Macromolecular Rapid Communications最新文献

Cholesteric liquid crystals (CLCs) can be encapsulated within liquid crystal microcapsules (CLCMs) via ultrasonic emulsification, and this microcapsule structure offers advantages in liquid crystal (LC) orientation control and stability. However, CLCMs still face challenges in multiple stimulus responsiveness. In this study, polymerizable LC monomers are introduced as the core filler of CLCMs and polymerized under UV irradiation to form polymer networks. As a result, the structural color of the film changes, and the patterned coloration of the final prepared film gradually disappears upon exposure to sunlight. Furthermore, with the temperature increasing, the pattern of the film first appears and then disappears, ultimately rendering the film completely transparent. Overall, the results show that the CLCM films incorporating polymerizable LC core exhibit multi-stimuli responsiveness to light, heat, and humidity, demonstrating the potential of polymerizable CLCMs for advanced applications such as anti-counterfeiting technologies and sensors.

A linear-dendritic polymer has been explored as a drug delivery vehicle for cancer therapy. In this study, we successfully prepared a tumor microenvironment-responsive, dendronized and block poly[N-(2-hydroxypropyl) methacrylamide] (polyHPMA)-based copolymer-doxorubicin conjugate (pHPMA-block-pDendron-DOX) via two-step reversible addition-fragmentation chain transfer (RAFT) polymerization. The conjugate self-assembled into nanoparticles (NPs). Due to the presence of the Gly-Phe-Leu-Gly (GFLG) tetrapeptide and the hydrazone bond in the structure of the conjugate, cathepsin B-responsive degradation and pH-responsive drug release were realized within the tumor microenvironment. The NPs displayed a distinctive cytotoxic effect on 4T1 cells after internalization through endocytosis pathways. Significant improvements in the accumulation of doxorubicin (DOX) from the NPs were observed at the tumor site in a 4T1 murine breast cancer xenograft model, leading to promising anti-cancer effects. In addition, the side effects of DOX were significantly diminished in the NPs at a high dose. The prepared linear-dendritic conjugate could be used as an efficient and safe nanomedicine.

Micellar drug delivery systems have emerged as a versatile platform for improving the solubility, stability, and targeted release of chemo(immuno)therapeutics. This review focuses on micellar formulations that combine two key design principles: the inherent biodegradability of aliphatic poly(carbonate)s and the universal acid-responsive trigger mechanism. These systems are particularly attractive for tumor therapy, where the acidic microenvironment can be exploited for controlled drug release. We differentiate between two major classes: (i) systems employing acid-labile linkages for reversible conjugation of pharmaceutically active compounds, and (ii) systems in which micelle disassembly or polymer backbone degradation is governed by acid-responsive functionalities. Both categories are systematically evaluated according to the chemical motifs enabling acid sensitivity, including oximes, imines, hydrazones, boronate ester, acetals, ketals, and tertiary amines, among others. The review highlights recent advances in synthetic strategies, structure-property relationships, and therapeutic performance, emphasizing how these design elements synergistically enhance drug loading, release kinetics, and biocompatibility. Finally, we discuss current challenges and future directions for translating these smart micellar systems into promising tumor-targeted (immuno-)therapeutics.

Liquid-liquid phase separation (LLPS) of α-synuclein (α-syn) is an early step toward pathogenic aggregation, yet how sequence architecture and ionic strength jointly regulate this process remains unresolved. Here, we combine all-atom and coarse-grained molecular dynamics simulations to connect single-chain conformational ensembles with multichain condensate formation of α-syn. The highly disordered nature of the α-syn monomer is consistently captured by both all-atom simulations and coarse-grained simulations. We find that the LLPS behavior of full-length α-syn is strongly dependent on ionic strength. Low to intermediate NaCl concentrations favor the formation of liquid-like condensates characterized by high internal mobility and continuous exchange with the dilute phase. As ionic strength increases, electrostatic screening weakens intermolecular interactions, and LLPS is progressively attenuated and ultimately suppressed. We next examined the phase-separation propensities of the N-terminal, NAC, and C-terminal fragments. Strikingly, robust phase separation is observed only for the N-terminal region due to electrostatic interactions, whereas the NAC and C-terminal fragments exhibited only weak, short-lived clustering without forming persistent condensates. Together, our multiscale results establish a mechanistic link between salt-mediated electrostatic screening, region-encoded conformational landscapes, and α-syn condensate formation, providing molecular insight into how solution conditions may tune early events along the pathway to aggregation.

Mechanical and thermal properties are the core to determine the application scenarios of biobased polyurethane elastomers (BPUEs). Here, six core properties were studied, including Young's modulus (YM), tensile strength (TS), elongation at break (EB), glass transition temperature (Tg), decomposition temperature at 5% weight loss (Td₅), and the energy dissipation factor (tanδ). We compiled a new dataset comprising more than 1500 samples with comprehensive information in composition, process, structure, and properties. Through domain-knowledge augmented feature engineering, a set of 26 features is sufficient to predict these core properties. Multi-target regression models for YM, TS, and EB delivered coefficients of determination (R²) better than 0.70 from validation and blind tests, and higher than 0.80 in the prediction of the remaining three properties, Tg, Td_5, and tanδ. Features to describe the chemical structure of polyurethane monomers and their formulation are dominant, and they contributed more than 70% of the explainability. Biomass feedstocks, molecular weights for polyols, hard segment contents etc., are important regulatable variables to prepare BPUEs with fitting-for-purpose products, and the stretching rate and the heating rate are also critical to harvest repeatable mechanical and thermal properties. This study provided data-driven insights for the rational design of BPUEs with desired mechanical and thermal properties.

