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A Photostable AIEgen for Specific and Real-time Monitoring of Lysosomal Processes
摘要： Lysosomes are recognized as advanced organelles involved in many cellular processes, and are also considered as crucial regulators of cell homeostasis. The current strategies for monitoring activities of lysosomes exhibit some limitations. Herein, we synthesized a novel fluorescent probe named 2M-DPAS with AIE characteristics, which was proved to have significant advantages of good biocompatibility, high selectivity, bright emission and excellent photostability. Based on those, 2M-DPAS can be used to continuously monitor the dynamic changes of lysosomes including autophagy and mitophagy, as well as to track the process of endocytosis of macromolecules in lysosomes, which are benefit to better know about the lysosomes-related diseases.
关键词： Aggregation-induced emission,Lysosomes,Autophagy,Monitoring,Phagocytosis of macromolecules
更新于2025-09-23 15:23:52
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Measurement of brain lactate during visual stimulation using a long TE semia??LASER sequence at 7 T
摘要： Estimation of metabolic changes during neuronal activation represents a challenge for in vivo MRS, especially for metabolites with low concentration and signal overlap, such as lactate. In this work, we aimed to evaluate the feasibility of detecting lactate during brain activation using a long TE (144 ms) semi-LASER sequence at 7 T. 1H spectra were acquired on healthy volunteers (N = 6) during a paradigm with 15 min of visual stimulation. Outer-volume signals were further attenuated by the use of saturation slabs, and macromolecular signals in the vicinity of the inverted lactate peak were individually fitted with simulated Lorentzian peaks. All spectra were free of artefacts and highly reproducible across subjects. Lactate was accurately quantified with an average Cramér-Rao lower bound of 8%. Statistically significant (P < 0.05, one-tailed t-test) increases in lactate (～10%) and glutamate (～3%) levels during stimulation were detected in the visual cortex. Lactate and glutamate changes were consistent with previous measurements. We demonstrated that quantification of a clear and non-contaminated lactate peak obtained with a long TE sequence has the potential of improving the accuracy of functional MRS studies targeting non-oxidative reaction pathways.
关键词： lactate,functional MRS,long TE,semi-LASER,macromolecules
更新于2025-09-19 17:13:59
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Functional Macromolecule‐Enabled Colloidal Synthesis: From Nanoparticle Engineering to Multifunctionality
摘要： The synthesis of well-defined inorganic colloidal nanostructures using functional macromolecules is an enabling technology that offers the possibility of fine-tuning the physicochemical properties of nanomaterials and has contributed to a broad range of practical applications. The utilization of functional reactive polymers and their colloidal assemblies leads to a high level of control over structural parameters of inorganic nanoparticles that are not easily accessible by conventional methods based on small-molecule ligands. Recent advances in polymerization techniques for synthetic polymers and newly exploited functions of natural biomacromolecules have opened up new avenues to monodisperse and multifunctional nanostructures consisting of integrated components with distinct chemistries but complementary properties. Here, the evolution of colloidal synthesis of inorganic nanoparticles is revisited. Then, the new developments of colloidal synthesis enabled by functional macromolecules and practical applications associated with the resulting optical, catalytic, and structural properties of colloidal nanostructures are summarized. Finally, a perspective on new and promising pathways to novel colloidal nanostructures built upon the continuous development of polymer chemistry, colloidal science, and nanochemistry is provided.
关键词： polymer chemistry,nanochemistry,multifunctionality,colloidal synthesis,functional macromolecules,nanoparticle engineering,colloidal science
更新于2025-09-11 14:15:04
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Synergistic Effect of Metal-Organic Framework/Gallic Acid in Enhanced Laser Desorption/Ionization Mass Spectrometry
摘要： Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become an indispensable tool for high throughput analysis of macromolecules, but many challenges still remain in detection of small molecules due to the severe matrix-related background interference in the low-molecular mass ranges (MW < 700 Da). Herein, a gallic acid (GA)-functionalized zirconium1,4-dicarboxybenzene metal-organic framework (MOF) (denoted as UiO-66-GA) was designed to serve as a new substrate and a novel strategy on the basis of the synergistic effect of MOF and GA was developed to enhance LDI process. In comparasion with conventional organic matrices, the UiO-66-GA substrate showed superior LDI performance in the analysis of a wide varity of molecules including amino acids, unsaturated fatty acids, bisphenols (BPs), oligosaccharides, peptides, protein, and polyethylene glycol (PEG) of various average molecular weights from 200 to 10000. Perfluorooctanoic sulfonate (PFOS) was used to evaluate the ability of quantitative analysis and its corresponding limit of detection (LOD) as low as 1 fmol was achieved. High sensitivity and good salt tolerance of the UiO-66-GA-assisted LDI-MS were allowed to determine ultratrace PFOS in the spiked human urine and serum samples. In addition, the synergistic mechanism of MOF and GA in enhanced LDI process was investigated by comprehensively comparing GA- and its analogues functionalized UiO-66, and the results revealed that two aspects contributed to the enhanced LDI process: 1) an enhancement in metal-phenolic coordination system of UiO-66-GA promoted laser absorption and energy transfer; 2) introduction of carboxyl- and hydroxyl groups of GA onto UiO-66 facilitated the LDI process in both positive- and negative ion modes. This work expands a new domain for the MOF applications and provides a promising alternative for various molecule analysis.
