Dendritic Polymers Research Articles

Constructing a Spider‐Web Polymer Blocking Layer on Separator for the High‐Loading Li‐S Battery

AbstractThe cycling performance of high‐loading Li−S batteries is still puzzled by the serious shuttle effect of polysulfides. Modifying the commercial separator with polysulfide anchoring materials has been demonstrated as an economical and effective approach to block the polysulfide shuttle. Herein, a cobweb‐like polymer polysulfide‐blocking layer has been constructed via crosslinking between lithium polysilicate (LP) inorganic oligomer and tannic acid (TA) dendritic polymer. Owing to the strongly polar Si−O and Si=O bonds in LP, the spider‐web polymer possesses robust affinity towards polysulfides, indicated by the theoretical calculations. Dendritic polymer TA as the skeleton contributes to effectively exposing the abundant polar functional groups to powerfully capture the polysulfides. As a result, the cycling stability of high‐loading Li−S batteries has been obviously improved. The Li−S battery with sulfur loading of 3.44 mg cm−2 can stably cycle 100 cycles with a high capacity of 685.1 mAh g−1 and columbic efficiency of 99.82 %. Even the sulfur loading increases to 7.15 mg cm−2, the Li−S battery can still deliver a high areal capacity of 5.26 mAh cm−2 after 50 cycles.

Evaluation of shear resistance of dendritic hydrophobic association polymers

Evaluation of shear resistance of dendritic hydrophobic association polymers

Supramolecular Architectures of Dendritic Polymers Provide Irreversible Inhibitor to Block Viral Infection.

In Nature, most known objects can perform their functions only when in supramolecular self-assembled from, e.g. protein complexes and cell membranes. Here, a dendritic polymer is presented that inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an irreversible (virucidal) mechanism only when self-assembled into a Two-dimmensional supramolecular polymer (2D-SupraPol). Monomeric analogs of the dendritic polymer can only inhibit SARS-CoV-2 reversibly, thus allowing for the virus to regain infectivity after dilution. Upon assembly, 2D-SupraPol shows a remarkable half-inhibitory concentration (IC50 30nM) in vitro and in vivo in a Syrian Hamster model has a good efficacy. Using cryo-TEM, it is shown that the 2D-SupraPol has a controllable lateral size that can be tuned by adjusting the pH and use small angle X-ray and neutron scattering to unveil the architecture of the supramolecular assembly. This functional 2D-SupraPol, and its supramolecular architecture are proposed, as a prophylaxis nasal spray to inhibit the virus interaction with the respiratory tract.

Structures Associated with the Borromean Rings’ Complement in the Poincaré Ball

Guided by physical needs, we deal with the rotationally isotropic Poincar´e ball, when considering the complement of Borromean rings embedded in it. We consistently describe the geometry of the complement and realize the fundamental group as isometry subgroup in three dimensions. Applying this realization, we reveal normal stochastization and multifractal behavior within the examined model of directed random walks on the rooted Cayley tree, whose sixbranch graphs are associated with dendritic polymers. According to Penner, we construct the Teichm¨uller space of the decorated ideal octahedral surface related to the quotient space of the fundamental group action. Using the conformality of decoration, we define six moduli and the mapping class group generated by cyclic permutations of the ideal vertices. Intending to quantize the geometric area, we state the connection between the induced geometry and the sine-Gordon model. Due to such a correspondence we obtain the differential two-form in the cotangent bundle of the moduli space.

Preparation of chiral polyether dendrimer and its non-bonding immobilized CALB for high enantioselective synergy resolution of amines

Monodisperse polyethylene glycol monomethyl ether and chiral glycidyl tosylate were utilized as substrates in the synthesis of the chiral monomer unit epoxypropyl polyethylene glycol monomethyl ether (MPEGn-EPO). The initiator propargyl-terminated polyethylene glycol alkyne-PEG3-OH was employed, while the phosphazene base P4-t-Bu facilitated the controlled ROP of MPEGn-EPO, resulting in clickable dendritic P(MPEGn-EPO) with terminal alkyne. The chiral four-arm dendritic polymer 4-Arm-PEG3-Mn was synthesized through a click reaction between 4-Arm-PEG3-N3 and P(MPEGn-EPO) using Cu(PPh3)3Br/CuBr as a catalyst. Candida antarctica lipase B (CALB) was chosen as a model enzyme for the preparation of a non-covalently immobilized biocatalyst (CALB-M) via a simple adsorption process with magnesium silicate and 4-Arm-PEG3-M4-20. The immobilized lipase CALB-M16 demonstrated high enzyme activity in the resolution of racemic amines, yielding chiral amines with enantioselectivity up to 99 % ee. Circular dichroism (CD) analysis indicated the formation of helical conformation in the dendritic polyethers 4-Arm-PEG3-M16-20 in the presence of magnesium silicate at 5 °C. The polyethylene glycol side groups of 4-Arm-PEG3-M16-20 are suggested to potentially form a crown ether-like structure with magnesium ions, which could enhance steric hindrance and induce a right-handed helix. Furthermore, the helical structure of this dendritic polyether is thought to work in synergy with CALB, improving the enantioselective resolution of amines.

