最新刊期
卷 55 ， 期 1 ， 2024
- 摘要：Sulfur dioxide (SO2), previously regarded as one of industrial waste gas, has recently been identified as a novel gasotransmitter in living things. SO2 could be endogenously produced from the metabolism of sulfur-containing amino acids. The endogenous SO2 can regulate many biological processes, physiological and pathophysiological events. However, excessive cellular SO2 would cause serious oxidative damages to DNA, proteins, and lipids, and affect the apoptosis-related gene expression in cells. This can be explained by the ability of SO2 to deplete GSH and induce generation of ROS in cell. Thus, SO2 has great potential in cancer treatment. However, the traditional inhalation of SO2 is not suitable for clinical use because of its unpleasant odor. Similarly, using mixed sulfites as donors of SO2 also cannot meet clinical needs due to their rapid excretion from body. To address these issues, a series of stimuli-responsive SO2-releasing small-molecule donors have been developed for controlled release of SO2. Most of these small-molecule SO2 donors exhibit controlled release behaviors and show great potency for therapeutic application. However, the poor water solubility and lack of tumor-targeting ability significantly hamper the clinical translation of these small-molecule SO2 donors. Very recently, polymeric nanomedicines with controlled SO2-releasing ability have been developed through directly conjugating SO2-releasing donors onto the side chains of polymer or loading the SO2-releasing donors inside the polymeric nanocarriers. The resultant polymeric nanomedicines can achieve improved accumulation and targeted release of SO2 in tumor sites, leading to enhanced anti-cancer efficacy and ameliorated side effect. All in all, our review firstly summarizes the chemical structure and release mechanisms of small-molecule SO2 donors, and subsequently, the research progress of SO2-releasing polymeric nanomedicines is highlighted. Finally, the challenges and future perspectives on the development of SO2-releasing polymeric nanomedicines are briefly discussed.关键词：Sulfur dioxide;Polymeric nanomedicines;Drug carrier;Tumor treatment;Gas therapy
- 831
- |
- 224
- |
- 0
发布时间：2024-01-03
Review
- 摘要：Poly(vinyl chloride) (PVC) medical catheters are prone to form bacterial biofilms and result in bacterial infections during application, which pose formidable threat to public health. As the antibiotic molecules are difficult to penetrate into the biofilms to kill bacteria, there is an urgent demand in developing polymer coatings to resist the formation of bacterial biofilms. Herein, the functional molecules of D-tyrosine, which triggers the disassembly of biofilms, polymyxin B, which is able to kill bacteria, and aldehyde-modified dextran, which has good biocompatibility, are modified onto the surface of PVC, and their functions in resisting the formation of bacterial biofilms are studied. The results show that the polymer coatings modified with D-tyrosine can resist the formation of bacterial biofilms on the substrate of PVC and reduce the tissue inflammation caused by bacterial infections. This research provides a new strategy for the manufacturing of biofilm-resisting PVC catheters for medical applications.关键词：bacterial biofilm;D-tyrosine;polymer coating;antibacterial catheter
- 324
- |
- 170
- |
- 0
发布时间：2024-01-03 - 摘要：Thrombus related diseases seriously threaten human health. A variety of thrombolytic drugs and antiplatelet agents have been used for the treatment of thrombus related diseases. However, the short circulation half-life, narrow therapeutic window and high bleeding risks seriously restrict their therapeutic effects. To achieve safe and effective thrombolytic therapy, we herein developed a kind of novel nanomaterial to codeliver thrombolytic drug urokinase (uPA) and antiplatelet agent ticagrelor for targeted thrombolysis. Based on the liquid core nanoparticles (LCN), we first loaded ticagrelor in LCN, followed by modification of uPA and poly(ethylene glycol)-Cys-Arg-Glu-Lys-Ala (PEG-CREKA) on the surface with thioketal linker to obtain PEG-LCN-uPA. PEG-LCN-uPA exhibited effective thrombolysis only in high oxidative microenvironment, indicating its potential for thrombolysis without causing bleeding. Furthermore, owing to the thrombus targeting ability of CREKA peptide, PEG-LCN-uPA achieved effective targeting and accumulation at thrombus site after intravenous injection. Moreover, the thioketal linker was used to conjugate LCN and uPA degraded in response to the oxidative microenvironment at thrombus site, resulting in the release of uPA for further thrombolysis. In the meantime, the detachment of PEG-CREKA allowed the release of ticagrelor for antiplatelet therapy. Animal studies indicated that PEG-LCN-uPA exhibited effective thrombolysis in both mice tail thrombus models and carotid arterial thrombosis model without obvious safety issues. The decrease of sCD40L level indicated the effective reduced activation of platelet, which benefits for long-term antithrombus therapy. With these abilities, PEG-LCN-uPA presented its potential as a feasible strategy for thrombosis-related diseases treatment.关键词：Nanomaterials;Thrombus;Antiplatelet;Urokinase;Oxidative stress
