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1.
NIR light responsive nanoplatforms hold great promise for on‐demand drug release in precision cancer medicine. However, currently available systems utilize “always‐on” photothermal transducers that lack target specificity, and thus inaccurately differentiate tumors from normal tissues. Developed here is a theranostic nanoplatform featuring H2S‐mediated in situ production of NIR photothermal agents for imaging‐guided and photocontrolled drug release. The system targets H2S‐rich cancers. This nanoplatform shows H2S‐activatable NIR‐II emission and NIR light controllable release of the drug Camptothecin‐11. Upon administering the system to HCT116 tumor‐bearing mice, the tumor is greatly suppressed with minimal side effects, arising from the synergy of the cancer‐specific and NIR light activated therapy. This theranostic nanoplatform thus sheds light on precision medicine with guidance through NIR‐II imaging.  相似文献   

2.
Near‐infrared (NIR) imaging techniques have attracted significant attention for biological and medicinal applications due to the ability of NIR to penetrate deeply into tissues. However, there are very few stable, activatable molecular probes that can utilize NIR light in the wavelength range beyond 800 nm. Herein, we report a new activatable NIR system for photoacoustic imaging based on tautomeric benziphthalocyanines (BPcs). We found that the existence of a free hydroxyl group is crucial for NIR absorption of BPcs. Synthesized water‐soluble hydroxy BPcs exhibited high photostability and no fluorescence, which are desirable features for photoacoustic imaging. We synthesized BPcs in which the free hydroxyl group was masked by an esterase‐labile or an H2O2‐labile group. The photoacoustic signals of these hydroxy‐masked BPcs were increased upon NIR excitation at 880 nm in the presence of esterase or H2O2, respectively. These are rare examples of activatable probes utilizing NIR light at around 900 nm.  相似文献   

3.
Near‐infrared (NIR) imaging techniques have attracted significant attention for biological and medicinal applications due to the ability of NIR to penetrate deeply into tissues. However, there are very few stable, activatable molecular probes that can utilize NIR light in the wavelength range beyond 800 nm. Herein, we report a new activatable NIR system for photoacoustic imaging based on tautomeric benziphthalocyanines (BPcs). We found that the existence of a free hydroxyl group is crucial for NIR absorption of BPcs. Synthesized water‐soluble hydroxy BPcs exhibited high photostability and no fluorescence, which are desirable features for photoacoustic imaging. We synthesized BPcs in which the free hydroxyl group was masked by an esterase‐labile or an H2O2‐labile group. The photoacoustic signals of these hydroxy‐masked BPcs were increased upon NIR excitation at 880 nm in the presence of esterase or H2O2, respectively. These are rare examples of activatable probes utilizing NIR light at around 900 nm.  相似文献   

4.
Near‐infrared (NIR) fluorescent dyes with favorable photophysical properties are highly useful for bioimaging, but such dyes are still rare. The development of a unique class of NIR dyes via modifying the rhodol scaffold with fused tetrahydroquinoxaline rings is described. These new dyes showed large Stokes shifts (>110 nm). Among them, WR3, WR4, WR5, and WR6 displayed high fluorescence quantum yields and excellent photostability in aqueous solutions. Moreover, their fluorescence properties were tunable by easy modifications on the phenolic hydroxy group. Based on WR6, two NIR fluorescent turn‐on probes, WSP‐NIR and SeSP‐NIR, were devised for the detection of H2S. The probe SeSP‐NIR was applied in visualizing intracellular H2S. These dyes are expected to be useful fluorophore scaffolds in the development of new NIR probes for bioimaging.  相似文献   

5.
Fluorescence‐guided cytoreductive surgery is one of the most promising approaches for facile elimination of tumors in situ, thereby improving prognosis. Reported herein is a simple strategy to construct a novel chainlike NIR‐II nanoprobe (APP‐Ag2S‐RGD) by self‐assembly of an amphiphilic peptide (APP) into a nanochain with subsequent chemical crosslinking of NIR‐II Ag2S QDs and the tumor‐targeting RGD peptide. This probe exhibits higher capability for cancer cell detection compared with that of RGD‐functionalized Ag2S QDs (Ag2S‐RGD) at the same concentration. Upon intraperitoneal injection, superior tumor‐to‐normal tissue signal ratio is achieved and non‐vascularized tiny tumor metastatic foci as small as about 0.2 mm in diameter could be facilely eliminated under NIR‐II fluorescent imaging guidance. These results clearly indicate the potential of this probe for fluorescence‐guided tumor staging, preoperative diagnosis, and intraoperative navigation.  相似文献   