Core-Tunable Dendritic Polymer: A Folate-Guided Theranostic Nanoplatform for Drug Delivery Applications.

Clinical application of anticancer drugs is mostly limited due to their hydrophobic nature, which often results in lower bioavailability and lesser retention in systemic circulation. Despite extensive research on the development of targeted drug delivery systems for cancer treatment, delivery of hydrophobic therapeutic drugs to tumor cells remains a major challenge in the field. To address these concerns, we have precisely engineered a new hyperbranched polymer for the targeted delivery of hydrophobic drugs by using a malonic acid-based A2B monomer and 1,6-hexanediol. The choice of monomer systems in our design allows for the formation of higher molecular weight polymers with hydrophobic cavities for the efficient encapsulation of therapeutic drugs that exhibit poor water solubility. Using several experimental techniques such as NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform-infrared (FT-IR), and gel permeation chromatography (GPC), the synthesized polymer was characterized, which indicated its dendritic structure, thermal stability, and amorphous nature, making it suitable as a drug delivery system. Following characterizations, theranostic nanoplatforms were formulated using a one-pot solvent diffusion method to coencapsulate hydrophobic drugs, BQU57 and doxorubicin. To achieve targeted delivery of loaded therapeutic drugs in A549 cancer cells, the surface of the polymeric nanoparticle was conjugated with folic acid. The therapeutic efficacy of the delivery system was determined by various cell-based in vitro experiments, including cytotoxicity, cell internalizations, reactive oxygen species (ROS), apoptosis, migration, and comet assays. Overall, findings from this study indicate that the synthesized dendritic polymer is a promising carrier for hydrophobic anticancer drugs with higher biocompatibility, stability, and therapeutic efficacy for applications in cancer therapy.

Nanodrug delivery materials for digestive system diseases

Digestive system diseases, such as gastritis, gastric ulcers, chronic liver disease, inflammatory bowel disease (IBD), and colorectal cancer, represent a major group of diseases that have high morbidity and death rates worldwide. Their incidence continues to rise owing to factors such as dietary structure changes, accelerated lifestyles, increased environmental pollution, and population aging. Despite the rapid development of the medical technology, the treatment of digestive diseases still faces many challenges, such as addressing drug-resistant Helicobacter pylori infections, treating IBD, and improving the efficacy of advanced gastrointestinal tumor therapies. Fortunately, the emergence of drug-releasing materials has provided new insights that can be used in the treatment of digestive disorders. Drug-releasing materials are a category of specially designed carriers or systems capable of carrying drugs and controlling their release at specific time intervals on demand to achieve the desired therapeutic effect. This article reviews recent research progress of drug-releasing materials used to diagnose and treat digestive disorders. First, the limitations of traditional oral drug delivery methods, such as low bioavailability and nonspecific distribution, are discussed. Second, different types of drug-releasing materials, such as liposomes, dendritic polymers, micelles, nanogels, inorganic nanoparticles, and extracellular vesicles, along with their advantages in terms of improved drug stability, biocompatibility, targeting, and controlled release, are outlined. In addition, the application strategies and preclinical findings of various drug release materials for different digestive disorders are discussed in detail. This Review could help researchers explore more advanced nanomaterials for personalized treatment of drug delivery for digestive disorders.

Bioinspired synthesis of multifunctional, highly stable polymeric templated silver-silica colloids as catalytic and antibacterial coatings for paper

In this paper, a simple, bottom up, bioinspired technique is proposed for the synthesis of highly stable colloids of silica supported spherical silver nanoparticles (SiO2@Ag) that act as efficient catalytic and antimicrobial coatings for an organic substrate, filter paper. The core – shell structure and the highly branched dendritic polymer, poly(ethylene)imine, enabled the precise control of growth rate and morphology of silica and silver nanoparticles. The polymer also enabled the deposition of these nanoparticles onto an organic substrate, filter paper, through immersion by modifying its surface. The catalytic and antibacterial properties of these samples were assessed. The results obtained from this analysis showed a complete degradation of an aqueous pollutant, 4-nitrophenol, for 6 successive catalytic cycles without intermediate purification steps. Furthermore, the polymeric silica-silver suspension proved to express antibacterial activity against both Gram-positive and Gram-negative bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa). The antibacterial properties were evaluated according to the disk diffusion method, whereas the Minimum Inhibitory Concentration was also determined. The samples were examined by Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction analysis, z-potential analysis, Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Spectroscopy.

