We report a cationic porphyrin 5,10,15,20‐tetrakis‐(4‐N‐methylpyridyl)‐porphyrin (TMPyP) that can respond to specific bacteria, followed by adaptable photodynamic/photothermal therapy processes. ...TMPyP could be reduced to phlorin by facultative anaerobes with a strong reducing ability such as E. coli and S. typhimurium in hypoxic environments, possessing strong NIR absorption and remarkable photothermal conversion capacity, thus demonstrating excellent antimicrobial activity (>99 %) by photothermal therapy. While in an aerobic environment with aerobic bacteria, TMPyP functioned as a typical photosensitizer that killed bacteria effectively (>99.9 %) by photodynamic therapy. By forming a host–guest complex with cucurbit7uril, the biocompatibility of TMPyP significantly improved. This kind of bacteria‐responsive porphyrin shows specificity and adaptivity in antimicrobial treatment and holds potential in non‐invasive treatments of bacterial infections.
A cationic porphyrin that can respond to specific bacteria followed by adaptable photodynamic/photothermal therapy is reported. It can be reduced to phlorin by reductive facultative anaerobes in hypoxic environments, possessing NIR photothermal conversion ability and demonstrating excellent antimicrobial activity by photothermal therapy. With aerobic bacteria, it functions as an efficient antibacterial photosensitizer by photodynamic therapy.
Covalent thermosets generally exhibit robust mechanical properties, while they are fragile and lack the ability to be reprocessed or recycled. Herein, a new strategy of incorporating noncovalent ...bonds into main‐chains is developed to construct tough and multi‐recyclable cross‐linked supramolecular polyureas (CSPU), which are prepared via the copolymerization of diisocyanate monomers, noncovalently bonded diamine monomers linked by quadruple hydrogen bonds, and covalent diamine/triamine monomers. The CSPU exhibit remarkable solvent resistance and outstanding mechanical properties owing to the covalent cross‐linking via triamine monomer. Through the incorporation of 9.7% and 14.6% quadruple hydrogen bonded diamine monomer, the transparent CSPU films are endowed with superior toughness of 74.17 and 124.17 MJ m−3, respectively. Impressively, even after five generations of recycling processes, the mechanical properties of reprocessed CSPU can recover more than 95% of their original properties, displaying excellent multiple recyclablity. As a result, the superior toughness, remarkable solvent resistance, high transparency, and excellent multiple recyclability are well‐combined in the CSPU. It is highly anticipated that this line of research will provide a facile and general method to construct various cross‐linked polymer materials with superior recyclability and mechanical properties.
A new strategy of incorporating noncovalent bonds into main‐chains is developed to construct tough and multi‐recyclable cross‐linked supramolecular polyureas (CSPU). After five generations of recycling processes, the mechanical properties of reprocessed CSPU can recover more than 95% of their original properties. Overall, CSPU exhibit superior toughness, remarkable solvent resistance, high transparency, and excellent multiple recyclability.
Concerning that the residues of photosensitizers (PS) may cause serious side effects under light, it is of great significant to timely switch‐off PS after photodynamic therapy (PDT). Herein, we ...proposed a supramolecular strategy to regulate the activity of PS, fabricating a supramolecular PS with improved reactive oxygen species (ROS) generation efficiency and accelerated self‐degradation ability. During PDT treatment, the supramolecular PS exhibited good therapeutic efficiency as well as reduced dark toxicity. Moreover, the supramolecular PS could be degraded by ROS generated by itself and lose its PDT activities once PDT treatment finished. In this way, the side effects of PDT can be reduced without sacrificing the therapeutic efficiency. This work provides a novel strategy for smarter PDT beacon to further improve the safety of PDT treatment.
A supramolecular photosensitizer with improved ROS generation efficiency and accelerated self‐degradation ability was reported. Apart from the excellent photodynamic therapeutic efficiency and good biocompatibility, the supramolecular photosensitizer could be photodegraded and lose its PDT activity once PDT treatment finished. Therefore, the side effects of PDT can be reduced without sacrificing the therapeutic efficiency.
Organic radicals are important species with single electrons. Because of their open-shell structure, they are widely used in functional materials, such as spin probes, magnetic materials and ...optoelectronic materials. Owing to the high reactivity of single electrons, they often serve as a key intermediate in organic synthesis. Therefore, tuning the stability of radicals is crucial for their functions. Herein, we summarize covalent and non-covalent approaches to tune the stability of organic radicals through steric effects and tuning the delocalization of spin density. Covalent approaches can tune the stability of radicals effectively and non-covalent approaches benefit from dynamicity and reversibility. It is anticipated that the further development of covalent and non-covalent approaches, as well as the interplay between them, may push the fields forward by enriching new radical materials and radical mediated reactions.
Covalent and non-covalent approaches to tune the stability of organic radicals through steric effects and the delocalization of spin density.
Abstract
Highly efficient recycling of carbon fiber reinforced polymer composites into monomers and fibers is a formidable challenge. Herein, we present a closed‐loop recycling approach for carbon ...fiber reinforced polymer composites using reversible amidation chemistry, which enables the complete recovery of intact carbon fibers and pure monomers. The polymer network, synthesized by amidation between a macromonomer linear polyethyleneimine and a bifunctional maleic anhydride cross‐linker, serves as a matrix for the construction of composites with exceptional mechanical properties, thermal stability and solvent resistance. The matrices can be fully depolymerized under the acidic condition at ambient temperature, allowing the effective separation and recovery of both carbon fibers and the two monomers. The reclaimed carbon fibers retain nearly identical mechanical properties to pristine ones, while pure monomers are recycled with high separation yields (>93 %). They can be reused in for multiple cycles for the manufacture of new composites, whose mechanical properties recover over 95 % of their original properties. This line of research presents a promising approach for the design of high‐performance and sustainable thermoset composites, offering significant environmental and economic benefits.
