Series Of Polymers Research Articles

YAP/TAZ Inhibitor-Based Drug Delivery System for Selective Tumor Accumulation and Cancer Combination Therapy.

The YES-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are two important transcriptional coactivators that are often aberrantly activated in cancer cells. Their dysregulation promotes cancer development and can confer resistance to anticancer therapies. Therefore, the pharmacological inhibition of YAP/TAZ presents a promising approach for treating tumors with heightened YAP/TAZ activity. However, the clinical use of a known YAP/TAZ inhibitor, niflumic acid (NA), is limited by its poor in vivo half-life. To improve its bioavailability, we developed a series of NA-based prodrug polymers and investigated the impact of NA monomer units on the physicochemical properties of their self-assembled nanoparticles. The optimal pNA polymer was selected as a prodrug micellar nanocarrier to load hydrophobic receptor tyrosine kinase inhibitors (RTKIs) for combination therapy. The nanocarrier selectively accumulated in the tumor and synergistically inhibited tumor growth with the cargo RTKIs, particularly Dasatinib, introducing a nanocombination therapy enhanced breast cancer treatment.

Engineering the Hydrophilic-Hydrophobic Interface of Polymeric Micelles by Cationic Blocks for Enhanced Chemotherapy.

The cationic surface charge critically influences the biological functions and therapeutic outcomes of the cancer nanomedicines. However, the basic correlation between the cationic group categories and their therapeutic efficacy has not been elucidated. In this study, cationic polymeric nanoparticles with amino groups (primary, tertiary, and quaternary amines) as the single variable were leveraged to investigate the various effects of amino species for enhanced antitumor chemotherapy. The nanoparticles were constructed from a series of triblock polymers with varying cationic repeating units at the hydrophilic-hydrophobic interface. Our results suggested that quaternary ammonium outperforms its primary and tertiary counterparts in destroying mitochondrial membranes to induce apoptosis, penetrating deep inside the tumor tissue, and damaging tumor vasculatures. As a result, we were able to effectively inhibit tumor growth in mice by a quaternary ammonium conjugate without causing significant toxicity. Our work demonstrated that the chemical structures played vital roles in regulating their biological functions and provided valuable information for designing cationic drug delivery systems.

Autodegradable Polymers: Complete Degradation without Any Trigger, Tunable Performance, and Biomedical Applications.

Degradable polymers are an emerging research interest. The innovation of new degradable polymers for biomedical applications is challenging due to strict demands including nontoxicity of polymers and degraded products, complete degradation to avoid polymer residues in the body, and other suitable properties. Here, we demonstrate a series of degradable polymers for sustained-release drug applications synthesized by the alternating copolymerization of cyclic anhydrides and Schiff bases. In addition to common feedstocks, the copolymerization is versatile and catalyst-free, affording polymers incorporating cyclic topologies and in-chain ester and peptoid groups. Particularly, the polymers exhibit self- and autodegradation without any trigger, which is distinct from remaining degradation mechanisms. The degradation performance is widely regulated by the polymer structure and external temperature, resulting in complete degradation from a few hours to several months. Owing to their unique properties, the polymers are approved for biomedical applications, as revealed soundly through cell viability assay, in vitro and in vivo drug release.

Solid-Phase Synthesis of Poly(imino anthraquinone)s for Low-Cost and High-Performance Bipolar Organic Cathode Materials.

Organic polymer cathode materials have emerged as promising candidates for constructing sustainable lithium and post-lithium batteries. However, it remains a significant challenge to synthesize electroactive polymers with the desired energy density and cycling stability in a cost-effective manner. Herein, we present a simple yet effective solid-phase method for synthesizing a series of bipolar quinone-amine polymers, specifically, poly(imino anthraquinone)s (PIAQs). The dehydration polycondensation reaction, occurring at 350 °C between the amino and hydroxy groups of low-cost diaminoanthraquinone and dihydroxyanthraquinone monomers, yields four PIAQ samples with identical repeating units but varied connection patterns. As cathode materials for lithium batteries employing ester-type electrolytes, they exhibit comparable charge-discharge curves and energy densities within 1.5-4.3 V but varying cycling stabilities proportional to their polymerization degrees. For example, despite its lowest-cost monomers, PIAQ-44 demonstrates one of the most outstanding electrochemical performances among polymer cathode materials, boasting a reversible capacity of 248 mA h g-1, an average discharge voltage of 2.53 V, and a high cycling stability (75% capacity retention after 2000 cycles). Moreover, the slight differences in electrochemical performance among the four PIAQs, pertaining to bipolar redox, irreversible deprotonation, and capacity fade, have been thoroughly elucidated to provide constructive insights into quinone-amine polymers.

