ABSTRACT
J-aggregation brings intriguing optical and electronic properties to molecular dyes and significantly expands their applicability across diverse domains, yet the challenge for rationally designing J-aggregating dyes persists. Herein, we developed a large number of J-aggregating dyes from scratch by progressively refining structure of a common heptamethine cyanine. J-aggregates with sharp spectral bands (full-width at half-maximum≤38â nm) are attained by introducing a branched structure featuring a benzyl and a trifluoroacetyl group at meso-position of dyes. Fine-tuning the benzyl group enables spectral regulation of J-aggregates. Analysis of single crystal data of nine dyes reveals a correlation between J-aggregation propensity and molecular arrangement within crystals. Some J-aggregates are successfully implemented in multiplexed optoacoustic and fluorescence imaging in animals. Notably, three-color multispectral optoacoustic tomography imaging with high spatiotemporal resolution is achieved, owing to the sharp and distinct absorption bands of the J-aggregates.
Subject(s)
Carbocyanines , Fluorescent Dyes , Optical Imaging , Photoacoustic Techniques , Photoacoustic Techniques/methods , Carbocyanines/chemistry , Animals , Fluorescent Dyes/chemistry , Mice , Molecular StructureABSTRACT
In the current study, an electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS) were employed to investigate the volatile flavor compounds (VFCs) of intense flavor beef tallow (L) and ordinary beef tallow (P). The study results indicate that an E-nose combined with an LDA and GC-IMS combined with an OPLS-DA can effectively distinguish between the two types of beef tallow. Compared with ordinary beef tallow, the E-nose sensors of intense flavor beef tallow have stronger response signals to sulfides, terpenes, and nitrogen oxides. A total of 22 compounds contribute to making the flavor of intense flavor beef tallow more typical and richer; in contrast, ethyl acetate was the main aroma-active compound found in the ordinary beef tallow. Sulfur-containing compounds and terpenoids might be the key substances that cause sensory flavor differences between the two types of beef tallow. In conclusion, the results of this study clarify the characteristics and differences of the two types of beef tallow and provide an enhanced understanding of the differences in the flavors of the two types of beef tallow.
ABSTRACT
As two major types of primary liver cancers, the tumor immune microenvironment (TIME) of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) have been well studied separately. However, a systemic assessment of the similarities and differences between the TIME of HCC and ICC is still lacking. In this study, we pictured a landscape of combined TIME of HCC and ICC by sequencing and integrating 41 single-cell RNA-seq samples from four different tissue types of both malignancies. We found that T cells in HCC tumors generally exhibit higher levels of immunosuppression and exhaustion than those in ICC tumors. Myeloid cells in HCC and ICC tumors also exhibit distinct phenotypes and may serve as a key factor driving the differences between their TIMEs. Besides, we identified a cluster of EGR1+ macrophages specifically enriched in HCC tumors. Together, our study provides new insights into cellular composition, states and interactions in the TIMEs of HCC and ICC, which could pave the way for the development of future therapeutic targets for liver cancers.
Subject(s)
Bile Duct Neoplasms , Carcinoma, Hepatocellular , Cholangiocarcinoma , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/pathology , Cholangiocarcinoma/genetics , Cholangiocarcinoma/pathology , Bile Ducts, Intrahepatic/pathology , Tumor MicroenvironmentABSTRACT
Aim of the Study: Brachial plexus block (BPB) is widely used for patients undergoing upper limb surgeries. Ropivacaine is the most commonly used local anesthetic for BPB. This study aimed to identify the optimal ropivacaine concentration for BPB in adult patients undergoing upper limb surgeries. Materials and Methods: PubMed, Embase, the Cochrane Library, and Web of Science were searched to identify randomized controlled trials (RCTs) that compared the effects of different concentrations of ropivacaine for BPB in adult patients undergoing upper limb surgeries. The primary outcomes were the onset time of sensory and motor block. RevMan 5.4 software was used for analysis. The GRADE approach was used to assess evidence quality. Results: Nine studies involving 504 patients were included. Compared to 0.5% ropivacaine, 0.75% ropivacaine shortened the onset time of sensory (WMD, -2.54; 95% CI; -4.84 to -0.24; <0.0001, moderate quality of evidence) and motor blockade (WMD, -2.46; 95% CI, -4.26 to -0.66; p = 0.01; moderate quality of evidence). However, 0.5% and 0.75% ropivacaine provided similar duration time of sensory (WMD, -0.07; 95% CI, -0.88 to 0.74; p = 0.81; high quality of evidence) and motor blockade (WMD, -0.24; 95% CI, -1.12 to 0.65; p = 0.55; high quality of evidence), as well as time to first request for oral analgesia (WMD, -1.57; 95% CI, -3.14 to 0.01; p = 0.5; moderate quality of evidence). Conclusion: Moderate-quality evidence suggested that, in terms of the onset time of sensory and motor blockade, 0.75% ropivacaine is a preferred concentration for BPB in upper limb surgeries. Systematic Review Registration: identifier CRD42023392145.
