Metal–organic frameworks (MOFs) are an interesting and useful class of coordination polymers, constructed from metal ion/cluster nodes and functional organic ligands through coordination bonds, and ...have attracted extensive research interest during the past decades. Due to the unique features of diverse compositions, facile synthesis, easy surface functionalization, high surface areas, adjustable porosity, and tunable biocompatibility, MOFs have been widely used in hydrogen/methane storage, catalysis, biological imaging and sensing, drug delivery, desalination, gas separation, magnetic and electronic devices, nonlinear optics, water vapor capture, etc. Notably, with the rapid development of synthetic methods and surface functionalization strategies, smart MOF‐based nanocomposites with advanced bio‐related properties have been designed and fabricated to meet the growing demands of MOF materials for biomedical applications. This work outlines the synthesis and functionalization and the recent advances of MOFs in biomedical fields, including cargo (drugs, nucleic acids, proteins, and dyes) delivery for cancer therapy, bioimaging, antimicrobial, biosensing, and biocatalysis. The prospects and challenges in the field of MOF‐based biomedical materials are also discussed.
The synthesis and functionalization of metal–organic frameworks (MOFs) for biomedical applications in the delivery of cargos (drugs, nucleic acids, proteins, and dyes) for cancer therapy, bioimaging, antimicrobial, biosensing, and biocatalysis are overviewed, and the development prospects and challenges of MOF‐based theranostic systems are also discussed.
Nucleases cleave the phosphodiester bonds of nucleic acids and may be endo or exo, DNase or RNase, topoisomerases, recombinases, ribozymes, or RNA splicing enzymes. In this review, I survey nuclease ...activities with known structures and catalytic machinery and classify them by reaction mechanism and metal-ion dependence and by their biological function ranging from DNA replication, recombination, repair, RNA maturation, processing, interference, to defense, nutrient regeneration or cell death. Several general principles emerge from this analysis. There is little correlation between catalytic mechanism and biological function. A single catalytic mechanism can be adapted in a variety of reactions and biological pathways. Conversely, a single biological process can often be accomplished by multiple tertiary and quaternary folds and by more than one catalytic mechanism. Two-metal-ion-dependent nucleases comprise the largest number of different tertiary folds and mediate the most diverse set of biological functions. Metal-ion-dependent cleavage is exclusively associated with exonucleases producing mononucleotides and endonucleases that cleave double- or single-stranded substrates in helical and base-stacked conformations. All metal-ion-independent RNases generate 2',3'-cyclic phosphate products, and all metal-ion-independent DNases form phospho-protein intermediates. I also find several previously unnoted relationships between different nucleases and shared catalytic configurations.
With the rapid development of materials science, porous organic polymers (POPs) have received remarkable attentions because of their unique properties such as the exceptionally high surface area and ...flexible molecular design. The ability to incorporate specific functions in a precise manner makes POPs promising platforms for a myriad of applications in molecular adsorption, separation, and catalysis. Therefore, many different types of POPs have been rationally designed and synthesized to expand the scope of advanced materials, endowing them with distinct structures and properties. Recently, supramolecular macrocycles with excellent host–guest complexation abilities are emerging as powerful crosslinkers for developing novel POPs with hierarchical structures and improved performance, which can be well‐organized at different spatial scales. Macrocycle‐based POPs could have unusual porous, adsorptive, and optical properties when compared to their nonmacrocycle‐incorporated counterparts. This cooperation provides valuable insights for the molecular‐level understanding of skeletal complexity and diversity. Here, the research advances of macrocycle‐based POPs are aptly summarized by showing their syntheses, properties, and applications in terms of separation, sensing, and catalysis. Finally, the current challenging issues in this exciting research field are delineated and a comprehensive outlook is offered for their future directions.
Macrocycles as an emerging class of building blocks are used for porous organic polymers owing to their easy functionalization, unique host–guest properties, modifiable conformations, and tunable chemistry. Facilitated by these features, macrocycle‐based porous organic polymers have attracted considerable attentions in the construction of advanced porous materials and excelled in adsorptive separation, optical sensing, and heterogeneous catalysis.
Severe disease and environmental pollution derived from heavy metal ions has become one of the major problems in global public health. In particular, mercury(II) as one type of highly poisonous ...pollutant can destroy human metabolism, central nervous system, and immune system, representing a critical threat to living systems. Therefore, exploitation of new strategies for designing and synthesizing eco‐friendly, efficient, and economical materials for selective detection and removal of Hg2+ is of great importance. Among the various measures for sensing, detection, and removal of mercury ions, advanced functional systems including nanomaterials, polymers, aggregation‐induced emission luminogens, and porous materials have attracted considerable attention over the past years due to their capabilities of real‐time detection, rapid removal, great anti‐interference, quick response, high selectivity, and low limit of detection. In this review, some efficient techniques and strategies for the detection and removal of mercury in aqueous solutions using the abovementioned functional materials are overviewed and the ways in which these advanced material systems are used to tackle the problem of mercury pollution are also discussed.
The recent advanced systems of mercury(II) ion detection and removal based on nanomaterials, polymers, AIEgens, and porous materials are summarized according to their quick response, high sensitivity, outstanding selectivity, and favorable removal efficiency as sensing platforms. Meanwhile, the development prospects, opportunities, and challenges in the field are also discussed.
Metal–organic frameworks (MOFs)—an emerging class of hybrid porous materials built from metal ions or clusters bridged by organic linkers—have attracted increasing attention in recent years. The ...superior properties of MOFs, such as well‐defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, make them promising candidates as drug delivery hosts. Furthermore, scientists have made remarkable achievements in the field of nanomedical applications of MOFs, owing to their facile synthesis on the nanoscale and alternative functionalization via inclusion and surface chemistry. A brief introduction to the applications of MOFs in controlled drug/cargo delivery and cancer therapy that have been reported in recent years is provided here.