Self-Assembled Nanoparticles from the Amphiphilic Prodrug of Resiquimod for Improved Cancer Immunotherapy.

Tumor-associated macrophages (TAMs) usually adopt a tumor-promoting M2-like phenotype, which largely impedes the immune response and therapeutic efficacy of solid tumors. Repolarizing TAMs from M2 to the antitumor M1 phenotype is crucial for reshaping the tumor immunosuppressive microenvironment (TIME). Herein, we developed self-assembled nanoparticles from the polymeric prodrug of resiquimod (R848) to reprogram the TIME for robust cancer immunotherapy. The polymeric prodrug was constructed by conjugating the R848 derivative to terminal amino groups of the linear dendritic polymer composed of linear poly(ethylene glycol) and lysine dendrimer. The amphiphilic prodrug self-assembled into nanoparticles (PLRS) of around 35 nm with a spherical morphology. PLRS nanoparticles could be internalized by antigen-presenting cells (APCs) in vitro and thus efficiently repolarized macrophages from M2 to M1 and facilitated the maturation of APCs. In addition, PLRS significantly inhibited tumor growth in the 4T1 orthotopic breast cancer model with much lower systemic side effects. Mechanistic studies suggested that PLRS significantly stimulated the TIME by repolarizing TAMs into the M1 phenotype and increased the infiltration of cytotoxic T cells into the tumor. This study provides an effective polymeric prodrug-based strategy to improve the therapeutic efficacy of R848 in cancer immunotherapy.

Design and fabrication of an electrochemical sensor based on nanocomposite of dendritic polymer and reduced graphene oxide to measure sports nutrition lactate

Design and fabrication of an electrochemical sensor based on nanocomposite of dendritic polymer and reduced graphene oxide to measure sports nutrition lactate

Synthesis of Dendrimer-Like Molecules with Partial Carbon Chain via Iterative Single Unit Monomer Insertions.

Carbon-chain dendritic polymers hold unique properties and promising applications. However, synthesizing carbon-chain dendrimers, beyond conjugated ones, remains a challenge. Here, the use of the iterative single unit monomer insertion technique for synthesizing 2.5 generation partial-carbon-chain dendrimers (G2.5) is described, utilizing bismaleimide as the core, a maleimide-trithiocarbonate conjugate as the branching unit, and indene as the spacer unit, following a divergent growth strategy. The optimized conditions for synthesizing the maleimide-trithiocarbonate branching unit are a bismaleimide to trithiocarbonate ratio of 5:1 and a reaction time of 30 min. The structures are verified using 1H nuclear magnetic resonance, gel permeation chromatography, and matrix-assisted laser desorption/ionization-time of flight mass spectra. A four-arm star polymer is then synthesized using the G2.5 as the core. This synthesis of a partial-carbon-chain dendrimer establishes a foundational step toward creating all-carbon-chain ones and may open new application avenues in material science.

Dendritic polymer prodrug-based unimolecular micelles for pH-responsive co-delivery of doxorubicin and camptothecin with synergistic controlled drug release effect

Combination chemotherapy has been recognized as a more powerful strategy for tumor treatment rather than the single chemotherapy. However, the interactive mechanism of the two hydrophobic chemotherapeutic drugs has not been explored by now. Aiming for a better synergistic effect, such interactive mechanism was investigated in the present work, by designing CPT@DOX-DPUTEA-PEG nanomedicine with encapsulated camptothecin (CPT) and conjugated doxorubicin (DOX). The synergistic controlled drug release effect was found for the two drugs loaded on the different sites of the dendritic polyurethane core. Synergism was achieved on the HepG2 cells with a combination index (CI) of 0.58 in the in vitro cellular experiments. The results demonstrated the promising application of the unimolecular micelles-based nanomedicine with independently loading of two hydrophobic chemotherapeutic drugs.