ABSTRACT
Human serum albumin (HSA) based drug delivery platforms that feature desirable biocompatibility and pharmacokinetic property are rapidly developed for tumor-targeted drug delivery. Even though various HSA-based platforms have been established, it is still of great significance to develop more efficient preparation technology to broaden the therapeutic applications of HSA-based nano-carriers. Here we report a bridging strategy that unfastens HSA to polypeptide chains and subsequently crosslinks these chains by a bridge-like molecule (BPY-Mal2) to afford the HSA reassemblies formulation (BPY@HSA) with enhanced loading capacity, endowing the BPY@HSA with uniformed size, high photothermal efficacy, and favorable therapeutic features. Both in vitro and in vivo studies demonstrate that the BPY@HSA presents higher delivery efficacy and more prominent photothermal therapeutic performance than that of the conventionally prepared formulation. The feasibility in preparation, stability, high photothermal conversion efficacy, and biocompatibility of BPY@HSA may facilitate it as an efficient photothermal agents (PTAs) for tumor photothermal therapy (PTT). This work provides a facile strategy to enhance the loading capacity of HSA-based crosslinking platforms in order to improve delivery efficacy and therapeutic effect.
Subject(s)
Nanoparticles , Neoplasms , Humans , Serum Albumin, Human/chemistry , Photothermal Therapy , Cell Line, Tumor , Neoplasms/therapy , Drug Delivery Systems , Nanoparticles/chemistry , PhototherapyABSTRACT
We report an azide-functionalized cobaloxime proton-reduction catalyst covalently tethered into the Wurster-type covalent organic frameworks (COFs). The cobaloxime-modified COF photocatalysts exhibit enhanced photocatalytic activity for hydrogen evolution reaction (HER) in alcohol-containing solution with no presence of a typical sacrificial agent. The best performing cobaloxime-modified COF hybrid catalyzes hydrogen production with an average HER rate up to 38â µmol h-1 in ethanol/phosphate buffer solution under 4â h illumination. Ultrafast transient optical spectroscopy characterizations and charge carrier analysis reveal that the alcohol contents functioning as hole scavengers could be oxidized by the photogenerated holes of COFs to form aldehydes and protons. The consumption of the photogenerated holes thus suppresses exciton recombination of COFs and improves the ratio of free electrons that were effectively utilized to drive catalytic reaction for HER. This work demonstrates a great potential of COF-catalyzed HER using alcohol solvents as hole scavengers and provides an example toward realizing the accessibility to the scope of reaction conditions and a greener route for energy conversion.
ABSTRACT
Polymerization in living systems has become an effective strategy to regulate cell functions and behavior. However, the requirement of high concentrations of monomers, the existence of complicated intracorporal interferences, and the demand for extra external stimulations hinder their further biological applications. Herein, a nanocompartment-confined strategy that provides a confined and secluded environment for monomer enrichment and isolation is developed to achieve high polymerization efficiency, reduce the interference from external environment, and realize broad-spectrum polymerizations in living systems. For exogenous photopolymerization, the light-mediated free-radical polymerization of sodium 4-styrenesulfonate induces a 2.7-fold increase in the reaction rate with the protection of a confined environment. For endogenous hydrogen peroxide-responsive polymerization, paminodiphenylamine hydrochloride embedded in a nanocompartment not only performs a 6.4-fold higher reaction rate than that of free monomers, but also activates an effective second near-infrared photoacoustic imaging-guided photothermal immunotherapy at tumor sites. This nanocompartment-confined strategy breaks the shackles of conventional polymerization, providing a universal platform for in vivo synthesis of polymers with diverse structures and functions.