Study of PVAc/EVA polymer series: Influence of the inter-/intra-molecular interaction ratio on the molecular mobility at the glass transition.

In this work, the molecular mobility at the glass transition of poly(vinyl acetate) (PVAc) and poly(ethylene-co-vinyl acetate) (EVA) amorphous sample series was investigated. The temperature and pressure dependences of the intermolecular interactions were studied from time-temperature-pressure superpositions and from the relaxation time dispersion of the segmental relaxation. The difference in terms of intermolecular interactions due to the lateral group ratio of vinyl acetate (VAc) was then estimated from the activation volume and related to the cooperative behavior. The isobaric fragility and its two contributions (thermal and volumetric) were estimated through high pressure broadband dielectric spectroscopy measurements. The volumetric and thermal contributions show different behaviors as a function of the VAc ratio and as a function of the pressure. Thus, the study of the PVAc/EVA series has allowed us to emphasize that the intramolecular and intermolecular interactions induced by the dipolar pendant groups directly influence the thermal and volumetric contributions to the isobaric fragility.

High‐Performance Solution Processable Single‐Emitting‐Layer White Circularly Polarized Electroluminescence

AbstractAchieving efficient circularly polarized white organic light‐emitting diode (CP‐WOLED) remains a significant challenge. In this study, a proof‐of‐concept for realizing CP‐WOLED is proposed using an electroplex emission strategy between a chiral thermally activated delayed fluorescence (TADF) emitter and hole‐transporting material. A series of chiral polymers (R/S)‐E‐x (x = 0.02, 0.05, and 0.1) are designed and prepared via random copolymerization of a chiral chromophore and styrene moiety, which shows typical TADF character. The neat film of (R/S)‐E‐0.1 presents distinct chiroptical properties with a dissymmetry factor (|glum|) of 2.8 × 10−3. Notably, solution‐processable, single‐emitting‐layer CP‐WOLEDs are fabricated using these chiral polymers in combination with 1,1‐bis[(di‐4‐tolylamino)phenyl]cyclohexane (TAPC) as the emitter, achieving a record maximum external quantum efficiency of 15.1% and Commission Internationale de lʹeclairage coordinate of (0.36, 0.40). Importantly, these CP‐WOLEDs exhibit an impressive |gEL| value of 2.4 × 10−3. This research provides a straightforward and effective strategy for the realization of high‐performance CP‐WOLED.

Basic-functionalized Ionic Porous Organic Polymers: Triple Roles in One for Highly Efficient and Recyclable Carboxylative Cyclization of CO2 under Mild Conditions.

The transformation of carbon dioxide (CO2) into high-value chemicals is a significant step towards achieving the goal of "carbon neutrality". α-methylene cyclic carbonate, as an intermediate for the synthesis of many important organic compounds, is widely employed in industrial productions. In this work, a series of ionic porous organic polymers (IPOPs) with different basic-functionalized anions were successfully synthesized and adjusted to have certain BET surface areas and high contents of ion sites by post-modification. These basic-functionalized IPOPs could exhibit excellent catalytic performance for carboxylative cyclization of CO2 at 30 oC and 1 bar in presence of silver salts, eliminating the use of extra organic bases. In the whole catalytic reaction, the basic-functionalized anions could play triple roles: enriching CO2 for further transformation, activating the hydroxyl groups of substrates to improve the catalytic performance, while coordinating with Ag atom to stabilize and regenerate catalyst. Notably, the catalytic system of DCX-4-Tet/Ag2O exhibited excellent recyclability, and the yield of α-alkylidene cyclic carbonate was well maintained at 99% after 5 cycles. To the best of our knowledge, the catalytic system was the first example of basic-functionalized IPOPs that played multiple roles for highly efficient CO2 cyclization under mild conditions without any extra organic bases.