Non‐linear functional polymers containing selective/cleavable bonds: Synthesis and their biomedical applications

AbstractThe growing interest in functional materials has resulted in the emergence of smart polymers, demonstrating practical performance in various applications especially for biomedical purposes. The properties of functional polymers are mainly determined by the presence of functional groups that differ from those in the main chains. While some polymers are naturally active and considered functional, others require modification for enhanced impact and functionality. Many functional polymers typically have a linear backbone, but very recently the attention has been shifted towards those with specific topologies and architecture, for example, bottlebrushes, stars, dendritic polymers, and gels. Over the past few years, there has been a rising emphasis on integrating selective bonds into complex polymer structures to enhance chain scission in single macromolecules. This review captures the most recent and promising approaches to the design of non‐linear functional polymers containing selective/cleavable bonds and discusses the potential of these materials for biomedical applications.

Dendrimer-induced synthesis of subnano materials and their characterization: establishing atom hybrid science

Abstract The precise molecular design of functional dendritic polymers enables the accumulation of multiple metals within a molecular cage. We have established a synthesizing methodology of metallodendrimers where the number of constituent atoms, the choice of elements, and the composition ratio were precisely controlled through an intramolecular Lewis acid-base interaction at each branch of phenylazomethine dendrons. Due to their inherent capsule effect, chemical reduction of metallodendrimers generates homogeneous subnanoparticles with a particle size of about 1 nm in diameter within the dendrimer cage. Fabricated subnanoparticles show amorphous crystal structures with distorted and fluctuated surface atoms and, with such a unique atomic structure, induce peculiar electronic states, surpassing unique and discrete physical and chemical properties of conventional nanoparticles and bulk metals. In this paper, we review the dendrimer-derived synthesis of atomic hybrid subnanoparticles and its research application established in our laboratory.

Thermal and mechanical properties of aminolyzed‐poly(lactic acid) with amine‐terminated dendritic polymer: Surface and bulk functionalization

AbstractThis study details the effect of surface and bulk functionalization of poly(lactic acid) (PLA) with an amine‐terminated dendritic polymer, poly(amidoamine) (PAMAM), on the thermal and mechanical properties of PLA‐based formulations. Fourier‐transform infrared spectroscopy (FTIR) confirmed the presence of –NH2 groups derived from PAMAM, through emerging new peaks at around 1650 cm−1 associated with –NH bending vibration and separate double peak between 3705 and 3110 cm−1 associated with stretching vibration of –NH amide groups, in both surface and bulk functionalized PLA samples. Differential scanning calorimetry (DSC) measurements revealed a lowering of cold‐crystallization temperature (Tcc) for both surface and bulk functionalized PLA, suggesting that PAMAM served as a nucleating agent. According to thermogravimetric results (TGA), bulk treatment deteriorated the thermal stability of the polymer; while surface modification did not influence the decomposition pathway. Mechanical test results revealed that PAMAM greatly influenced the stiffens and ductility of the composites, with more pronounced changes for higher aminolysis rates. Therefore, the 3‐h PAMAM surface functionalization of PLA limits its affinity to solvents' content and enhances crystallization upon permissible deterioration in mechanical properties.Highlights Development of aminolyzed‐PLA by surface and bulk modification with PAMAM dendritic polymer. PAMAM as a nucleating agent for PLA. Surface modification as the favorable condition to introduce NH2 groups to PLA.

Unsymmetrical Low-Generation Cationic Phosphorus Dendrimers as a Nonviral Vector to Deliver MicroRNA for Breast Cancer Therapy.

The development of nonviral dendritic polymers with a simple molecular backbone and great gene delivery efficiency to effectively tackle cancer remains a great challenge. Phosphorus dendrimers or dendrons are promising vectors due to their structural uniformity, rigid molecular backbones, and tunable surface functionalities. Here, we report the development of a new low-generation unsymmetrical cationic phosphorus dendrimer bearing 5 pyrrolidinium groups and one amino group as a nonviral gene delivery vector. The created AB5-type dendrimers with simple molecular backbone can compress microRNA-30d (miR-30d) to form polyplexes with desired hydrodynamic sizes and surface potentials and can effectively transfect miR-30d to cancer cells to suppress the glycolysis-associated SLC2A1 and HK1 expression, thus significantly inhibiting the migration and invasion of a murine breast cancer cell line in vitro and the corresponding subcutaneous tumor mouse model in vivo. Such unsymmetrical low-generation phosphorus dendrimers may be extended to deliver other genetic materials to tackle other diseases.

Dendritic nanoparticles for immune modulation: a potential next-generation nanocarrier for cancer immunotherapy.