关键词： LDI-MS,macromolecules,Synergistic effect,UiO-66-GA,small molecules
更新于2025-09-11 14:15:04
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Silk fibroin nanoparticles for enhanced bio-macromolecule delivery to the retina
摘要： The aim of this study was to investigate intravitreal injection of silk fibroin nanoparticles (SFNs) encapsulating bio-macromolecules, achieving enhanced drug bioavailability and extended retention in retina. SFNs were prepared with regenerated silk fibroin (RSF) using desolvation method with fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) as bio-macromolecular model drug encapsulated. In vitro physicochemical properties and in vitro drug release of FITC-BSA loaded SFNs (FITC-BSA-SFNs) were evaluated. Cytotoxicity, cellular uptake, and retention of FITC-BSA-SFNs were determined in human retinal pigment epithelial cell line (ARPE-19). In addition, in vivo distribution and safety of intravitreally administered FITC-BSA-SFNs were investigated in New Zealand white rabbits. The particle size of FITC-BSA-SFNs was 179.1±3.7 nm with polydispersity index (PDI) of 0.102±0.033 and the zeta potential was greater than -25 mV. FITC-BSA-SFNs exhibited excellent biocompatibility with no cytotoxicity observed within 24 h and 48 h in AREP-19 cells. Compared to FITC-BSA solution, FITC-BSA-SFNs showed enhanced cellular uptake and prolonged retention. Furthermore, FITC-BSA-SFNs achieved accumulated distribution and extended retention in retina in vivo following intravitreal injection compared to a single administration of free drug solution. Therefore, this bio-macromolecule delivery platform based on SFNs could have great potential in the treatment of posterior segment disorders.
关键词： bio-macromolecules,Silk fibroin nanoparticles,ocular drug delivery,posterior segment diseases,intravitreal injection
更新于2025-09-10 09:29:36
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Benzo-15-crown-5 (2,3,5,6,8,9,11,12-octahydrobenzo[b] [1,4,7,10,13]pentaoxacyclopentadecine) and dibenzo-15-crown-5 (6,7,9,10,17,18-hexahydrodibenzo[b,h] [1,4,7,10,13] pentaoxacyclopentadecine as fluorescent probes for physiologically important potassium ion
摘要： Cation recognition plays a vital role in defining advanced functions of macromolecules in nature. An example of such an interaction is the action of a natural antibiotic, valinomycin, that behaves as a potassium ionophore. It encages the cation to transport it across a cell membrane and easily releases it inside the cell. Macrocyclic complexes of some crown ethers mimick alkali ion interactions with natural ionophores. We have synthesized complexes of two crown ethers namely benzo-15-crown-5 (2,3,5,6,8,9,11,12-octahydrobenzo[b][1,4,7,10,13] pentaoxacyclopentadecine) and dibenzo-15-crown-5 (6,7,9,10,17,18-hexahydrodibenzo[b,h][1,4,7,10,13]pentaoxacyclopentadecine with potassium halides (fluoride, chloride, bromide and iodide) in acetonitrile and characterized them by IR, UV, ESI-MS, 1H NMR and 13C NMR techniques. The effect of the anion on the stability of the complexes was observed by 1H NMR studies. The alkali metal ion is held to the oxygen donor atoms of the macrocyclic ring by ion-dipole interactions. The potential of the small ring oxacrown ethers, benzo-15-crown-5 and dibenzo-15-crown-5, to act as probes for potassium ions in dilute solutions (4.1 x 10-4 M) was investigated by recording the variation in the fluorescence spectra of benzo-15-crown-5 and dibenzo-15-crown-5 on complexation with potassium fluoride in acetonitrile and chloroform. The rigidity of the macrocyclic ring and proximity of fluorophore units affected the fluorescence intensity of the complexes.
关键词： fluorescence,complexes,macromolecules,cation recognition,potassium,benzo crown
更新于2025-09-09 09:28:46