Colorimetric and Ratiometric Chemosensor for Visual Detection of Gaseous Phosgene Based on Anthracene Carboxyimide Membrane

In this work, we reported an anthracene carboxyimide-based chemosensor (AC-Phos) for colorimetric and ratiometric fluorescence detection of highly toxic phosgene, which displayed rapid response (<5 min) toward phosgene with a high selectivity and a low detection limit (2.3 nM). Furthermore, a facile testing membrane with a polystyrene immobilizing chemosensor has been fabricated for real-time visualizing of gaseous phosgene

Construction of a Hierarchical Micro-/Submicro-/Nanostructured 3D-Printed Ti6Al4V Surface Feature to Promote Osteogenesis: Involvement of Sema7A through the ITGB1/FAK/ERK Signaling Pathway

Constructing hierarchical hybrid structures is considered a facile method to improve the osseointegration of implants. Herein, a hierarchical micro-/submicro-/nanostructured surface feature of Ti6Al4V implants (3DAT group) was successfully constructed by combining the inherently formed three-dimensional (3D)-printed microscale topography, acid-etched sub-micropits, and anodized nanotubes. Compared with the classical SLA surface, the microscale topography and sub-micropits increased the three-dimensional space for the cell growth and mechanical stability of implants, while the modification of nanotubes dramatically improved the surface hydrophilicity, protein adsorption, and biomineralization. Most importantly, the 3DAT surface feature possessed excellent osteogenic performance in vitro and in vivo, with the involvement of semaphorin 7A (Sema7A) as revealed by RNA-seq through the ITGB1/FAK/ERK signaling pathway. The present study suggested that the hierarchically structured surface design strategy could accelerate the osseointegration rate of 3D-printed Ti6Al4V implants, promising personalized reconstruction of bone defects

A Water-Soluble “Switching On” Fluorescent Chemosensor of Selectivity to Cd²⁺

Compound 1, a new fluorescent chemosensor signaling via significantly enhanced fluorescence when bound with cation analytes, was synthesized and characterized. This fluorescent chemosensor exhibits its selectivity to Cd2+ among a series of cations in HEPES buffer solution. Its in vitro sensitivity to Cd2+ was demonstrated in the HK-2 cell line with use of confocal microscopy. The mechanistic selectivity and sensitivity of compound 1 to Cd2+ was discussed on the basis of fluorescence, 1H NMR, and mass spectroscopic results

Reversible Fluorescent Probe for Highly Selective and Sensitive Detection of Mercapto Biomolecules

A coumarin-derived complex, Hg2L2, was reported as a highly sensitive and selective probe for the detection of mercapto biomolecules in aqueous solution. The addition of Cys to a 99% aqueous solution of Hg2L2 resulted in rapid and remarkable fluorescence OFF–ON (emission at 525 nm) due to the ligand-exchange reaction of Cys with L coordinated to Hg2+. The increased fluorescence can be completely quenched by Hg2+ and recovered again by the subsequent addition of Cys. Such a fluorescence OFF–ON circle can be repeated at least 10 times by the alterative addition of Cys and Hg2+ to the solution of Hg2L2, indicating that it can be used as a convertible and reversible probe for the detection of Cys. The interconversion of Hg2L2 and L via the decomplexation/complexation by the modulation of Cys/Hg2+ was definitely verified from their crystal structures. Other competitive amino acids without a thiol group cannot induce any fluorescence changes, implying that Hg2L2 can selectively determine mercapto biomolecules. Using confocal fluorescence imaging, L/Hg2L2 as a pair of reversible probes can be further applied to track and monitor the self-detoxification process of Hg2+ ions in SYS5 cells

Amphiphilic Diblock Terpolymer PMAgala‑<i>b</i>‑P(MAA-<i>co</i>-MAChol)s with Attached Galactose and Cholesterol Grafts and Their Intracellular pH-Responsive Doxorubicin Delivery