- 255
- |
- 224
- |
- 0
发布时间：2024-01-03 - 摘要：Direct arylation polycondensation (DArP) is an atom-economic and environmentally benign protocol for the synthesis of conjugated polymers. However, this method often suffered from low reactivity and poor selectivity of C－H bonds. In this study, a β-chlorinated thiophene derivative, 3,6-dichlorothieno[3,2-b]thiophene (2ClTT), was used as the C－H monomer for DArP. The introduction of chlorine atoms at the β-positions of thieno[3,2-b]thiophene significantly enhances the reactivity of α-C－H bonds and evades the unwanted C－H activation. Theoretical calculations revealed that the DArP reactivity of 2ClTT is comparable to that of highly reactive β-chlorinated thiophene-based C－H monomers reported in previous literature. Two conjugated polymers, i.e., DPP-2ClTT and IID-2ClTT, were synthesized by using 2ClTT as the C－H monomer and bromothienyl-flanked diketopyrrolopyrrole (DPPThBr) or brominated isoindigo (IIDBr) as the C－Br monomers. The photophysical and electrochemical properties of these two polymers were investigated. The absorption spectrum of DPP-2ClTT was redshift by ⁓200 nm compared to that of IID-2ClTT. This can be ascribed to the planar backbone of DPP-2ClTT due to the presence of Cl···S intramolecular interactions. Furthermore, the strong electronegativity of chlorine atoms resulted in a reduction of frontier orbital energy levels of the polymers. The HOMO/LUMO energy levels of DPP-2ClTT and IID-2ClTT were -5.35/-3.66 eV and -5.88/-3.73 eV, respectively. The charge transport properties of DPP-2ClTT and IID-2ClTT were characterized by top gate/bottom contact (TG/BC) organic thin-film transistors (OTFTs). Due to the favourable HOMO and LUMO energy levels, as well as the well delocalized HOMO and LUMO orbitals, DPP-2ClTT exhibited ambipolar transport characteristics in OTFT devices with the highest electron and hole mobilities of up to 1.36 and 0.89 cm2/V/s, respectively. However, owing to the deep-positioned HOMO energy level and relatively localized HOMO orbitals, IID-2ClTT displayed n-type transport characteristics in OTFT devices with the highest electron mobility of 0.029 cm2/V/s. The higher electron mobility of DPP-2ClTT, compared to that of IID-2ClTT, can be attributed to its good backbone planarity, highly packing ordered thin-film, and favourable thin-film morphology.关键词：Conjugated polymer;Direct arylation polycondensation;Thiophene derivatives;Charge carrier mobility;Organic thin-film transistors
- 412
- |
- 140
- |
- 0
发布时间：2024-01-03 - 摘要：We have successfully developed and synthesized polymer donor materials with alkyne bonds incorporated into the main chain, using structurally simple and cost-effective materials. The incorporation of alkyne bonds significantly enhances the electron-withdrawing ability of the polymer backbone, leading to a lower highest occupied molecular orbital (HOMO) energy level and a wider bandgap for the polymer. To further explore the potential applications of these materials, we fabricated organic solar cell (OSC) devices by blending the polymer donor materials with the small molecule acceptor material BTP-eC9-4F. These devices exhibited remarkably low non-radiative energy losses and achieved a high open circuit voltage (Voc). Notably, the device based on PBEA demonstrated exceptional performance, with a Voc of 0.91 V, a short-circuit current density (Jsc) of 20.70 mA/cm2, and a power conversion efficiency (PCE) of 10.39%. In comparison, the PBEA-F device only achieved a PCE of 5.50%. These results highlight the superior performance of our designed polymer donor materials, which can be attributed to the introduction of alkyne bonds. The enhanced electron-withdrawing ability of the polymer backbone contributes to the reduction of non-radiative energy losses and the improvement of device performance. Our findings not only demonstrate the potential of these materials for high-performance organic solar cells but also underscore the importance of rational material design in achieving efficient energy conversion.关键词：Organic solar cells;Alkyne bonds;Polymer donor materials;Simple and cost-effective
- 575
- |
- 192
- |
- 2
