Ultrathin BSA-Stabilized Black Phosphorous Nanoreactor Boosts Mild-Temperature Photothermal Therapy Through Modulation of Cellular Self-Defense Fate.

Mild-temperature photothermal therapy (mild-PTT, 42-45 °C) offers a higher level of biosafety. However, its therapeutic effects are compromised by the heat shock response (HSR), a cellular self-defense mechanism, which triggers the overexpression of heat shock proteins (HSPs) with the capacity of repairing the damaged tumor cells. Herein, this work fabricates a novel nanoreactor by incorporating up-conversion nanoparticles (UCNPs), chlorin e6 (Ce6), and glucose oxidase (GOx) onto the ultrathin black phosphorus nanosheet (BPNS) (denoted as GOx-BUC). This nanoreactor amplifies mild-PTT effects under irradiation with an 808 nm laser, modulating HSPs-mediated cellular self-defense fate. On one hand, upon irradiation with a 980 nm laser, UCNPs can transfer energy to excite Ce6, leading to the generation of ROS burst, which achieves indiscriminate damage to HSPs activity in deeper tumor tissues. On the other hand, GOx can consume glucose, thereby depleting the ATP energy supply and further suppressing HSPs expression. Consequently, GOx-BUC exhibits excellent anti-tumor efficacy under mild temperature in a human colorectal cancer mouse model, resulting in complete tumor inhibition with negligible side effects. This black phosphorous nanoreactor, featuring dual-track HSPs destruction functionality, introduces novel perspectives for enhancing mild-PTT effectiveness while maintaining high biosafety.

Ultrasensitive Detection of Cancer Biomarkers Using Photonic-Crystal-Enhanced Single-Molecule Imaging.

The rapid and sensitive quantification of low-abundance protein markers holds immense significance in early disease diagnosis and treatment. Single-molecule fluorescence imaging exhibits very high detection sensitivity and thus has great application potential in this area. The single-molecule signal, however, is often susceptible to interference from background noise due to its inherently weak intensity. A variety of signal amplification techniques based on cascading reactions have been developed to improve the signal-to-noise ratio of single-molecule imaging. Nevertheless, the operation of these methods is typically complicated and time-consuming, which limits the clinical application. Herein, we introduce an enzyme-free, photonic-crystal-based single-molecule (PC-SM) biochip for cost-effective, time-efficient, and ultrasensitive detection of disease markers. The PC-SM biochip can enhance the signal-to-noise ratio of single molecules by nearly 3-fold compared with unamplified samples, through coupling of the single-molecule photon energy with the optical band gap of the photonic crystal. We used the PC-SM biochip to detect the low-abundance leukemia inhibitory factor in the blood of pancreatic cancer patients and healthy people and achieved a detection limit of 2.0 pg/L and an AUC of 0.9067. The method exhibits exceptional sensitivity and specificity, showing great application potential in various clinical settings.

Regenerating Chemotherapeutics through Copper-Based Nanomedicine: Disrupting Protein Homeostasis for Enhanced Tumor Therapy.

The bis-(diethyldithiocarbamate)-copper (CuET), the disulfiram (DSF)-Cu complex, has exhibited noteworthy anti-tumor property. However, its efficacy is compromised due to the inadequate oxidative conditions and the limitation of bioavailable copper. Because CuET can inactivate valosin-containing protein (VCP), a bioinformatic pan-cancer analysis of VCP is first conducted in this study to identify CuET as a promising anticancer drug for diverse cancer types. Then, based on the drug action mechanism, a nanocomposite of CuET and copper oxide (CuO) is designed and fabricated utilizing bovine serum albumin (BSA) as the template (denoted as CuET-CuO@BSA, CCB). CCB manifests peroxidase (POD)-mimicking activity to oxidize the tumor endogenous H2O2 to generate reactive oxygen species (ROS), enhancing the chemotherapy effect of CuET. Furthermore, the cupric ions released after enzymatic reaction can regenerate CuET, which markedly perturbs intracellular protein homeostasis and induces apoptosis of tumor cells. Meanwhile, CCB triggers cuproptosis by inducing the aggregation of lipoylated proteins. The multifaceted action of CCB effectively inhibits tumor progression. Therefore, this study presents an innovative CuET therapeutic strategy that creates an oxidative microenvironment in situ and simultaneously self-supply copper source for CuET regeneration through the combination of CuO nanozyme with CuET, which holds promise for application of CuET for effective tumor therapy.

Recent Advances in Fluorescent Nanoparticles for Stimulated Emission Depletion Imaging.