Immune activation, whether occurring from direct immune checkpoint blockade or indirectly as a result of chemotherapy, is an approach that has drastically impacted the way we treat cancer. Utilizing patients' own immune systems for anti-tumor efficacy has been translated to robust immunotherapies; however, clinically significant successes have been achieved in only a subset of patient populations. Dendrimers and dendritic polymers have recently emerged as a potential nanocarrier platform that significantly improves the therapeutic efficacy of current and next-generation cancer immunotherapies. In this paper, we highlight the recent progress in developing dendritic polymer-based therapeutics with immune-modulating properties. Specifically, dendrimers, dendrimer hybrids, and dendronized copolymers have demonstrated promising results and are currently in pre-clinical development. Despite their early stage of development, these nanocarriers hold immense potential to make profound impact on cancer immunotherapy and combination therapy. This overview provides insights into the potential impact of dendrimers and dendron-based polymers, offering a preview of their potential utilities for various aspects of cancer treatment.

Progress in the Research on Branched Polymers with Emphasis on the Chinese Petrochemical Industry

Polymer flooding, one of the main methods for improving crude oil recovery using chemical flooding technology in China, is widely used for actual oil displacement. Partially hydrolyzed polyacrylamide (HPAM) is a commonly used linear polymer in polymer flooding, but it exhibits poor temperature and salt resistance due to its molecular structure. Therefore, branched polymers have been studied. This article provides a review of the specific synthetic methods and current practical applications in the petrochemical field of dendritic polymers and hyperbranched macromolecules. The advantages and disadvantages of each synthetic method for branched polymers are also elaborated. Finally, the application prospects of branched polymers are discussed. The feasibility of branched polymers in large quantities should be further verified through additional field tests, which should address concerns such as synthesis costs and reaction efficiency.

Recent Advances in Micro- and Nano-Drug Delivery Systems Based on Natural and Synthetic Biomaterials.

Polymeric drug delivery technology, which allows for medicinal ingredients to enter a cell more easily, has advanced considerably in recent decades. Innovative medication delivery strategies use biodegradable and bio-reducible polymers, and progress in the field has been accelerated by future possible research applications. Natural polymers utilized in polymeric drug delivery systems include arginine, chitosan, dextrin, polysaccharides, poly(glycolic acid), poly(lactic acid), and hyaluronic acid. Additionally, poly(2-hydroxyethyl methacrylate), poly(N-isopropyl acrylamide), poly(ethylenimine), dendritic polymers, biodegradable polymers, and bioabsorbable polymers as well as biomimetic and bio-related polymeric systems and drug-free macromolecular therapies have been employed in polymeric drug delivery. Different synthetic and natural biomaterials are in the clinical phase to mitigate different diseases. Drug delivery methods using natural and synthetic polymers are becoming increasingly common in the pharmaceutical industry, with biocompatible and bio-related copolymers and dendrimers having helped cure cancer as drug delivery systems. This review discusses all the above components and how, by combining synthetic and biological approaches, micro- and nano-drug delivery systems can result in revolutionary polymeric drug and gene delivery devices.

Enhancing the performance of a modified poly(ether-b-amide) blend membrane by PAMAM dendritic polymer for separation of CO2/CH4

Novel dense membranes were fabricated by blending poly(ether-b-amid), Pebax 1657, as the matrix and a poly(amidoamine) dendritic polymer (PAMAM), as the modifier, to evaluate CO2/CH4 gases separation. The study investigated the effects of PAMAM loading, operating pressure, and temperature on gas permeability and CO2/CH4 pair-gas ideal selectivity. All the membranes were characterized using various analytical techniques, including ATR-FTIR, XRD, SEM, FESEM, DSC, AFM, Tensile Analysis, density, Aging, Stability pure gas permeation, and gas solubility tests. FTIR results confirmed the interaction of PEO and PA segments with PAMAM increased polymer crystallinity, which is in agreement with DSC, XRD, and Tensile Analysis results. The membrane containing 3 wt% PAMAM showed the highest FFV which along with facilitated transport of CO2 by PAMAM, resulted in the highest CO2 permeability equal to 56.9 Barrer at 2 bar and 30 °C (more than 30% higher than the neat Pebax membrane at the same condition). Furthermore, the addition of 1 wt% PAMAM to Pebax increased the CO2/CH4 selectivity to 22.8 at 8 bar and 30 °C (more than 78% higher than the neat Pebax membrane at the same condition). Increasing PAMAM loading and applied pressure resulted in the enhancement of gases solubility, and a better ideal selectivity was obtained, correspondingly, Also higher solubility of CO2 compared with CH4 was confirmed by solubility measurements. It was revealed that gas permeability in the membranes was primarily governed by gas solubility rather than diffusivity. The results demonstrate that the modifying Pebax membrane by PAMAM enhances the separation performance with a negligible change against aging and good stability, which confirms potential applications of Pebax/PAMAM membranes in gas separation processes.