发布时间：2024-01-03 - 摘要：The arrival of the 5G communication era has brought great convenience to people's lives, and at the same time generated a large amount of electromagnetic pollution. Therefore, there is an urgent need to develop high-performance electromagnetic shielding materials to solve the current serious problem of electromagnetic pollution. In this study, we prepared water-soluble polyacrylic acid/carbon nanotube (PAA/CNT) composites with three-layer impedance gradient structures by multiple coatings. The modification of carbon nanotubes were fully mixed with dispersant under ultrasonic condition to obtain a homogeneous dispersion, which were then centrifuged and dried. The modified carbon nanotubes and water-soluble acrylic acid were mixed in a specific ratio to obtain a homogeneous dispersion. The obtained PAA/CNT composite dispersion was coated on a polyethylene terephthalate (PET) substrate using a brush applicator. The composite coating was obtained by repeated coating after drying the coating. The difference of CNT content between each layer can realize the difference of conductivity, and then build the impedance gradient to realize the introduction-absorption-reflection-re-absorption of electromagnetic wave, so that the electromagnetic shielding performance can be optimized. When the CNT content is 5 wt%, the electromagnetic shielding value is 9.57 dB. With the increase of CNT content to 25 wt%, the electromagnetic shielding value can be up to 28.05 dB. In particular, when the CNT content of each coating is 1%, 5%, 25%, and 1%, 10%, 25%, respectively, the electromagnetic interference shielding efficiency (EMI SE) can be up to more than 20 dB, with a maximum A-power coefficients value of 0.92. Furthermore, waterborne acrylic resins enables the composite materials to maintain excellent weathering resistance. After 200 h of salt spray test, the electromagnetic shielding effect of the material can still achieve 27.85 dB. Such excellent corrosion resistance makes it promising for use in harsh environments. This work provides a strategy for the development of the preparation of electromagnetic dissipative materials without the need for organic solvents, which is environmentally friendly, simple, efficient and cost-effective.关键词：Impedance gradient;Acrylic acid;Coating;5G high frequency band;Low reflectivity electromagnetic shielding
- 269
- |
- 161
- |
- 0
发布时间：2024-01-03 - 摘要：Molecular weight and molecular weight distribution (dispersity, Ð) of polymers have an important effect on polymer properties. In recent years, most methods for regulating dispersity are focused on polymerization in organic solution, but innovative strategies for regulating dispersity in aqueous solution are still scarce. Herein, we report a novel chain transfer agent (CTA) micellar strategy for dispersity control in reversible addition-fragmentation chain transfer (RAFT) polymerization. This is realized by choosing an amphiphilic CTA which is able to form micelle and polymerization was carried out via cascade reactions involving enzymatic deoxygenation and redox initiation. During polymerization, CTA in aqueous solution is first consumed, biasing the micellar equilibrium towards dissolution and consequently broadening of dispersity due to the difference in polymerization time experienced by the polymer chains. Solution pH, sodium chloride, 1-octadecanol, but not sodium dodecanesulfate, all have effect on dispersity control. We show that by varying the solution pH (5.8‒7.1) for polymerizations at a monomer concentration of 1 mol/L, a range of dispersities can be obtained at different degrees of polymerization: for DP 1018, Đ is in the range of 1.33‒1.18; for DP 504, Đ is in the range of 1.39‒1.26; for DP 339, Đ is in the range of 1.51‒1.32. Besides, the dispersity can be increased to 1.55 or reduced to 1.33 after additives were added in aqueous solution (pH=5.8). Generally, higher pH resulted in lower Đ values due to increased degree of ionization of the carboxylic acid group of the CTA, which lowered the CMC and thus the size and stability of the micelles formed by the CTA. The importance of micelles played in dispersity tuning was further confirmed by (1) polymerization at a monomer concentration of 2 mol/L and (2) the use of a totally hydrophilic CTA. In both cases, polymers with narrow dispersities (Đ≤1.17) were obtained regardless of the pH of the solution, which were attributed to no micelle formation in solution at a high organic (monomer) content or the use of a totally hydrophilic CTA. Further kinetic studies were conducted following the changes of the fluorescence of nile red and dynamic light scattering (DLS) during the polymerization. As polymerization proceeded, the fluorescence of nile red experienced a blue shift, indicating the microenvironment of nile red was gradually changed from being inside of the micelle to being surrounded by aqueous solution. In addition, DLS showed a reduction in the size of micelles during the polymerization. The fluorescence and DLS studies suggest disintegration of the micelles during polymerization, and it is this gradually disintegration of CTA micelles that contributes to the broadening of dispersity. However, polymers with a high dispersity still possessed high end-group fidelity, which was confirmed by one-pot synthesis of block copolymers.关键词：Dispersity;Molecular weight distribution;Reversible addition-fragmentation chain transfer polymerization;Chain transfer agent;Micelle
- 551
- |
- 196
- |
- 0