Subject(s)
Hydrogen Peroxide , Immunotherapy , Polymerization , PolymersABSTRACT
The development of chiral covalentorganic framework catalysts (CCOFs) to synthesize enantiopure organic compounds is crucial and highly desirable in synthetic chemistry. Photocatalytic asymmetric reactions based on CCOFs are eco-friendly and sustainable while they are still elaborate. In this work, we report a general bottom-up strategy to successfully synthesize several photoactive CCOFX (X = 1-5 and 1-Boc). The photoactive porphyrin building blocks are selected as knots and various secondary-amine-based chiral catalytic centers are immobilized on the pore walls of CCOFX through a rational design of benzoimidazole linkers. The porphyrin units act as light-harvesting antennae to generate photo-induced charge carriers for the activation of bromide during the photocatalytic asymmetric alkylation of aldehydes. Meanwhile, various aldehydes are activated by the chiral secondary amine to form the target products with a high yield (up to 97%) and ee value (up to 93%). The results significantly expand the scope to predesign CCOF photocatalysts for visible-light-driven asymmetric catalysis.
ABSTRACT
Organic small-molecule contrast agents have attracted considerable attention in the field of multispectral optoacoustic imaging, but their weak optoacoustic performance resulted from relatively low extinction coefficient and poor water solubility restrains their widespread applications. Herein, we address these limitations by constructing supramolecular assemblies based on cucurbit[8]uril (CB[8]). Two dixanthene-based chromophores (DXP and DXBTZ) are synthesized as the model guest compounds, and then included in CB[8] to prepare host-guest complexes. The obtained DXP-CB[8] and DXBTZ-CB[8] display red-shifted and increased absorption as well as decreased fluorescence, thereby leading to a substantial enhancement in optoacoustic performance. Biological application potential of DXBTZ-CB[8] is investigated after co-assembly with chondroitin sulfate A (CSA). Benefiting from the excellent optoacoustic property of DXBTZ-CB[8] and the CD44-targeting feature of CSA, the formulated DXBTZ-CB[8]/CSA can effectively detect and diagnose subcutaneous tumors, orthotopic bladder tumors, lymphatic metastasis of tumors and ischemia/reperfusion-induced acute kidney injury in mouse models with multispectral optoacoustic imaging.
Subject(s)
Bridged-Ring Compounds , Macrocyclic Compounds , Mice , Animals , Water , Diagnostic ImagingABSTRACT
Cancer immunotherapy is revolutionizing oncology. The marriage of nanotechnology and immunotherapy offers a great opportunity to amplify antitumor immune response in a safe and effective manner. Here, electrochemically active Shewanella oneidensis MR-1 can be applied to produce FDA-approved Prussian blue nanoparticles on a large-scale. We present a mitochondria-targeting nanoplatform, MiBaMc, which consists of Prussian blue decorated bacteria membrane fragments having further modifications with chlorin e6 and triphenylphosphine. We find that MiBaMc specifically targets mitochondria and induces amplified photo-damages and immunogenic cell death of tumor cells under light irradiation. The released tumor antigens subsequently promote the maturation of dendritic cells in tumor-draining lymph nodes, eliciting T cell-mediated immune response. In two tumor-bearing mouse models using female mice, MiBaMc triggered phototherapy synergizes with anti-PDL1 blocking antibody for enhanced tumor inhibition. Collectively, the present study demonstrates biological precipitation synthetic strategy of targeted nanoparticles holds great potential for the preparation of microbial membrane-based nanoplatforms to boost antitumor immunity.
Subject(s)
Ferrocyanides , Immune Checkpoint Inhibitors , Female , Animals , Mice , Antibodies, Blocking , ImmunotherapyABSTRACT
To improve the gelling property of konjac gum (KGM) and enhance the application value of Abelmoschus manihot (L.) medic gum (AMG), a novel type of gel was prepared using KGM and AMG in this study. The effects of AMG content, heating temperature and salt ions on the characteristics of KGM/AMG composite gels were studied by Fourier transform infrared spectroscopy (FTIR), zeta potential, texture analysis and dynamic rheological behavior analysis. The results indicated that the AMG content, heating temperature and salt ions could affect the gel strength of KGM/AMG composite gels. Hardness, springiness, resilience, G', G* and η* of KGM/AMG composite gels increased when AMG content increased from 0 to 2.0 %, but they decreased when AMG increased from 2.0 % to 3.5 %. High-temperature treatment significantly enhanced the texture and rheological properties of KGM/AMG composite gels. The addition of salt ions reduced the zeta potential absolute value and weakened the texture and rheological properties of KGM/AMG composite gels. Furthermore, the KGM/AMG composite gels could be classified as non-covalent gels. The non-covalent linkages included hydrogen bonding and electrostatic interactions. These findings would help understand the properties and formation mechanism of KGM/AMG composite gels and help improve the application value of KGM and AMG.