In this work, a series of diblock terpolymer poly­(6-<i>O</i>-methacryloyl-d-galactopyranose)-<i>b</i>-poly­(methacrylic acid-<i>co</i>-6-cholesteryloxy hexyl methacrylate) amphiphiles bearing attached galactose and cholesterol grafts denoted as the PMAgala-<i>b</i>-P­(MAA-<i>co</i>-MAChol)­s were designed and prepared, and these terpolymer amphiphiles were further exploited as a platform for intracellular doxorubicin (DOX) delivery. First, employing a sequential RAFT strategy with preliminarily synthesized poly­(6-<i>O</i>-methacryloyl-1,2:3,4-di-<i>O</i>-isopropylidene-d-galactopyranose) (PMAIpGP) macro-RAFT initiator and a successive trifluoroacetic acid (TFA)-mediated deprotection, a series of amphiphilic diblock terpolymer PMAgala-<i>b</i>-P­(MAA-<i>co</i>-MAChol)­s were prepared, and were further characterized by NMR, Fourier transform infrared spectrometer (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and a dynamic contact angle testing instrument (DCAT). In aqueous media, spontaneous micellization of the synthesized diblock terpolymer amphiphiles were continuously examined by critical micellization concentration assay, dynamic light scattering (DLS), and transmission electron microscopy (TEM), and the efficacies of DOX loading by these copolymer micelles were investigated along with the complexed nanoparticle stability. Furthermore, in vitro DOX release of the drug-loaded terpolymer micelles were studied at 37 °C in buffer under various pH conditions, and cell toxicities of as-synthesized diblock amphiphiles were examined by MTT assay. Finally, with H1299 cells, intracellular DOX delivery and localization by the block amphiphile vectors were investigated by invert fluorescence microscopy. As a result, it was revealed that the random copolymerization of MAA and MAChol comonomers in the second block limited the formation of cholesterol liquid-crystal phase and enhanced DOX loading efficiency and complex nanoparticle stability, that ionic interactions between the DOX and MAA comonomer could be exploited to trigger efficient DOX release under acidic condition, and that the diblock terpolymer micellular vector could alter the DOX trafficking in cells. Hence, these suggest the pH-sensitive PMAgala-<i>b</i>-P­(MAA-<i>co</i>-MAChol)­s might be further exploited as a smart nanoplatform toward efficient antitumor drug delivery

Reversible Fluorescent Probe for Highly Selective and Sensitive Detection of Mercapto Biomolecules

A coumarin-derived complex, Hg2L2, was reported as a highly sensitive and selective probe for the detection of mercapto biomolecules in aqueous solution. The addition of Cys to a 99% aqueous solution of Hg2L2 resulted in rapid and remarkable fluorescence OFF–ON (emission at 525 nm) due to the ligand-exchange reaction of Cys with L coordinated to Hg2+. The increased fluorescence can be completely quenched by Hg2+ and recovered again by the subsequent addition of Cys. Such a fluorescence OFF–ON circle can be repeated at least 10 times by the alterative addition of Cys and Hg2+ to the solution of Hg2L2, indicating that it can be used as a convertible and reversible probe for the detection of Cys. The interconversion of Hg2L2 and L via the decomplexation/complexation by the modulation of Cys/Hg2+ was definitely verified from their crystal structures. Other competitive amino acids without a thiol group cannot induce any fluorescence changes, implying that Hg2L2 can selectively determine mercapto biomolecules. Using confocal fluorescence imaging, L/Hg2L2 as a pair of reversible probes can be further applied to track and monitor the self-detoxification process of Hg2+ ions in SYS5 cells

Reversible Fluorescent Probe for Highly Selective and Sensitive Detection of Mercapto Biomolecules

A coumarin-derived complex, Hg2L2, was reported as a highly sensitive and selective probe for the detection of mercapto biomolecules in aqueous solution. The addition of Cys to a 99% aqueous solution of Hg2L2 resulted in rapid and remarkable fluorescence OFF–ON (emission at 525 nm) due to the ligand-exchange reaction of Cys with L coordinated to Hg2+. The increased fluorescence can be completely quenched by Hg2+ and recovered again by the subsequent addition of Cys. Such a fluorescence OFF–ON circle can be repeated at least 10 times by the alterative addition of Cys and Hg2+ to the solution of Hg2L2, indicating that it can be used as a convertible and reversible probe for the detection of Cys. The interconversion of Hg2L2 and L via the decomplexation/complexation by the modulation of Cys/Hg2+ was definitely verified from their crystal structures. Other competitive amino acids without a thiol group cannot induce any fluorescence changes, implying that Hg2L2 can selectively determine mercapto biomolecules. Using confocal fluorescence imaging, L/Hg2L2 as a pair of reversible probes can be further applied to track and monitor the self-detoxification process of Hg2+ ions in SYS5 cells