发布时间：2024-01-03 - 摘要：Dynamic crosslinking based on host-guest interaction has shown a number of advantages in constructing injectable hydrogel to be used for biomacromolecules and cell delivery materials. However, it is difficult to dynamically adjust the performance of the hydrogel with only one kind of crosslinking point presented in the structure of the hydrogel. In this study, a two-component supramolecular dynamic cross-linking hydrogel system was designed, employing the host-guest interaction between cucurbit[8]uril (CB[8]) and its homodimer guests to form ternary complex at a ratio of 1/2. The azobenzene guest residues and the phenyl pyridinium guest motifs were introduced into the side chain of hydrogel backbone polymer, in which the azobenzene guest would weakly bind with CB[8] showing faster dynamics, and the phenyl pyridinium salt guest would tightly bind with CB[8] showing slower dynamics. A series of hydrogel materials with the same network structure but dynamically adjustable properties were prepared by adjusting the proportions of these two dynamic cross-linking points. The obtained hydrogel materials could continuously change their properties such as rheology mechanical properties, self-healing, shear thinning, stress relaxation behavior, and macromolecular drug release, all of which are essential in biomedical fields and thus showed great potential in relevant applications.关键词：Cucurbit[8]uril;Hydrogel;Host-Guest Chemistry;Dynamic Cross-linking
- 423
- |
- 163
- |
- 0
发布时间：2024-01-03 - 摘要：Organic-inorganic hybrid porous polymers not only exhibit the diversity of synthesis and flexibility in pore performance control as that of organic porous materials, but also show excellent thermal stability and mechanical properties of inorganic porous materials, and thus play a very important role in the field of porous materials. Polyhedral oligomeric silsesquioxane (POSS) has highly symmetrical structure, is easy to be chemically modified, and has excellent thermal and chemical stability. The silicon oxygen connection at the center of POSS is identical to the Si―O―Si double quaternary ring structure in molecular sieves, making POSS an ideal building block for hybrid porous materials. The Piers-Rubinsztajn reaction catalyzed by B(C6F5)3 avoids the use of expensive precious metal catalysis, which is difficult to completely remove during post-processing. The reaction proceeds under mild conditions and provides an easy route to the formation of Si―O―C linkage. Using the reaction, POSS based organic-inorganic hybrid porous materials were prepared by bonding propeller tetraphenylethylene (TPE) molecules with POSS. Nitrogen adsorption-desorption analysis and thermogravimetric analysis were performed on the hybrid material, which was found to have a combined structure of mesoporous and microporous, and good thermal stability, with a specific surface area of 582 m2/g and Td of 463 ℃.关键词：Organic-inorganic hybrid porous materials;Polyhedral oligomeric silsesquioxane;Piers-Rubinsztajn reaction
- 259
- |
- 169
- |
- 0
发布时间：2024-01-03 - 摘要：Polymethacrylate sulfonate Betaine (PSBMA) is a classic zwitterionic polymer. As a typical hydrogel, it has the characteristics of high water content, super hydrophilicity, low friction coefficient, low biological toxicity but poor mechanical properties. In this work, the natural and easily available κ-carrageenan (κ-CG) is employed to endow the preducor solution with good thixotropy. Then, the preducor solution is coated on the glass surface to form multicomponent double network hydrogel coating. In which, κ-CG network is the first network, acrylamide (AM) and dimethylpropyl sulfonate ethyl methacrylate (SBMA) are the second network monomers, and N,N'-Methylene-bis(acrylamide) (MBAA) as crosslinkage agent. The κ-CG network is further enhanced using zirconium ion (Zr4+) coordination crosslinking. Finally, we get the strong, tough and stable κ-CG/AM/SBMA multicomponent double network hydrogel coating. Benefitted by the double network structure, the mechanical properties of the zwitterion polyelectrolyte hydrogel are significantly strengthened. Its best fracture stress, fracture strain, and Young's modulus reaches 2.51 MPa, 1620.76% and 1.67 MPa, respectively, which basically meets the conditions for its use in the marine environment. The hydrogel coating swells weakly in different medium (water and seawater). Silane coupling agent KH-570 is used to modify the glass surface which help the hydrogel bond to glass surface. The adhesion energy of the hydrogel coating on glass surface obtained from the 90° peel test reaches about 2500 J·m-2. A series of experiments have shown that this κ-CG/AM/SBMA ternary double network hydrogel has excellent hydrophilicity, high breaking strength, good toughness, high modulus and low swelling degree. At the same time, due to the existence of surface hydration layer, the hydrogel coating also behaves drag reduction and excellent performance in antifouling.
