Efficient intracellular delivery of protein drugs is critical for protein therapy. The combination of protein drugs with chemotherapeutics represents a promising strategy in enhancing anti-cancer effect. However, co-delivery systems for efficient delivery of these two kinds of drugs are still lacking because of their different properties. Herein, we show a well-designed delivery system based on dynamic covalent bond for efficient intracellular co-delivery of ribonuclease A (RNase A) and doxorubicin (DOX). Two polymers, PEG-b-P(Asp-co-AspDA) and PAE-b-P(Asp-co-AspPBA), and two 2-acetylphenylboronic acid (2-APBA)-functionalized drugs, 2-APBA-RNase A and 2-APBA-DOX, self-assemble into mixed-shell nanoparticles (RNase A/DOX@MNPs) via dynamic phenylboronic acid (PBA)-catechol bond between PBA and dopamine (DA) moieties. The PBA-catechol bond endows the nanoparticles with high stability and excellent stimulus-responsive drug release behavior. Under the slight acidic environment at tumor tissue, RNase A/DOX@MNPs are positively charged, promoting their endocytosis. Upon cellular uptake into endosome, further protonation of PAE chains leads to the rupture of endosomes because of the proton sponge effect and the cleavage of PBA-catechol bond promotes the release of two drugs. In cytoplasm, the high level of GSH removed the modification of 2-APBA on drugs. The restored RNase A and DOX show a synergistic and enhanced antic-cancer effect. This system may be a promising platform for intracellular co-delivery of protein drugs and chemotherapeutics.

L-glutamic acid (LA) is a bio-based, non-toxic, environmentally friendly material derived from biomass. The present study reports the application of Passerini three-component polymerization (P-3CP) for the straightforward preparation of LA-based light-responsive polyesters (PLTDs) under mild conditions. PLTDs with molar masses up to 8500 g/mol and high yields exceeding 90% are obtained. The chemical structures and light-responsive self-immolative behavior of PLTDs are comprehensively characterized by employing ultraviolet-visible (UV-Vis) spectroscopy, size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) spectroscopy, and liquid chromatography mass spectrometry (LC-MS). Meanwhile, monodisperse PLTD-based doxorubicin-loaded nanoparticles (PLTD-DOX-NP) (size=193 nm, PDI=0.018) are formulated by nanoprecipitation method. Upon light-induced depolymerization, the PLTD-DOX-NP undergoes rapid decomposition, resulting in a burst release of 80% cargo within 13 s. Furthermore, according to biological toxicity tests, the PLTD-NP possesses adequate biosafety, both before and after irradiation. Overall, the incorporation of P-3CP with biorenewable LA-based monomer adheres to the principles of green chemistry, significantly simplifying the synthetic pathway of light-responsive polymers.

Owing to their high significance in fundamental study and diverse applications, stimuli-responsive and fluorescent polymers, particularly those with cluster-triggered emission (CTE) featured by non-conjugated chromophores, have drawn tremendous attention in recent years. In this work, fluorescent and multi-responsive polysiloxane (FRPS) was synthesized by hydrolytic condensation polymerization of 3-aminopropyl methyl diethoxysilane (APMS) with 3-(N-isopropyl propionamide) iminopropyl methyl diethoxysilane (APMS-NIP), which was formed in situ through aza-Michael addition between APMS and N-isopropyl acrylamide. FRPS was not only highly sensitive to temperature, pH and CO₂ in water, but also showed an enhanced and stimuli-adjustable fluorescence emission. The effects of monomer feeding, pH and CO₂ on its lower critical solution temperature and fluorescent property were investigated. FRPS fluorescence emission was ascribed to CTE mechanism. In addition, FRPS was shown to be highly potential as physiological indicator for cell imaging, and for controlled release and trace detection of doxorubicin. This study provides therefore a type of stimuli-responsive and fluorescent material for potential applications in biomedical fields, and it is also of great significance for understanding of the fluorescence mechanism of polysiloxane-based stimuli-responsive polymers.

Semi-interpenetrating (semi-IPN) hydrogels formed by the continuous interpenetration of cross-linked polymer network and linear non-crosslinked polymer with multifunctionality are widely used in biomedical and other fields. However, the negative impact of linear polymer on the homogeneity of the cross-linked network often leads to a decrease in the mechanical properties of semi-IPN hydrogels and severely limits their applications. Herein, a bioinspired hydrogen-bonding induced phase separation strategy is presented to construct the tough semi-IPN polyvinylpyrrolidone/polyacrylamide hydrogels (named PVP_x/PAM hydrogels), including the linear polymer polyvinylpyrrolidone (PVP) and cross-linked polyacrylamide (PAM) network. The resultant PVP_x/PAM hydrogels exhibit unique phase separation induced by the hydrogen bonding between PVP and PAM and affected by the amount of substance of PVP. Meanwhile, the phase separation of PVP_x/PAM hydrogels results in excellent mechanical properties with a strain of 2590%, tensile strength of 0.28 MPa and toughness of 2.17 MJ/m³. More importantly, the hydrogen bonding between PVP and PAM firstly disrupts to dissipate energy under external forces, so the PVP_x/PAM hydrogels exhibit good self-recovery properties and outperform chemically cross-linked PAM hydrogels in impact resistance and damping applications. It is believed that the PVP_x/PAM hydrogels with hydrogen-bonding induced phase separation possess more potential application prospects.