Two‐Dimensional Metal Covalent Organic Polymers with Dirhodium(II) Photoreduction Centers for Efficient Nitrogen Fixation

AbstractPhotocatalytic nitrogen fixation is a green method for converting N2 to NH3, but it remains a challenging task due to the lack of effective photocatalysts. Herein, a series of porous metal covalent organic polymers (MCOPs) with the integration of dinuclear rhodium(II) catalytic centers were rationally constructed for photocatalytic N2 fixation. Interestingly, the porous MCOPs had double‐layers two‐dimensional (2D) structures with the coordinated Rh(II) as the point of registry. The photocatalytic experiment showed that Rh‐TAPA with significant donor‐acceptor (D−A) features exhibited a high activity toward NH3 production with a rate of 319.8 μmol g−1 h−1. The electron transfer process, N2 adsorption and activation mechanism of RhCOPs were further investigated through comprehensive characterization, including DFT calculations and in situ characterization. This work provided a valuable insight into the photocatalytic N2 fixation process with porous materials.

Benzonquanmine-based hypercrosslinked polymers for high-efficiency and reversible iodine capture

Designing and preparing of materials for highly efficient and reversible iodine adsorption remains a challenging task. In this study, a series of benzonquanmine-based hypercrosslinked polymers (BHCPs) with nitrogen-rich were designed and synthesized via Friedel-Crafts reaction. The obtained BHCPs showed the high specific surface and high thermal stability. Moreover, the BHCP-3 of BHCPs exhibits excellent iodine capture performance, including ultrahigh iodine vapor adsorption capacity of 619 wt%, the breakthrough iodine experiment of the adsorption capacity reached 2.29 g/g, which is the highest published capacity of HCP adsorbent. And the removal rate of iodine in aqueous solution also reached 92.5 %, and reached 87.4 % the first 10 min, demonstrating rapid adsorption effects. Additionally, the iodine adsorption process of BHCPs conformed to the pseudo-second-order kinetic models, and which were a multi-layer adsorption on non-homogeneous surfaces. Furthermore, the three adsorbents maintained more than 85 % of their iodine capture capacity after five cycles, demonstrating their good recyclability and potential for practical applications.

Tailoring the Properties of Chemically Recyclable Polyethylene-Like Multiblock Polymers by Modulating the Branch Structure.

Developing plastics that fill the need of polyolefins yet are more easily recyclable is a critical need to address the plastic waste crisis. However, most efforts in this vein have focused on high-density polyethylene (PE), while many different types of PE exist. To create broadly sustainable PE with modular properties, we present the synthesis, characterization, and demonstration of materials applications for chemically recyclable PE-like multiblock polymers prepared from distinct hard and soft blocks using ruthenium-catalyzed dehydrogenative polymerization. By altering the branching pattern within the soft blocks, a series of PE-like multiblock polymers were synthesized with tunable glass transition temperatures (Tg) while maintaining consistent high melting temperatures (Tm). A clear U-shape trend between Tg and mechanical properties was found, showcasing their potential as sustainable materials with tailored properties spanning commercial linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE). These materials offer adjustable adhesive strength to metal and demonstrate chemical recyclability and selective depolymerization in mixed plastic streams, promoting circularity and separation.

Synthesis, Structural Analysis and Bright Emission Performance of a New Family of 3D Lanthanide Coordination Polymers Based on 1,3‐phenylenediacetic Acid

AbstractA novel series of isostructural lanthanide coordination polymers with the general formula [Ln2(PDA)3(DMF)2] (where Ln3+= La, Nd, Pr, Tb, Sm and Eu, DMF= N,N’‐dimethylformamide and PDA =1,3‐phenylenediacetate) were hydrothermally synthesized and further characterized by vibrational spectroscopy, thermal analysis, scanning electron microscopy (SEM), energy dispersive X‐ray (EDX) analysis, and powder and single‐crystal X‐ray diffraction techniques. In addition, from the crystallographic data, it was possible to determine the topology of the structure, finding that the network consists of 5‐connected nodes with topological type: nov; 5/4/o8 and point symbol (44.66). To study the luminescence properties regarding potential energy transfers among the building blocks, lanthanum‐based samples doped with Tb (III) and Eu (III) (1 %, 2 %, 5 % and 10 %) were analyzed in solid state. Upon ligand sensitization, 4 f transitions could be observed confirming an “antenna effect” of the PDA ligand. These new compounds are potential materials for the construction of photoluminiscent devices.