Subject(s)
Abelmoschus , Amorphophallus , Amorphophallus/chemistry , Temperature , Heating , Mannans/chemistry , Gels/chemistry , Sodium Chloride , RheologyABSTRACT
The development of efficient photocatalysts for N2 fixation to produce NH3 under ambient conditions remains a great challenge. Since covalent organic frameworks (COFs) possess predesignable chemical structures, good crystallinity, and high porosity, it is highly significant to explore their potential for photocatalytic nitrogen conversion. Herein, we report a series of isostructural porphyrin-based COFs loaded with Au single atoms (COFX-Au, X = 1-5) for photocatalytic N2 fixation. The porphyrin building blocks act as the docking sites to immobilize Au single atoms as well as light-harvesting antennae. The microenvironment of the Au catalytic center is precisely tuned by controlling the functional groups at the proximal and distal positions of porphyrin units. As a result, COF1-Au decorated with strong electron-withdrawing groups exhibits a high activity toward NH3 production with rates of 333.0 ± 22.4 µmol g-1 h-1 and 37.0 ± 2.5 mmol gAu-1 h-1, which are 2.8- and 171-fold higher than that of COF4-Au decorated with electron-donating functional groups and a porphyrin-Au molecular catalyst, respectively. The NH3 production rates could be further increased to 427.9 ± 18.7 µmol g-1 h-1 and 61.1 ± 2.7 mmol gAu-1 h-1 under the catalysis of COF5-Au featuring two different kinds of strong electron-withdrawing groups. The structure-activity relationship analysis reveals that the introduction of electron-withdrawing groups facilitates the separation and transportation of photogenerated electrons within the entire framework. This work manifests that the structures and optoelectronic properties of COF-based photocatalysts can be finely tuned through a rational predesign at the molecular level, thus leading to superior NH3 evolution.
ABSTRACT
The present study used acetic acid, sodium hydroxide, and pepsin extract acid-soluble collagen (ASC), alkali-soluble collagen (ALSC), and pepsin-soluble collagen (PSC) from the bones of spent-hens, and the effects of three extraction methods on the characteristics, processing properties, antioxidant properties and acceptability of chicken bone collagen were compared. The results showed that the extraction rates of ASC, ALSC and PSC extracted from bones of spent-hens were 3.39%, 2.42% and 9.63%, respectively. The analysis of the amino acid composition, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR), and ultraviolet full spectrum showed that the collagen extracted by the three methods had typical collagen characteristics and stable triple-helix structure, but the triple helical structure of PSC is more stable, and acid and alkaline extraction seems to have adverse effects on the secondary structure of chicken bone collagen. Differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) scanning showed that PSC had higher thermal stability and more regular, loose, and porous microstructure. In addition, PSC has good processing properties, in vitro antioxidant activity, and organoleptic acceptability. Therefore, enzymatic hydrolysis was still one of the best methods to prepare collagen from bones of spent-hens, and enzyme-soluble collagen has wider application prospects in functional food and medicine and also provides an effective way for the high-value comprehensive utilization of waste chicken bone by-products.
ABSTRACT
Tailoring the morphology of nanocrystals is a promising way to enhance their catalytic performance. In most previous shape-controlled synthesis strategies, surfactants are inevitable due to their capability to stabilize different facets. However, the adsorbed surfactants block the intrinsic active sites of the nanocrystals, reducing their catalytic performance. For now, strategies to control the morphology without surfactants are still limited but necessary. Herein, a facile surfactant-free synthesis method is developed to regulate the morphology of Cu2O nanocrystals (e.g., solid nanocube, concave nanocube, cubic framework, branching nanocube, branching concave nanocube, and branching cubic framework) to enhance the electrocatalytic performance for the conversion of CO to n-propanol. Specifically, the Cu2O branching cubic framework (BCF-Cu2O), which is difficult to fabricate using previous surfactant-free methods, is fabricated by combining the concentration depletion effect and the oxidation etching process. More significantly, the BCF-Cu2O-derived catalyst (BCF) presents the highest n-propanol current density (-0.85 mA cm-2) at -0.45 V versus the reversible hydrogen electrode (VRHE), which is fivefold higher than that of the surfactant-coated Cu2O nanocube-derived catalyst (SFC, -0.17 mA cm-2). In terms of the n-propanol Faradaic efficiency in CO electroreduction, that of the BCF exhibits a 41% increase at -0.45 VRHE as compared with SFC. The high catalytic activity of the BCF that results from the clean surface and the coexistence of Cu(100) and Cu(110) in the lattice is well-supported by density functional theory calculations. Thus, this work presents an important paradigm for the facile fabrication of surface-clean nanocrystals with an enhanced application performance.