Water-soluble copolymers of p-methacrylamidobenzoic acid (MABA) with neutral comonomers (N-vinylpyrrolidone (VP), N-methyl-N-vinylacetamide (MVAA), N-methacryloyl glucosamine (MAG)) and anionic comononer sodium styrene sulfonate (NaSS) were synthesized by radical copolymerization. The interactions between the prepared copolymers and Tb³⁺ ions in aqueous solutions were studied; the significant influence of chemical structure of a comonomer on luminescence intensity of Tb³⁺ complexes with the copolymers was revealed. The luminescence intensity of Tb³⁺ complexes with the copolymers containing N-vinylamide units (VP, MVAA) is three times more intense than that observed for the complexes between Tb³⁺ and MAG-containing copolymers. In the case of NaSS-containing copolymers, the luminescence intensity is controlled by the values of binding constants between Tb³⁺ and MABA and the content of MABA units in a copolymer. The studied copolymers and their complexes with Tb³⁺ have low cytotoxicity and a pronounced antiviral activity against human respiratory syncytial virus.

In this study, a novel iron-based catalyst system, Fe(acac)₃/(isocyanoimino) triptenylphosphorane (IITP)/AlR₃, was employed for the synthesis of syndiotactic 1,2-polybutadiene in hexane. This catalyst system exhibits remarkably high catalytic activity, achieving a polymerization activity of 762 kg_polymer·mol_catalyst⁻¹·h⁻¹ at 50 °C with a [BD]/[Fe] molar ratio of 20000. Furthermore, living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene polymerization. These characteristics were well demonstrated by a narrow molecular weight distribution (PDI≈2.0) of the resulting polybutadiene and a linear relationship between −ln(1 − c) and polymerization time as well as number average molecular weight and polymer yield. The resultant polymer showed a 1,2-selectivity of approximately 76% and stereoregularity ranging from 62% to 73%(rrrr). Additionally, through kinetic studies on polymerization reaction, an apparent activation energy E_a value of this catalytic system was calculated to be 84.98 kJ·mol⁻¹, which suggests that high polymerization temperature favors efficient polymerization.

For practicable elastomeric polyethylene, achieving high catalyst thermal stability and activity, along with precise control of polymer properties such as branching density, molecular weights, and distribution, is crucial but challenging. In this study, two sets of symmetrical α-diimine nickel complexes, each comprising four nickel bromide or chloride complexes, were synthesized and investigated their performance for ethylene polymerization under various reaction conditions. Upon activation with either Et₂AlCl or MMAO cocatalysts, these complexes displayed not only high activity but also generated high molecular weight polyethylenes with controlled polydispersity and a substantial number of branches. The catalyst with the least steric hindrance displayed the remarkable high activity (up to 1.2×10⁷ g·mol⁻¹·h⁻¹). Notably, nickel bromides demonstrated higher activity compared to their chloride counterparts. The investigation into the effect of reaction temperature on catalytic performance revealed that NiBr^Me-MMAO system displayed high thermal stability (activity up to 2.51×10⁶ g·mol⁻¹·h⁻¹ at 100 °C) and consistently yielded high polymer molecular weights with narrow polydispersity over a broad temperature range of 30−100 °C. Of significant note, mechanical analysis of the resulting polyethylene demonstrated excellent ultimate tensile strength and high strain at break. Particularly, the polyethylene sample prepared at 100 °C exhibited ultimate tensile strength up to 10 MPa with 1863% maximum strain at break and a strain recovery of up to 54.9% after ten cycles at a fixed strain of 300%, indicating excellent material properties of prepared thermoplastic polyethylene elastomers (TPE).

The rich phase behavior of block copolymers (BCPs) has drawn great attention in recent years. However, the double diamond (DD) phase is rarely obtained because of the competition between the minimization of interfacial energy and packing frustration. Here, a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network nanostructures. The reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD structure. The resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing temperature. These results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures, demonstrating great potential in nanopatterning and metamaterials.

