyacrylate-bearing cyanobiphenyl ionogels through a double network strategy.

There are several examples of double network gels prepared from cellulose nanocrystals (CNC) conjugated with water-soluble polymers. However, soft but tough gels composed of mostly CNCs have been challenging to design due to aggregation or precipitation of CNCs at higher concentrations in solvated and gelled systems. We report a general strategy to introduce covalent and non-covalent interactions within cellulose nanocrystals (CNCs) to develop tough, processable, liquid crystalline (LC) gels. A liquid crystalline 12-methylene spacer cyanobiphenyl (CB12OH), is grafted onto acrylic acid via Steglich esterification and subsequently copolymerized with acrylic acid via free radical polymerization to afford an amphiphilic liquid crystalline polymer (LCP), PAACB12-r-PAA. The free carboxyl (COOH) groups from polyacrylic acid (PAA) in the copolymer are randomly interlocked with the hydroxyl (OH) groups of CNC through covalent crosslinking and host-guest supramolecular hydrogen bonding in DMSO and 1-butyl-3-methylimidazolium acetate ionic liquid. The dominant cyanobiphenyl-cyanobiphenyl (CB12-CB12) interactions yield hierarchically structured, tough, free-standing liquid crystalline nanocomposite ionogels. Rheological studies of the interlocked free-standing ionogels display a typical crosslinked gel behavior with the storage moduli (G') ranging 103-104 Pa across the entire angular frequency range. Mechanical properties are tailored by varying the concentration of CNCs in the nanocomposite gel. This facile design provides a general strategy to prepare soft and tough liquid crystalline gels from renewable resources.

Facile construction of polyoxometalate-polymer hybrid nanoparticles with pH/redox dual-responsiveness.

Responsive nanomaterials have emerged as promising candidates for advanced drug delivery systems (DDSs), offering the potential to precisely target disease sites and enhance treatment efficacy. To fulfil their potential, such materials need to be engineered to respond to specific variations in biological conditions. In this work, we present a series of pH/redox dual-responsive hybrid nanoparticles featuring an amphiphilic shell polymer and a pH-responsive core polymer. These nanoparticles incorporate a polyoxometalate (POM), specifically the cobalt(iii)-substituted borotungstate ([BIIIW11O39CoIII]6-), loaded through coordination chemistry between the encapsulated CoIII ions of the POM and pyridyl functional groups on the core polymer. The resulting hybrid nanoparticles show potential for controlled release with excellent stability at physiological pH, and efficient particle disassembly in response to the combination of pH and redox stimuli. Disassembly is proposed to occur following a two step mechanism. Structural rearrangement of the nanoparticle occurs on acidification followed by destabilization of the coordination bond between the polyanion and the pyridyl functionality in the core polymer following reduction. In this system, the POM acts in a novel role as a redox active structural cross-linker. These hybrid dual-responsive nanoparticles, featuring superior colloidal stability under extracellular conditions and controllable disintegration in response to the dual stimuli of acidic pH and redox conditions, provide a novel platform for the controlled intracellular release of therapeutics.