6.
A two-photon fluorescence turn-on H2S probe GCTPOC–H2S based on a two-photon platform with a large cross-section, GCTPOC, and a sensitive H2S recognition site, dinitrophenyl ether was constructed. The probe GCTPOC–H2S exhibits desirable properties such as high sensitivity, high selectivity, functioning well at physiological pH and low cytotoxicity. In particular, the probe shows a 120-fold enhancement in the presence of Na2S (500 μM), which is larger than the reported two-photon fluorescent H2S probes. The large fluorescence enhancement of the two-photon probe GCTPOC–H2S renders it attractive for imaging H2S in living tissues with deep tissue penetration. Significantly, we have demonstrated that the probe GCTPOC–H2S is suitable for fluorescence imaging of H2S in living tissues with deep penetration by using two-photon microscopy. The further application of the two-photon probe for the investigation of biological functions and pathological roles of H2S in living systems is under progress.  相似文献   

7.
Hydrogen sulfide (H2S) is an important endogenous signaling molecule with a variety of biological functions. Development of fluorescent probes for highly selective and sensitive detection of H2S is necessary. We show here that dual‐reactable fluorescent H2S probes could react with higher selectivity than single‐reactable probes. One of the dual‐reactable probes gives more than 4000‐fold turn‐on response when reacting with H2S, the largest response among fluorescent H2S probes reported thus far. In addition, the probe could be used for high‐throughput enzymatic assays and for the detection of Cys‐induced H2S in cells and in zebrafish. These dual‐reactable probes hold potential for highly selective and sensitive detection of H2S in biological systems.  相似文献   

8.
Traumatic brain injury (TBI) is one of the most dangerous acute diseases resulting in high morbidity and mortality. Current methods remain limited with respect to early diagnosis and real‐time feedback on the pathological process. Herein, a targeted activatable fluorescent nanoprobe (V&A@Ag2S) in the second near‐infrared window (NIR‐II) is presented for in vivo optical imaging of TBI. Initially, the fluorescence of V&A@Ag2S is turned off owing to energy transfer from Ag2S to the A1094 chromophore. Upon intravenous injection, V&A@Ag2S quickly accumulates in the inflamed vascular endothelium of TBI based on VCAM1‐mediated endocytosis, after which the nanoprobe achieves rapid recovery of the NIR‐II fluorescence of Ag2S quantum dots (QDs) owing to the bleaching of A1094 by the prodromal biomarker of TBI, peroxynitrite (ONOO?). The nanoprobe offers high specificity, rapid response, and high sensitivity toward ONOO?, providing a convenient approach for in vivo early real‐time assessment of TBI.  相似文献   

9.
To realize sensing and labeling biomarkers is quite challenging in terms of designing multimodal imaging probes. In this study, we developed a novel β-galactosidase (β-gal) activated bimodal imaging probe that combines near-infrared (NIR) fluorescence and magnetic resonance imaging (MRI) to enable real-time visualization of activity in living organisms. Upon β-gal activation, Gal-Cy-Gd-1 exhibits a remarkable 42-fold increase in NIR fluorescence intensity at 717 nm, allowing covalent labeling of adjacent target enzymes or proteins and avoiding molecular escape to promote probe accumulation at the tumor site. This fluorescence reaction enhances the longitudinal relaxivity by approximately 1.9 times, facilitating high-resolution MRI. The unique features of Gal-Cy-Gd-1 enable real-time and precise visualization of β-gal activity in live tumor cells and mice. The probe's utilization aids in identifying in situ ovarian tumors, offering valuable assistance in the precise removal of tumor tissue during surgical procedures in mice. The fusion of NIR fluorescence and MRI activation through self-immobilizing target enzymes or proteins provides a robust approach for visualizing β-gal activity. Moreover, this approach sets the groundwork for developing other activatable bimodal probes, allowing real-time in vivo imaging of enzyme activity and localization.  相似文献   

10.
Activatable theranostic systems show potential for improved tumor diagnosis and therapy owing to high detection specificities, effective ablation, and minimal side‐effects. Herein, a tumor microenvironment (TME)‐activated NIR‐II nanotheranostic system (FEAD1) for precise diagnosis and treatment of peritoneal metastases is presented. FEAD1 was fabricated by self‐assembling the peptide Fmoc‐His, mercaptopropionic‐functionalized Ag2S quantum dots (MPA‐Ag2S QDs), the chemodrug doxorubicin (DOX), and NIR absorber A1094 into nanoparticles. We show that in healthy tissue, FEAD1 exists in an NIR‐II fluorescence “off” state, because of Ag2S QDs‐A1094 interactions, while DOX remains in stealth mode. Upon delivery of FEAD1 to the tumor, the acidic TME triggers its disassembly through breakage of the Fmoc‐His metal coordination and DOX hydrophobic interactions. Release of A1094 switches on Ag2S fluorescence, illuminating the tumor, accompanied by burst release of DOX within the tumor tissue, thereby achieving precise tumor theranostics. This TME‐activated theranostic strategy holds great promise for future clinical applications.  相似文献   