The diagnosis of biliary atresia (BA) remains a clinical challenge because affected infants have signs, symptoms, and serum liver biochemistry that are also seen in those with other causes of ...neonatal cholestasis (non‐BA). However, an early diagnosis and prompt surgical treatment are required to improve clinical outcome. Recently, the relative abundance of serum matrix metalloproteinase‐7 (MMP‐7) was suggested to have discriminatory features for infants with BA. To test the hypothesis that elevated serum concentration of MMP‐7 is highly diagnostic for BA, we determined the normal serum concentration of MMP‐7 in healthy control infants, and then in 135 consecutive infants being evaluated for cholestasis. The median concentration for MMP‐7 was 2.86 ng/mL (interquartile range, IQR: 1.32‐5.32) in normal controls, 11.47 ng/mL (IQR: 8.54‐24.55) for non‐BA, and 121.1 ng/mL (IQR: 85.42‐224.4) for BA (P < 0.0001). The area under the curve of MMP‐7 for the diagnosis of BA was 0.9900 with a cutoff value of 52.85 ng/mL; the diagnostic sensitivity and specificity were 98.67% and 95.00%, respectively, with a negative predictive value of 98.28%. Conclusion: Serum MMP‐7 assay has high sensitivity and specificity to differentiate BA from other neonatal cholestasis, and may be a reliable biomarker for BA.
The development of non‐covalent synthetic strategy to fabricate efficient photocatalysts is of great importance in theranostic and organic materials. Herein, a fluorochrome N,N′‐dimethyl ...2,5‐bis(4‐pyridinium)thiazolo5,4‐dthiazolediiodide (MPT) was transformed into an efficient photocatalyst through supramolecular dimerization in the cavity of cucurbit8uril (CB8). The host‐enhanced charge transfer interaction within the supramolecular dimer 2MPT‐CB8 dramatically promoted intersystem crossing to produce triplet. In addition, the staggered conformation of 2MPT‐CB8 facilitated the energy transfer and electron transfer of the triplet. As a result, 2MPT‐CB8 could serve as a high‐efficiency photocatalyst for the oxidative hydroxylation of arylboronic acids. This supramolecular dimerization strategy enriches the supramolecular engineering of functional π‐systems. It is anticipated that this strategy can be extended to fabricate various π‐systems with tailor‐made functions.
An efficient fluorochrome was transformed into a high‐performance photocatalyst through the facile fabrication of supramolecular dimer. Owing to the host‐enhanced charge transfer interaction, the intersystem crossing was promoted and the followed electron transfer was facilitated. Therefore, the supramolecular dimer exhibited excellent photocatalytic property for the oxidative hydroxylation of arylboronic acids.
The overexpressed glutathione peroxidase4 (GPX4) and insufficient H2O2 in tumor cells weaken ferroptosis therapy and the elicited anticancer immune response. Herein, a rigid metal‐polyphenol shell ...decorated nanodevice ssPPELap@Fe‐TA is constructed to successfully overcome the drawbacks of ferroptosis therapy. The ssPPELap@Fe‐TA consists of a rigid Fe‐TA network‐based shell and disulfide‐containing polyphosphoester (ssPPE) core with β‐lapachone loading. The rigid Fe‐TA network‐based shell of ssPPELap@Fe‐TA enables its efficient internalization by tumor cell and then disintegrates in the acidic endosome/lysosome to initiate Fe3+/Fe2+ conversion‐driven ferroptosis. The ssPPE core will deplete glutathione (GSH) via the disulfide‐thiol exchange reaction to inactivate GPX4, and also trigger the release of β‐lapachone to significantly increase intracellular H2O2 and then promote Fe3+‐mediated Fenton reaction, eventually achieving strong inhibition of tumor progression. Moreover, ssPPELap@Fe‐TA elicites a robust systemic antitumor immune response by promoting dendritic cells (DCs) maturation and T cell infiltration, and synergizes with anti‐PD‐L1 antibody (a‐PD‐L1) to strikingly suppress 4T1 tumor growth and lung metastasis.
Rigid Fe‐TA network‐based shell and disulfide‐containing polyphosphoester (ssPPE) core with β‐lapachone loading is introduced to construct nanodevices (ssPPELap@Fe‐TA). The nanodevices with the ability of intracellular GSH consumption and Fe/H2O2 self‐supply are used to improve ferroptosis of tumor cells and synergized immunotherapy.
Transition-metal-catalyzed decarbonylation via carbon-carbon bond cleavage is an essential synthetic methodology. Given the ubiquity of carbonyl compounds, the selective decarbonylative process ...offers a distinct synthetic strategy using carbonyl groups as "traceless handles". This reaction has been significantly developed in recent years in many respects, including catalytic system development, mechanistic understanding, substrate scope, and application in the synthesis of complex functional molecules. Therefore, this review aims to summarize the recent progress on transition-metal-catalyzed decarbonylative process, from the discovery of new transformations to the understanding of reaction mechanisms, to reveal the great achievements and potentials in this field. The contents of this review are categorized by the type of chemical bond cleavage in the decarbonylative process. The main challenges and opportunities of the decarbonylative process are also examined with the goal of expanding the application range of decarbonylation reactions.
PDF