- 519
- |
- 465
- |
- 0
发布时间：2024-01-03 - 摘要：Traditional intelligent thermal-responsive gel system is limited by the single response mechanism and poor tunable response temperature, and it is difficult to meet the demand of intelligent gel materials in complex scenes. In this study, a simple strategy for the construction of doubly thermo-responsive ionogels is proposed. By crosslinking modified semi-crystalline poly(ethylene glycol) (PEG) in ionic liquid (IL), the doubly thermo-responsive ionogel with both upper critical solution temperature (UCST) and lower critical solution temperature (LCST) phase behaviors are successfully prepared. The UCST phase behavior of ionogel is based on the melting of PEG crystalline. And the LCST phase behavior is caused by the change of hydrogen bond between PEG and IL affected by temperature. In addition, by adjusting the content of binary components, the polymer chain length and the type of ionic liquid, the thermo-responsive temperature of ionogel can be continuously controlled in a large range under these two phase-behavior mechanisms. The phase transition of ionogel is accompanied by a variety of physical and chemical properties, such as optical transmittance, mechanical properties (3.6‒0.1 MPa) and ionic conductivity. The special characteristics of ionogel make it play a significant role in the fields of smart display, wearable device and flexible sensor.关键词：Doubly thermo-responsive;Upper critical solution temperature;Lower critical solution temperature;Polymer gel;Ionic liquid
- 542
- |
- 289
- |
- 0
发布时间：2024-01-03 - 摘要：Adding compatibilizers is one of the effective ways to improve the poor compatibility between polar lignin (LN) and non-polar rubber, which helps to improve the reinforcing effect of LN. Herein, LN grafted natural rubber (LGN) was prepared using CaCl2/H2O2 as the radical initiating system, which acted as the compatibilizer for the natural rubber (NR)/LN composites. Detailed researches show that CaCl2/H2O2 can not only initiate LN to produce macromolecular free radicals, but also oxidize the double bonds of NR into unsaturated ketones which reduces the molecular weight of NR. Adjusting the feeding order in the grafting process and using CaCl2/H2O2 to treat LN first are helpful to reduce the oxidative degradation of NR and produce more LN macromolecular free radicals. The mechanism of LN grafted NR was explored by the Fourier transform infrared spectroscopy (FTIR) characterization of LN, NR and LGN, that is, the phenol hydroxyl radicals of LN reacted with the methyl groups of NR to form C―O―C bond. Benefiting from the excellent interfacial compatibilization of LGN, the tensile strength and tear strength of NR/LN composite after compatibilization increased by 14.3% and 7.5%, respectively, compared to those before compatibilization. This work provides a new way for preparing the compatibilizer of NR/LN composite, which is of great significance to promote the application of LN in the rubber industry.关键词：Lignin;Natural rubber;CaCl2/H2O2;Graft;Compatibilizer;Composites
- 384
- |
- 190
- |
- 0
发布时间：2024-01-03
Research Article
- Postal code：100190
- Tel：010-62588927 Email：gfzxb@iccas.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备05002797号-8
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0