11.
Hydrogen sulfide (H2S) is connected with various physiological and pathological functions. However, understanding the important functions of H2S remains challenging, in part because of the lack of tools for detecting endogenous H2S. Herein, compounds Ratio‐H2S 1/2 are the first FRET‐based mitochondrial‐targetable dual‐excitation ratiometric fluorescent probes for H2S on the basis of H2S‐promoted thiolysis of dinitrophenyl ether. With the enhancement of H2S concentration, the excitation peak at λ≈402 nm of the phenolate form of the hydroxycoumarin unit drastically increases, whereas the excitation band centered at λ≈570 nm from rhodamine stays constant and can serve as a reference signal. Thus, the ratios of fluorescence intensities at λ=402 and 570 nm (I402/I570) exhibit a drastic change from 0.048 in the absence of H2S to 0.36 in the presence of 180 μM H2S; this is a 7.5‐fold variation in the excitation ratios. The favorable properties of the probe include the donor and acceptor excitation bands, which exhibit large excitation separations (up to 168 nm separation) and comparable excitation intensities, high sensitivity and selectivity, and function well at physiological pH. In addition, it is demonstrated that the probe can localize in the mitochondria and determine H2S in living cells. It is expected that this strategy will lead to the development of a wide range of mitochondria‐targetable dual‐excitation ratiometric probes for other analytes with outstanding spectral features, including large separations between the excitation wavelengths and comparable excitation intensities.  相似文献   

12.
The two signaling molecules H2S and H2O2 play key roles in maintaining intracellular redox homeostasis. The biological relationship between H2O2 and H2S remains largely unknown in redox biology. In this study, we rationally designed and synthesized single‐ and dual‐response fluorescent probes for detecting both H2O2 and H2S in living cells. The dual‐response probe was shown to be capable of mono‐ and dual‐detection of H2O2 and H2S selectively and sensitively. Detailed bioimaging studies based on the probes revealed that both exogenous and endogenous H2O2 could induce H2S biogenesis in living cells. By using gene‐knockdown techniques with bioimaging, the H2S biogenesis was found to be majorly cystathionine β‐synthase (CBS)‐dependent. Our finding shows the first direct evidence on the biological communication between H2O2 (ROS) and H2S (RSS) in vivo.  相似文献   

13.
Hydrogen sulfide (H2S) and hydrogen polysulfides (H2Sn, n>1) are endogenous regulators of many physiological processes. In order to better understand the symbiotic relationship and cellular cross‐talk between H2S and H2Sn, it is highly desirable to develop single fluorescent probes which enable dual‐channel discrimination between H2S and H2Sn. Herein, we report the rational design, synthesis, and evaluation of the first dual‐detection fluorescent probe DDP‐1 that can visualize H2S and H2Sn with different fluorescence signals. The probe showed high selectivity and sensitivity to H2S and H2Sn in aqueous media and in cells.  相似文献   

14.
Development of novel bioanalytical methods for monitoring of H2S is key toward understanding the physiological and pathological functions of this gasotransmitter in live organisms. A ruthenium(II)‐complex‐based luminescence probe, Ru‐MDB (MDB: 4’‐methyl‐[2,2’‐bipyridine]‐4‐yl)methyl 2‐((2,4‐dinitrophenyl)thio)benzoate), was developed by introducing a new H2S responsive masking moiety to a red‐emitting RuII luminophore. Cleavage of this masking group by a H2S‐triggered reaction leads to a luminescence “off–on” response. The long‐lived emissions of Ru‐MDB and its reaction product with H2S allowed quantitative detection of H2S in autofluorescence‐rich human sera and adult zebrafish organs using the time‐gated luminescence mode. Ru‐MDB exhibits red emission, a large Stokes shift, high specificity and sensitivity for H2S detection, and low cytotoxicity, which enables imaging and flow cytometry analysis of lysosomal H2S generation in live inflamed cells under drug stimulation. Monitoring of H2S in live Daphnia magna, zebrafish embryos, adult zebrafish, and mice, was conducted by in vivo imaging using Ru‐MDB as a probe.  相似文献   