To simultaneously endow thermal conductivity, high glass transition temperature (T_g) and healing capability to glass fiber/epoxy (GFREP) composite, dynamic crosslinked epoxy resin bearing reversible β-hydroxyl ester bonds was reinforced with boron nitride nanosheets modified glass fiber cloth (GFC@BNNSs). The in-plane heat conduction paths were constructed by electrostatic self-assembly of polyacrylic acid treated GFC and polyethyleneimine decorated BNNSs. Then, the GFC@BNNSs were impregnated with the mixture of lower concentration (3-glycidyloxypropyl) trimethoxysilane grafted BN micron sheets, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate and hexahydro-4-methylphthalic anhydride, which accounted for establishing the through-plane heat transport pathways and avoiding serious deterioration of mechanical performances. The resultant GFREP composite containing less boron nitride particles (17.6 wt%) exhibited superior in-plane (3.29 W·m⁻¹·K⁻¹) and through-plane (1.16 W·m⁻¹·K⁻¹) thermal conductivities, as well as high T_g of 204 °C (T_g of the unfilled epoxy=177 °C). The reversible transesterification reaction enabled closure of interlaminar cracks within the composite, achieving decent healing efficiencies estimated by means of tensile strength (71.2%), electrical breakdown strength (83.6%) and thermal conductivity (69.1%). The present work overcame the disadvantages of conventional thermally conductive composites, and provided an efficient approach to prolong the life span of thermally conductive GFREP laminate for high-temperature resistant integrated circuit application.

In this study, we proposed a novel method that integrates density functional theory (DFT) with the finite field method to accurately estimate the polarizability and dielectric constant of polymers. Our approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric constant. We validated our method using polyethylene (PE) and polytetrafluoroethylene (PTFE) as benchmark materials, and found that it reliably predicted their dielectric constants. Furthermore, we explored the impact of conformation variations in poly(vinylidene fluoride) (PVDF) on its dielectric constant and polarizability. The resulting dielectric constants of α- and γ-PVDF (3.0) showed excellent agreement with crystalline PVDF in experiments. Our findings illuminate the relationship between PVDF’s structural properties and its electrical behavior, offering valuable insights for material design and applications.

Poly(butylene adipate-co-terephthalate) (PBAT) is a promising biodegradable flexible polymer but suffers from slow crystallization rate, making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene (LDPE). This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide (OMBH). PBAT/OMBH composites with various OMBH contents (0 wt%, 0.5 wt%, 0.7 wt%, 1 wt%, 2 wt%, 3 wt% and 5 wt%) were prepared through melt-mixing. The effect of OMBH on the crystallization behavior, morphologies and mechanical properties of PBAT was investigated. The highest nucleation efficiency value of 59.6% was achieved for PBAT with 0.7 wt% OMBH, much higher than that of 22.7% for PBAT with 0.7 wt% talc. Atomic force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of PBAT. Fourier transform infrared spectroscopy (FTIR) combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole N―H···O＝C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of crystallization. The presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical properties. This work is essential for preparing PBAT with high crystallization rate, enhancing its potential applications in injection-molded products.

High speed sintering, a new powder-bed fusion additive manufacturing technology, utilizes infrared lights (IR) to intensely heat and melt polymer powders. The presence of defects such as porosity, which is associated with particle coalescence, is highly dependdent on the level of energy input. This study investigate the influcence of energy input on porosity and its subsequent effects on the mechanical properties and microstructures of PEBA parts. The parts were manufactured with a variety of lamp powers, resulting in a range of energy input levels spanning from low to high. Subsequebtly, they underwent testing using Archimedes’ method, followed by tensile testing. The porosity, mechanical characteristics, and energy input exhibit a strong correlation; inadequate energy input was the primary cause of pore formation. Using the reduced IR light power resulted in the following outcomes: porosity, ultimate tensile strength, and elongation of 1.37%, 7.6 MPa, and 194.2%, respectively. When the energy input was further increased, the porosity was reduced to as low as 0.05% and the ultimate tensile strength and elongation were increased to their peak values of 233.8% and 9.1 MPa, respectively.

In unit cell simulations, identification of ordered phases in block copolymers (BCPs) is a tedious and time-consuming task, impeding the advancement of more streamlined and potentially automated research workflows. In this study, we propose a scattering-based automated identification strategy (SAIS) for characterization and identification of ordered phases of BCPs based on their computed scattering patterns. Our approach leverages the scattering theory of perfect crystals to efficiently compute the scattering patterns of periodic morphologies in a unit cell. In the first stage of the SAIS, phases are identified by comparing reflection conditions at a sequence of Miller indices. To confirm or refine the identification results of the first stage, the second stage of the SAIS introduces a tailored residual between the test phase and each of the known candidate phases. Furthermore, our strategy incorporates a variance-like criterion to distinguish background species, enabling its extension to multi-species BCP systems. It has been demonstrated that our strategy achieves exceptional accuracy and robustness while requiring minimal computational resources. Additionally, the approach allows for real-time expansion and improvement to the candidate phase library, facilitating the development of automated research workflows for designing specific ordered structures and discovering new ordered phases in BCPs.