Important research progress of metal–organic framework (MOF)‐based drug/cargo delivery systems and their applications in the field of materials science and biomedicine are introduced, especially in terms of cancer theranostics. This is illustrated by individual MOFs, stimuli‐responsive MOFs, and multifunctional MOFs. Additionally, the challenges and development directions of such nanoplatforms are discussed.
A luminescent conjugated macrocycle polymer (CMP) with strong two‐photon fluorescence property, namely, P5‐TPE‐CMP, is constructed from ditriflate‐functionalized pillar5arene and a ...1,1,2,2‐tetrakis(4‐ethynylphenyl)ethylene (TPE) linker through a Sonogashira–Hagihara cross‐coupling reaction. Significantly, in sharp contrast with the corresponding conjugated microporous polymer without synthetic macrocycles, P5‐TPE‐CMP shows an outstanding stability against photobleaching and exhibits highly selective cation sensing capability toward Fe3+ at different excitation wavelengths (both UV and red–near‐infrared regions). Meanwhile, its fluorescence could also be sufficiently quenched by 4‐amino azobenzene, a frequently used organic dye that is certified to be carcinogenic, as compared with a group of common organic compounds. This work paves a new way for enhancing the properties of porous organic polymers through the introduction of supramolecular macrocycles like macrocyclic arenes.
Conjugated macrocycle polymers are first constructed from ditriflate‐functionalized pillararene and a 1,1,2,2‐tetrakis(4‐ethynylphenyl)ethylene linker through a Sonogashira–Hagihara cross‐coupling reaction. They show excellent two‐photon fluorescence (TPF) and serve as a highly efficient TPF sensor for metal ions and organic molecules.
To discover new drugs to combat COVID-19, an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L ...(CTSL) in patients with COVID-19. The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity. Correspondingly, SARS-CoV-2 pseudovirus infection increased CTSL expression in human cells in vitro and human ACE2 transgenic mice in vivo, while CTSL overexpression, in turn, enhanced pseudovirus infection in human cells. CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry, as evidenced by CTSL overexpression and knockdown in vitro and application of CTSL inhibitor drugs in vivo. Furthermore, amantadine, a licensed anti-influenza drug, significantly inhibited CTSL activity after SARS-CoV-2 pseudovirus infection and prevented infection both in vitro and in vivo. Therefore, CTSL is a promising target for new anti-COVID-19 drug development.
The number of DNA polymerases identified in each organism has mushroomed in the past two decades. Most newly found DNA polymerases specialize in translesion synthesis and DNA repair instead of ...replication. Although intrinsic error rates are higher for translesion and repair polymerases than for replicative polymerases, the specialized polymerases increase genome stability and reduce tumorigenesis. Reflecting the numerous types of DNA lesions and variations of broken DNA ends, translesion and repair polymerases differ in structure, mechanism, and function. Here, we review the unique and general features of polymerases specialized in lesion bypass, as well as in gap-filling and end-joining synthesis.
Abstract
We report the observations of FRB 20220912A using the Five-hundred-meter Aperture Spherical radio Telescope. We conducted 17 observations totaling 8.67 hr and detected a total of 1076 bursts ...with an event rate up to 390 hr
−1
. The cumulative energy distribution can be well described using a broken power-law function with the lower- and higher-energy slopes of −0.38 ± 0.02 and −2.07 ± 0.07, respectively. We also report the
L
-band (1–1.5 GHz) spectral index of the synthetic spectrum of FRB 20220912A bursts, which is −2.6 ± 0.21. The average rotation measure value of the bursts from FRB 20220912A is −0.08 ± 5.39 rad m
−2
, close to 0 rad m
−2
and was relatively stable over 2 months. Most bursts have nearly 100% linear polarization. About 45% of the bursts have circular polarization with Signal-to-Noise ratio > 3, and the highest circular polarization degree can reach 70%. Our observations suggest that FRB 20220912A is located in a relatively clean local environment with complex circular polarization characteristics. These various behaviors imply that the mechanism of circular polarization of FRBs likely originates from an intrinsic radiation mechanism, such as coherent curvature radiation or inverse Compton scattering inside the magnetosphere of the FRB engine source (e.g., a magnetar).
One of the major pursuits of biomedical science is to develop advanced strategies for theranostics, which is expected to be an effective approach for achieving the transition from conventional ...medicine to precision medicine. Supramolecular assembly can serve as a powerful tool in the development of nanotheranostics with accurate imaging of tumors and real‐time monitoring of the therapeutic process upon the incorporation of aggregation‐induced emission (AIE) ability. AIE luminogens (AIEgens) will not only enable fluorescence imaging but will also aid in improving the efficacy of therapies. Furthermore, the fluorescent signals and therapeutic performance of these nanomaterials can be manipulated precisely owing to the reversible and stimuli‐responsive characteristics of the supramolecular systems. Inspired by rapid advances in this field, recent research conducted on nanotheranostics with the AIE effect based on supramolecular assembly is summarized. Here, three representative strategies for supramolecular nanomaterials are presented as follows: a) supramolecular self‐assembly of AIEgens, b) the loading of AIEgens within nanocarriers with supramolecular assembly, and c) supramolecular macrocycle‐guided assembly via host–guest interactions. Meanwhile, the diverse applications of such nanomaterials in diagnostics and therapeutics have also been discussed in detail. Finally, the challenges of this field are listed in this review.
Nanotheranostics constructed from aggregation‐induced emission luminogens via supramolecular assembly have been extensively studied during the past decades and exhibit great potential in personalized and precision medicine. This advanced strategy also facilitates the development of integrated systems combining diagnosis and therapy.
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