ABSTRACT
The effect of diet on skin aging has become an interesting research topic. Previous studies have mostly focused on the beneficial effects of collagen peptides derived from marine organisms on the aging skin when administered orally, while the beneficial effects of collagen peptides derived from poultry on aging skin have been rarely reported. In this study, collagen peptides were prepared from chicken bone by enzymatic hydrolysis, and the effect and mechanism of action of orally administered collagen peptides on alleviating skin aging induced by UV combined with D-galactose were investigated. The results showed that the chicken bone collagen had typical characteristics of collagen, and the chicken bone collagen peptides (CPs) were mainly small molecular peptides with a molecular weight of <3000 Da. In vivo experiments showed that CPs had a significant relieving effect on aging skin, indicated by the changes in the compostion and structure of the aging skin, improvement of skin antioxidant level, and inhibition of inflammation; the relieving effect was positively correlated with the dose of CPs. Further investigation showed that CPs first reduce the level of skin oxidation, inhibit the expression of the key transcription factor AP-1 (c-Jun and c-Fos), then activate the TGF-ß/Smad signaling pathway to promote collagen synthesis, inhibit the expression of MMP-1/3 to inhibit collagen degradation, and inhibit skin inflammation to alleviate skin aging in mice. Moreover, the skin transcriptome found that lysosomes activated after oral administration of CPs may be an important pathway for CPs in anti-skin aging, and is worthy of further research. These results suggested that CPs might be used as a functional anti-aging nutritional component.
Subject(s)
Skin Aging , Animals , Chickens/metabolism , Collagen/metabolism , Inflammation/metabolism , Lysosomes/metabolism , Mice , Peptides , Skin/metabolism , Ultraviolet RaysABSTRACT
BACKGROUND: Although intravenous dexamethasone prolongs the duration of analgesia for peripheral nerve blocks (PNB), the optimal dose of dexamethasone is not yet determined. This protocol aims to compare the analgesic effects of different doses of intravenous dexamethasone on PNB. METHODS: We will search PubMed, EMBASE, the Cochrane Central register of Controlled Trials (CENTRAL), and Web of Science to identify randomized controlled trials that compared the effects of different doses of intravenous dexamethasone for PNB. The duration of analgesia will be defined as the primary outcome. Secondary outcomes will include pain scores, analgesics consumption >48 hours, and the incidence of adverse effects. RevMan 5.3 software will be used for data analysis. RESULTS: This study will explore the optimal dose of intravenous dexamethasone for the prolongation of analgesia in PNB. CONCLUSION: The results of this study will provide evidence for the dose selection of intravenous dexamethasone in PNB.
Subject(s)
Dexamethasone , Nerve Block , Humans , Dexamethasone/therapeutic use , Nerve Block/methods , Pain, Postoperative/drug therapy , Systematic Reviews as Topic , Meta-Analysis as Topic , Peripheral NervesABSTRACT
Ionic conductive hydrogels have been widely applied in sensors, energy storage and soft electronics recently. However, most of the polyvinyl alcohol (PVA) based ionic hydrogels are mainly fabricated by soaking the hydrogels in high concentration electrolyte solution which can induce the waste of electrolyte and solvent. Herein, we have designed cellulose nanofibrils (CNF) and ZnSO4 reinforced PVA based hydrogels through a one-pot simple freezing-thawing method at low ZnSO4 concentration without any soaking process. Furthermore, the hydrogel with 0.4% CNF exhibited stress up to 0.79 MPa (242% strain) and high ionic conductivity of 0.32 S m-1 (0.07 M ZnSO4). Moreover, hydrogel sensor displayed high linear gauge factor 1.70 (0-200% strain), excellent stability, durability and reliability. The integrated hydrogel sensor also showed excellent sensor performance for human motion monitoring. This work provides a new prospect for the design of cellulose reinforced conductive hydrogels via a facile method.