Molecular complex inspired design of an efficient copper(II)-containing robust porous polymers for electrochemical water oxidation

Homogeneous copper-bipyridine complexes have been reported as effective catalysts for water oxidation, demonstrating significant potential as alternatives to precious metal-based complexes. However, these complexes face long-term stability and product separation challenges similar to many homogeneous catalysts. Meanwhile, recent studies have underscored the potential of metalated polymer networks, which integrate the structural advantages of polymers with the functional benefits of metal species, making them highly attractive for various applications. Herein, we integrated copper-bipyridine units into porous polymer networks to overcome the limitations of copper-bipyridine complexes. We prepared a series of copper-incorporated polymers (TpBpy-Cux) for electrochemical water oxidation. The electrochemical properties of these polymers were tuned by varying the copper content, with TpBpy-Cu3 presenting the best performance among the samples studied. TpBpy-Cu3 demonstrated a low Tafel slope of 69 mV/decade, achieved a high Faradaic efficiency (FE) of 94 %, and exhibited exceptional stability over 1000 cyclic scans. This study offers insights into the design and optimization of metal-incorporated porous polymer networks building on the foundational understanding of their molecular counterparts for advanced catalytic applications.

Achieving Closed-Loop Recycling of a Semi-Conjugated Polymer Through the Incorporation of Ester Linkers Along the Backbone.

Design strategies to achieve degradation and ideally closed-loop recycling of organic semiconductors have attracted great interest in order to minimize the electronic waste (E-waste). In this work, three ester-incorporated monomers were synthesized by the names of Thiophene-Ester-Ethylene-Thiophene (TEET), Thiophene-Ester-Methylene-Thiophene (TEMT), and Thiophene-Ester-Thiophene (TET), which were co-polymerized via Stille polycondensation with a benzodithiophene (BnDT) π-conjugated unit to yield a series of ester-incorporated polymers: PBnDT-TEET, PBnDT-TEMT, and PBnDT-TET. While the ester-only linker can maintain some extended conjugation in PBnDT-TET, the other two ester linkers having conjugation breaking units result in isolated conjugated segments in PBnDT-TEET and PBnDT-TEMT, evidenced by UV-Vis and CV results. This yields an improved photovoltaic performance of PBnDT-TET compared to PBnDT-TEET. While all three polymers can depolymerize under methanolysis, the alternating co-polymer PBnDT-TEET demonstrates the highest recyclability potential with a single dimethyl ester-functionalized product with an excellent 92 % isolated yield, which can then be repolymerized to reobtain PBnDT-TEET with a 36 % yield. This work provides a framework towards achieving recyclable organic semiconductors to reduce E-waste. Although the incorporation of ester linkers allowed for closed-loop recycling, the low solar cell efficiency of PBnDT-TEET highlights the significant challenge in achieving both recycling and high device performance.

Clickable Plastic Surfaces with Controllable Azide Surface Density

AbstractThis study investigates the surface functionalization of plastic substrates through dip‐coating in azide‐functionalized polymer solutions, followed by a click reaction (i.e., strain‐promoted azide–alkyne cycloaddition). Acrylic, poly(ethylene terephthalate) (PET), and nylon substrates are dip‐coated with a series of polymers containing various azide groups grafted onto the poly(methyl methacrylate‐co‐hydroxyethyl methacrylate) backbone to examine structural effects on the surface density of clickable azide groups. X‐ray photoelectron spectroscopy and fluorescence spectroscopy confirm the subsequent click‐immobilization of cycloalkyne‐tagged fluorescein, which is quantified to calculate the surface density of clickable azide groups. Further investigations demonstrate that the surface density of azide groups can be controlled by manipulating the polymer ratio during dip‐coating, thus enabling the preparation of a linear surface gradient in terms of azide group density. Finally, the microcontact printing (µCP) method is employed to pattern the functionalized surfaces and quantify the functional molecules immobilized on the surface by µCP. This study highlights the adaptability of click chemistry and polymer coating techniques for the advanced functionalization of plastic surfaces for materials science and engineering applications.