15.
Enzyme activity in live cells is dynamically regulated by small‐molecule transmitters for maintaining normal physiological functions. A few probes have been devised to measure intracellular enzyme activities by fluorescent imaging, but the study of the regulation of enzyme activity via gasotransmitters in situ remains a long‐standing challenge. Herein, we report a three‐channel imaging correlation by a single dual‐reactive fluorescent probe to measure the dependence of phosphatase activity on the H2S level in cells. The two sites of the probe reactive to H2S and phosphatase individually produce blue and green fluorescent responses, respectively, and resonance energy transfer can be triggered by their coexistence. Fluorescent analysis based on the three‐channel imaging correlation shows that cells have an ideal level of H2S to promote phosphatase activity up to its maximum. Significantly, a slight deviation from this H2S level leads to a sharp decrease of phosphatase activity. The discovery further strengthens our understanding of the importance of H2S in cellular signaling and in various human diseases.  相似文献   

16.
Herein, we report the development of two fluorescent probes for the highly selective and sensitive detection of H2S. The probes take advantage of a CuII? cyclen complex, which acts as a reaction center for H2S and as a quencher of BODIPY (boron‐dipyrromethene)‐based fluorophores with emissions at 765 and 680 nm, respectively. These non‐fluorescent probes could only be turned on by the addition of H2S, and not by other potentially interfering biomolecules, including reactive oxygen species, cysteine, and glutathione. In a chemical system, both probes detected H2S with a detection limit of 80 nM . The probes were successfully used for the endogenous detection of H2S in HEK 293 cells, for measuring the H2S‐release activity of dietary organosulfides in MCF‐7 cells, and for the in vivo imaging of H2S in mice.  相似文献   

17.
《Analytical letters》2012,45(1):24-35
Abstract

A highly‐sensitive sequence‐selective DNA sensor based on HRP‐labeled probe to detect specific K‐ras gene which is highly associated with colorectal cancer has been reported. Capture probe modified with–SH was first chemically adsorbed on the gold electrode through self‐assembly. Then, the hybridization of a complementary nucleic acid (target DNA:K‐ras gene) and HRP labeled oligonucleotide detection probe occurred in a sandwich way. Finally, H2O2 electroreduction current catalyzed by HRP was measured amperometrically in the presence of hydroquinon as mediator. The sequence selectivity is double guaranteed by the complementary hybridization of target DNA with capture and detection probes. The experimental conditions were optimized. The linear range is 1.17×10?11~1.17×10?7 mol l?1 with a detection limit of 5.85×10?12 mol l?1. The electrode with capture probe can be reused after regeneration in boiling water.  相似文献   

18.
Hydrogen peroxide (H2O2) mediates the biology of wound healing, apoptosis, inflammation, etc. H2O2 has been fluorometrically imaged with protein‐ or small‐molecule‐based probes. However, only protein‐based probes have afforded temporal insights within seconds. Small‐molecule‐based electrophilic probes for H2O2 require many minutes for a sufficient response in biological systems. Here, we report a fluorogenic probe that selectively undergoes a [2,3]‐sigmatropic rearrangement (seleno‐Mislow‐Evans rearrangement) with H2O2, followed by acetal hydrolysis, to produce a green fluorescent molecule in seconds. Unlike other electrophilic probes, the current probe acts as a nucleophile. The fast kinetics enabled real‐time imaging of H2O2 produced in endothelial cells in 8 seconds (much earlier than previously shown) and H2O2 in a zebrafish wound healing model. This work may provide a platform for endogenous H2O2 detection in real time with chemical probes.  相似文献   

19.
Hydrogen sulfide (H2S) is an endogenously produced gaseous signaling molecule with multiple biological functions. To visualize the endogenous in situ production of H2S in real time, new coumarin‐ and boron‐dipyrromethene‐based fluorescent turn‐on probes were developed for fast sensing of H2S in aqueous buffer and in living cells. Introduction of a fluoro group in the ortho position of the aromatic azide can lead to a greater than twofold increase in the rate of reaction with H2S. On the basis of o‐fluorinated aromatic azides, fluorescent probes with high sensitivity and selectivity toward H2S over other biologically relevant species were designed and synthesized. The probes can be used to in situ to visualize exogenous H2S and D ‐cysteine‐dependent endogenously produced H2S in living cells, which makes them promising tools for potential applications in H2S biology.  相似文献   

20.
A ratiometric fluorescent probe for H2S was developed based on a coumarin– benzopyrylium platform. The ratiometric sensing is realized by a selective conversion of acyl azide to the corresponding amide, which subsequently undergoes an intramolecular spirocyclization to alter the large π-conjugated system of CB fluorophore. Compared with the traditional azide-based H2S probes, the proposed probe utilizes the acyl azide as the recognition moiety and exhibits a rapid response (∼1 min) towards H2S, which is superior to most of the azide-based H2S probes. Preliminary fluorescence imaging experiments show that probe 1 has potential to track H2S in living cells.  相似文献   

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