Subject(s)
Cellulose/chemistry , Freezing , Nanofibers/chemistry , Polyvinyl Alcohol/chemistry , Wearable Electronic Devices , Carbohydrate Conformation , Cellulose/chemical synthesis , Electric Conductivity , Humans , Ions/chemistryABSTRACT
In 2020, the world's food crisis and health industry ushered into a real outbreak. On one side, there were natural disasters such as the novel coronavirus (2019-nCoV), desert locusts, floods, and droughts exacerbating the world food crisis, while on the other side, the social development and changes in lifestyles prompted the health industry to gradually shift from a traditional medical model to a new pattern of prevention, treatment, and nourishment. Therefore, this article reviews animal by-products collagen and derived peptide, as important components of innovative sustainable food systems. The review also considered the preparation, identification, and characterization of animal by-product collagen and collagen peptides as well as their impacts on the food system (including food processing, packaging, preservation, and functional foods). Finally, the application and research progress of animal by-product collagen and peptide in the food system along with the future development trend were discussed. This knowledge would be of great significance for a comprehensive understanding of animal by-product collagen and collagen peptides and would encourage the use of collagen in food processing, preservation, and functional foods.
Subject(s)
COVID-19 , Animals , COVID-19/prevention & control , Food Handling , Functional Food , Collagen , PeptidesABSTRACT
Developing high-quality NIR-II fluorophores (emission in 1000-1700 nm) for in vivo imaging is of great significance. Benzothiadiazole-core fluorophores are an important class of NIR-II dyes, yet ongoing limitations such as aggregation-caused quenching in aqueous milieu and non-activatable response are still major obstacles for their biological applications. Here, we devise an activatable nanoprobe to address these limitations. A molecular probe named BTPE-NO2 is synthesized by linking a benzothiadiazole core with two tetraphenylene groups serving as hydrophobic molecular rotors, followed by incorporating two nitrophenyloxoacetamide units at both ends of the core as recognition moieties and fluorescence quenchers. An FDA-approved amphiphilic polymer Pluronic F127 is then employed to encapsulate the molecular BTPE-NO2 to render the nanoprobe BTPE-NO2@F127. The pathological levels of H2O2 in the disease sites cleave the nitrophenyloxoacetamide groups and activate the probe, thereby generating strong fluorescent emission (950~1200 nm) and ultrasound signal for multi-mode imaging of inflammatory diseases. The nanoprobe can therefore function as a robust tool for detecting and imaging the disease sites with NIR-II fluorescent and multispectral optoacoustic tomography (MSOT) imaging. Moreover, the three-dimensional MSOT images can be obtained for visualizing and locating the disease foci.
Subject(s)
Chemical and Drug Induced Liver Injury/diagnostic imaging , Cystitis, Interstitial/diagnostic imaging , Hydrogen Peroxide/metabolism , Molecular Probes/metabolism , Reperfusion Injury/diagnostic imaging , Animals , Chemical and Drug Induced Liver Injury/metabolism , Cystitis, Interstitial/metabolism , Fluorescent Dyes/chemistry , Fluorescent Dyes/metabolism , Mice , Molecular Probes/chemistry , Optical Imaging , Photoacoustic Techniques , Reperfusion Injury/metabolism , Spectroscopy, Near-Infrared , UltrasonographyABSTRACT
Despite great efforts in the development of diverse nanomaterials, a general route to synthesize metal-free chalcogen quantum dots (QDs) is still lacking. Moreover, the modification of chalcogen QDs is a bottleneck that severely hinders their applications. Herein, we develop a facile method to construct different chalcogen QDs (including S QDs, Se QDs, and Te QDs) with the assistance of thiolates. In addition to stabilizing chalcogen QDs, the thiolates also endow the chalcogen QDs with favorable modifiability. Different from most dyes whose fluorescence is quenched after short-term light irradiation, the prepared chalcogen QDs have significantly enhanced fluorescence emission under continuous light irradiation. Taking advantage of the distinctive photoinduced fluorescence enhancement property, long-time cell imaging with superb performance is realized using the chalcogen QDs. It is envisioned that the chalcogen QDs show promising potential as fluorescent materials in different fields beyond bioimaging.