Correlation between the Molecular Properties of Semiconducting Polymers of Intrinsic Microporosity and Their Photocatalytic Hydrogen Production.

Increasing the interface area between organic semiconductor photocatalysts and electrolyte by fabricating nanoparticles has proven to be an effective strategy to increase photocatalytic hydrogen production activity. However, it remains unclear if increasing the internal interface by the introduction of porosity has as clear benefits for activity. To better inform future photocatalyst design, a series of polymers of intrinsic microporosity (PIMs) with the same conjugated backbone were synthesized as a platform to independently modulate the variables of porosity and relative hydrophilicity through the use of hydrophilic alcohol moieties protected by silyl ether protecting groups. When tested in the presence of ascorbic acid and photodeposited Pt, a strong correlation between the wettable porosity and photocatalytic activity was found, with the more wettable analogue of two polymers of almost the same surface area delivering 7.3 times greater activity, while controlling for other variables. Transient absorption spectroscopic (TAS) investigation showed efficient intrinsic charge generation within 10 ps in two of the porous polymers, even without the presence of ascorbic acid or Pt. Detectable hole polarons were found to be immediately extracted by added ascorbic acid, suggesting the generation of reactive charges at regions readily accessible to electrolyte in the porous structures. This study directs organic semiconductor photocatalysts design toward more hydrophilic functionality for addressing exciton and charge recombination bottlenecks and clearly demonstrates the advantages of wettable porosity as a design principle.

Synthesis of porous hypercrosslinked polymers from waste polystyrene for efficient CO2 separation

A series of porous hypercrosslinked polymers (HCP-x) were synthesized from waste polystyrene foam via Fridel-Crafts alkylation reaction, aiming to optimize the utilization of waste plastics. The impact of various crosslinkers on the structural characteristics and CO2 adsorption properties of HCP-x was investigated. The results indicated that HCP-x polymers possess high specific surface areas spanning 830–1182 m2 g−1, abundant narrow micropores, and exceptional thermal stability. Notably, HCP-2 exhibited the highest CO2 adsorption capacity of 2.77 mmol g−1 at 273 K and 1.0 bar. These hypercrosslinked polymers also demonstrated a favorable CO2/N2 ideal selectivity and robust cyclic adsorption performance. Breakthrough experiments confirmed the selective adsorption of CO2 from simulated flue gas containing CO2/N2 (15/85). Additionally, the mechanism underlying CO2 adsorption on HCP-x was elucidated by analyzing adsorption thermodynamics and diffusion kinetics. This study not only introduces an innovative method for recycling waste polystyrene foam but also underscores the potential of HCP-x as an effective adsorbent for CO2 capture.

Shape Memory Polymer Bioglass Composite Scaffolds Designed to Heal Complex Bone Defects.

An off-the-shelf scaffold with requisite properties could enable the viable treatment of irregular craniomaxillofacial bone defects. Notably, the scaffold should be conformally fitting, innately bioactive, and bioresorbable. In prior work, we developed a series of shape memory polymer (SMP) scaffolds based on cross-linked poly(ε-caprolactone) (PCL). These were capable of "self-fitting" into complex bone defects when exposed to temperatures above the melt transition of the constituent PCL, either linear-PCL-diacrylate (linear-PCL-DA, Tm ∼55 °C) or star-PCL-tetraacrylate (star-PCL-TA, Tm ∼45 °C) for the potential to improve tissue safety. To achieve favorably increased degradation rates versus PCL-only scaffolds, semi-interpenetrating networks (semi-IPNs) were formed by including linear- or star-poly(l-lactic acid) (PLLA). A potential limitation of these self-fitting scaffolds is the lack of bioactivity, which is essential to osteoinductivity and osseointegration. Herein, analogous composite scaffolds were formed with 45S5 bioglass (BG) to impart bioactivity. The solvent-cast particulate leaching fabrication method was adapted to introduce BG to the fused salt template, resulting in composites with BG concentrated on the pore wall surfaces rather than within pore struts. Composite scaffolds with good pore wall integrity were produced with 2.5, 5, and 10 wt % BG. All composite scaffolds exhibited non-brittle behavior and did not fracture with 85% strain. For semi-IPN composite scaffolds, PLLA crystallinity was lost, and mechanical properties were not appreciably altered versus the non-BG controls. Sufficient retention of PCL crystallinity led to excellent shape memory behavior. The inclusion of 5 and 10 wt % BG led to hydroxyapatite mineralization after 1 day of exposure to simulated body fluid, as well as increased rates of in vitro degradation.