Reversible Fluorescent Probe for Highly Selective and Sensitive Detection of Mercapto Biomolecules

A coumarin-derived complex, Hg2L2, was reported as a highly sensitive and selective probe for the detection of mercapto biomolecules in aqueous solution. The addition of Cys to a 99% aqueous solution of Hg2L2 resulted in rapid and remarkable fluorescence OFF–ON (emission at 525 nm) due to the ligand-exchange reaction of Cys with L coordinated to Hg2+. The increased fluorescence can be completely quenched by Hg2+ and recovered again by the subsequent addition of Cys. Such a fluorescence OFF–ON circle can be repeated at least 10 times by the alterative addition of Cys and Hg2+ to the solution of Hg2L2, indicating that it can be used as a convertible and reversible probe for the detection of Cys. The interconversion of Hg2L2 and L via the decomplexation/complexation by the modulation of Cys/Hg2+ was definitely verified from their crystal structures. Other competitive amino acids without a thiol group cannot induce any fluorescence changes, implying that Hg2L2 can selectively determine mercapto biomolecules. Using confocal fluorescence imaging, L/Hg2L2 as a pair of reversible probes can be further applied to track and monitor the self-detoxification process of Hg2+ ions in SYS5 cells

Honeycomb-Structured Films by Multifunctional Amphiphilic Biodegradable Copolymers: Surface Morphology Control and Biomedical Application as Scaffolds for Cell Growth

Recently, fabrication of functional porous polymer films with patterned surface structures at the scale from nanometer to micrometer has been attracting increasing interests in material science and nanobiotechnology. In this work, we present new preparation of two series of multifunctional amphiphilic copolymers and preparation of their microporous thin films on solid substrates. First, diblock dendritic poly(l-lysine)-b-poly(l-lactide)s and triblock dendritic poly(l-lysine)-b-poly(l-lactide)-b-dendritic poly(l-lysine)s (C1–C6) were synthesized through 4-dimethylaminopyridine (DMAP)-catalyzed living ring-opening polymerization of (l-)-lactide with (l-)-lysine dendron initiators, and their structures were characterized by nuclear magnetic resonance spectrometer (NMR), gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization Fourier-transformed mass spectra (MALDI-FTMS). Employing the breath-figure (BF) fabrication strategy, thin films of the synthesized amphiphiles (C1–C6) were drop-cast, and their surface topologies were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the effects of new amphiphile structure and drop-casting parameters of amphiphile concentration, humidity and temperature on self-assembly of ordered porous surface were studied. Furthermore, the influence of surface energy of drop-casting substrates was additionally investigated. With a human cervical epithelial carcinoma cell line (HeLa), cytotoxicity of the prepared honeycomb-structured films by new amphiphile C6 was evaluated by thiazoyl-blue-tetrazolium-bromide (MTT) assay, and HeLa cell growth behavior with microporous amphiphile films as the scaffolds was also examined. It was found that tunable micropore diameter sizes and well ordered surface topologies of BF films could be achieved for the new prepared amphiphiles, and utilization of the honeycomb-like microporous films as scaffolds indicated favorable enhancement in cell proliferation. Therefore, the honeycomb-structured films by these biocompatible multifunctional amphiphiles may provide new materials as 3D-scaffold materials for potential application in tissue engineering and regeneration

Colorimetric Test Kit for Cu²⁺ Detection

A coumarin-based colorimetric chemosensor 1 was designed and synthesized. It exhibits good sensitivity and selectivity for the copper cation over other cations such as Zn2+, Cd2+, Pb2+, Co2+, Fe2+, Ni2+, Ag+, and alkali and alkaline earth metal cations both in aqueous solution and on paper-made test kits. The change in color is very easily observed by the naked eye in the presence of Cu2+ cation, whereas other metal cations do not induce such a change. The quantitative detection of Cu2+ was preliminarily examined