p-Phenylenediamine (PPD) antioxidants play a vital role in protecting diene rubbers from oxidative degradation. However, their strong polarity often leads to migration from the bulk to the surface, adversely affecting product appearance and reducing long-term anti-aging performance, which limits their wider use. To address this, a novel antioxidant, EMA₂-PPDA (designated E₂P), was synthesized by attaching two 3,4-epoxycyclohexylmethyl acrylate (EMA) units to an N-phenyl-p-phenylenediamine (PPDA) core via an epoxy-amine reaction. E₂P exhibits a notable capacity to react during vulcanization. This characteristic can improve its retention within diene rubber matrices, making it less prone to migration compared to the conventional antioxidant 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine). Results show that E₂P provides excellent anti-aging protection in both natural rubber (NR) and butadiene rubber (BR), with the best overall thermal-oxidative stability observed at 3 phr (parts per hundred rubber). In addition, E₂P exhibits a markedly improved resistance to migration compared to 6PPD under the investigated conditions. These findings indicate that introducing acrylate groups represents a promising strategy for improving the migration resistance of PPD-type antioxidants in vulcanizates, without compromising their antioxidative activity.

The influence of molecular chain entanglement on the mechanical performance of polycarbonate (PC) at superhigh strain rates has been investigated, which is valuable for its safety applications like window glazing. The mechanical testing results across a wide strain rate range (0.01-100 s^-1) show that toughness increases with strain rate, but significant deterioration of stiffness and toughness occurs at 100 s^-1. This phenomenon is, for the first time, observed in real time using digital image correlation (DIC), revealing severe stress concentration and strain localization at 100 s^-1. Nevertheless, we find this deterioration is significantly suppressed by the high entanglement density. It strengthens the strain hardening regime and dynamic mechanical analysis (DMA) is showing that both loss modulus and tan δ values increase with entanglement density in the β-relaxation region, indicating enhanced energy dissipation, which may be the underlying origin of the improved ability to resist deformation. This work is providing fundamental insights into tailoring entanglement networks to suppress energy absorption deterioration under extreme deformation conditions.

Fullerenes attract much interest due to the potentials to various applications. However, their insolubility in water and some organic solvents often hinders development. Herein, poly(ethylene glycol) (PEG), polyvinylpyrrolidone (PVP), poly(vinyl alcohol) (PVA), polyacrylic acid (PAA), and Pluronic L64 and 17R4, are attempted for dispersing fullerene in water via ultrasonication, and some of these are found to disperse an exceedingly large amount. The maximum concentration of C₆₀ is achieved with Pluronic L64, being 9.8 g/L (13.6 mm) without re-aggregation for a long time. Electron paramagnetic resonance (EPR) spectroscopy shows a significant amount of radical species existing in the fullerene-polymer complexes, which are stable for several weeks. DLS and TEM exhibit the formation of nanoparticles, and NMR, FT-IR, and MALDI-TOF MS are used to characterize the fullerene nanoparticles-polymer complexes. The aqueous dispersions of the complexes can be dried and redispersed in water and polar organic solvents. Column chromatographic separation is performed to give unreacted fullerene and fullerene-polymer complexes, the latter of which shows a strong EPR signal. Density functional simulations reveal partial electron transfer from the PEG segment to fullerene, which causes charge separation in the complexes, resulting in the excellent dispersibility in water, while the poly(propylene glycol) (PPG) segment likely assists the complexation by hydrophobic interactions with fullerene.

Allyl glycidyl ether and 2-methoxyethyl glycidyl ether were copolymerized via anionic ring-opening polymerization and subsequently functionalized with guanidinium and indole groups through a post-polymerization thiol-ene reaction. This modular approach yielded eight polymers with systematically varied hydrophilic-hydrophobic balance, carrying 50-92 mol% guanidinium and 0-22 mol% indole. The polymers featured molar masses between 10.1 and 15.7 kg/mol with a dispersity of around 1.3. Polyplexes were formulated using plasmid DNA and characterized with respect to their physicochemical properties including DNA binding affinity, surface charge, and particle size as well as their transfection efficiencies and polymer in vitro cytotoxicity. All polymers were able to form stable complexes and protected their cargo against enzymatic degradation. An additional hydrophilic monomer did not influence physicochemical characteristics, but increased polymer cytotoxicity. Transfection studies in CHO-K1 cells revealed a strong dependence on polymer hydrophobicity: polymers with medium indole content outperformed both more hydrophilic and more hydrophobic analogues, reaching efficiencies above the gold standard poly(ethylene imine). These results underline the critical role of balancing hydrophilic and hydrophobic groups in side-chain functionalized poly(glycidyl ether)s for safe and effective gene delivery.

Geometric configuration of C═C bonds along the polymer backbone plays a crucial role in determining the physical properties of the resulting materials. However, the key role of cis/trans-C═C units in the crystallization and physical property of stereoisomeric polymers has not been well understood. Herein, we report a unique series of linear unsaturated polyesters, poly(butene succinate) (PBuS), with the precisely controlled cis/trans-C═C unit contents synthesized via melt polycondensation. High-molecular-weight cis/trans-polyesters without detectable isomerization or saturation of C═C bonds were prepared in the used polycondensation method. We find that the synthesized PBuS was crystallizable across the entire range of cis/trans unit ratios and showed the unique isodimorphic-like crystallization behavior, with an asymmetric pseudo-eutectic point at ∼31% cis-unit content. Notably, cis-PBuS crystallized much faster than its trans-counterpart, highlighting the profound effect of C═C isomerism on crystallization behavior. Mechanical properties of PBuS correlated strongly with the crystallinity and crystalline structure, showing low strength and modulus but high flexibility around the pseudo-eutectic composition. This work elucidates the crucial role of cis/trans isomerism in polymer crystallization and provides a rational way for designing the aliphatic polyesters with tailored physical properties.