Influence of Molecular Weight and End Groups on Ion Transport in Weakly and Strongly Coordinating Polymer Electrolytes

AbstractIn the development of polymer electrolytes, the understanding of the complex interplay of factors that affect ion transport is of importance. In this study, the strongly coordinating and flexible poly (ethylene oxide) (PEO) is compared to the weakly coordinating and stiff poly (trimethylene carbonate) (PTMC) as opposing model systems. The effect of molecular weight (Mn) and end group chemistry on the physical properties: glass transition temperature (Tg) and viscosity (η) and ion transport properties: transference number (T+), ion coordination strength and ionic conductivities were investigated. The cation transference number (T+) showed the opposite dependence on Mn for PEO and PTMC, decreasing at low Mn for PTMC and increasing for PEO. This was shown to be highly dependent on the ion coordination strength of the system regardless of whether the end group was OH or if the chains were end‐capped. Although the coordination is mainly of the cations in the systems, the differences in T+ were due to differences in anion rather than cation conductivity, with a similar Li+ conductivity across the polymer series when accounting for the differences in segmental mobility.

Engineering Coordinatively Unsaturated Metal Sites in 2D Metal‐Porphyrin Frameworks for Initiator‐Free, Broadband Photocatalytic Synthesis of Ultrahigh Molecular Weight Polymers

AbstractMetal‐organic frameworks bearing coordinatively unsaturated metal sites (CUSs) exhibit distinctive interactions toward guest molecules, thereby presenting intriguing properties in photocatalytic applications. Herein, an adaptable strategy is established to create 2D metal‐porphyrin frameworks while engineering the CUSs based on the use of bivalent metal nodes (Zn2+, Co2+, Cu2+, Ni2+, Cd2+) and Zr‐O clusters. The strong surface‐coordination effect reduces the energy barriers to activate acrylate monomers adsorbed to the nanosheet frameworks, enabling the generation of anion radicals through a broadband light‐induced electron transfer pathway. Particularly, the photocatalytic cycle offers a hole‐mediated deactivation mechanism to regulate the radical concentrations in the polymerization system, while the propagating chains exhibit a surface‐confined growth behavior that significantly inhibits recombination terminations. Extensive mechanistic studies and theoretical calculations reveal the molecular‐level guest‐framework interactions and establish the guidelines to screen metal centers for fabricating valid photocatalysts and monomers compatible with photo‐regulated polymerization. A series of ultrahigh molecular weight polymers with Mn > 1 000 000 and relatively low dispersity (Đ ≈ 1.5) are obtained upon exposure to the full spectrum of visible light. This study provides novel inspirations for harnessing natural sunlight to drive macromolecular synthesis with minimal energy consumption.

Effect of ionic bonding on luminescence properties of histidine maleic anhydride derivatives

Polymeric materials exhibiting room-temperature phosphorescent (RTP) have attracted wide attention for their easy synthesis, low toxicity, and applications in various fields such as data encryption, cell imaging, information security and other fields. Nevertheless, the conventional ways of preparing such materials are mainly focused on doping, which may suffer from phase separation, poor compatibility, and lack of effective methods to promote intersystem crossing and suppress the nonradiative deactivation rates. Herein, a series of polymers with fluorescence and phosphorescence dual emission were prepared by simple radical solution copolymerization. Through rigid ion-bonded cross-linked networks and cross-linked hydrogen-bonded networks between the polymer chains, the non-radiative jumps and achieve ultra-long phosphorescence lifetimes were able to suppress. By suppressing non-radiative transitions through rigid ion-bonded cross-linked networks and intermolecular hydrogen-bonding networks between polymer chains, ultra-long phosphorescence is achieved. Impressively, a LRTP lifetime of up to 815.38 ms in polymers under ambientconditions is set up. Moreover, in this study, phosphorescence emission can be easily tuned by balancing ion radius and charge states. These results outline the construction of polymeric materials, endowing traditional polymers with new characteristics and promising potential applications.