Stimulated emission depletion (STED) microscopy, as a popular super-resolution imaging technique, has been widely used in bio-structure analysis and resolving the dynamics of biological processes beyond the diffraction limit. The performance of STED critically depends on the optical properties of the fluorescent probes. Ideally, the probe should process high brightness and good photostability, and exhibit a sensitive response to the depletion beam. Organic dyes and fluorescent proteins, as the most widely used STED probes, suffer from low brightness and exhibit rapid photobleaching under a high excitation power. Recently, luminescent nanoparticles (NPs) have emerged as promising fluorescent probes in biological imaging due to their high brightness and good photostability. STED imaging using various kinds of NPs, including quantum dots, polymer dots, carbon dots, aggregation-induced emission dots, etc., has been demonstrated. This review will comprehensively review recent advances in fluorescent NP-based STED probes, discuss their advantages and pitfalls, and outline the directions for future development.

In vitro modeling of skeletal muscle ischemia-reperfusion injury based on sphere differentiation culture from human pluripotent stem cells.

Skeletal muscle ischemia-reperfusion (IR) injury poses significant challenges due to its local and systemic complications. Traditional studies relying on two-dimensional (2D) cell culture or animal models often fall short of faithfully replicating the human in vivo environment, thereby impeding the translational process from animal research to clinical applications. Three-dimensional (3D) constructs, such as skeletal muscle spheroids with enhanced cell-cell interactions from human pluripotent stem cells (hPSCs) offer a promising alternative by partially mimicking human physiological cellular environment in vivo processes. This study aims to establish an innovative in vitro model, human skeletal muscle spheroids based on sphere differentiation from hPSCs, to investigate human skeletal muscle developmental processes and IR mechanisms within a controlled laboratory setting. By eticulously recapitulating embryonic myogenesis through paraxial mesodermal differentiation of neuro-mesodermal progenitors, we successfully established 3D skeletal muscle spheroids that mirror the dynamic colonization observed during human skeletal muscle development. Co-culturing human skeletal muscle spheroids with spinal cord spheroids facilitated the formation of neuromuscular junctions, providing functional relevance to skeletal muscle spheroids. Furthermore, through oxygen-glucose deprivation/re-oxygenation treatment, 3D skeletal muscle spheroids provide insights into the molecular events and pathogenesis of IR injury. The findings presented in this study significantly contribute to our understanding of skeletal muscle development and offer a robust platform for in vitro studies on skeletal muscle IR injury, holding potential applications in drug testing, therapeutic development, and personalized medicine within the realm of skeletal muscle-related pathologies.

Dual anti-angiogenic and anti-inflammatory action of tRNA-Cys-5-0007 in ocular vascular disease.

BACKGROUND: Intravitreal injections of angiogenesis inhibitors have proved efficacious in the majority of patients with ocular angiogenesis. However, one-fourth of all treated patients fail to derive benefits from intravitreal injections. tRNA-derived small RNA (tsRNA) emerges as a crucial class of non-coding RNA molecules, orchestrating key roles in the progression of human diseases by modulating multiple targets. Through our prior sequencing analyses and bioinformatics predictions, tRNA-Cys-5-0007 has shown as a potential regulator of ocular angiogenesis. This study endeavors to elucidate the precise role of tRNA-Cys-5-0007 in the context of ocular angiogenesis. METHODS: Quantitative reverse transcription PCR (qRT-PCR) assays were employed to detect tRNA-Cys-5-0007expression. EdU assays, sprouting assays, transwell assays, and Matrigel assays were conducted to elucidate the involvement of tRNA-Cys-5-0007 in endothelial angiogenic effects. STZ-induced diabetic model, OIR model, and laser-induced CNV model were utilized to replicate the pivotal features of ocular vascular diseases and evaluate the influence of tRNA-Cys-5-0007 on ocular angiogenesis and inflammatory responses. Bioinformatics analysis, luciferase activity assays, RNA pull-down assays, and in vitro studies were employed to elucidate the anti-angiogenic mechanism of tRNA-Cys-5-0007. Exosomal formulation was employed to enhance the synergistic anti-angiogenic and anti-inflammatory efficacy of tRNA-Cys-5-0007. RESULTS: tRNA-Cys-5-0007 expression was down-regulated under angiogenic conditions. Conversely, tRNA-Cys-5-0007 overexpression exhibited anti-angiogenic effects in retinal endothelial cells, as evidenced by reduced proliferation, sprouting, migration, and tube formation abilities. In diabetic, laser-induced CNV, and OIR models, tRNA-Cys-5-0007 overexpression led to decreased ocular vessel leakage, inhibited angiogenesis, and reduced ocular inflammation. Mechanistically, these effects were attributed to the targeting of vascular endothelial growth factor A (VEGFA) and TGF-ß1 by tRNA-Cys-5-0007. The utilization of an exosomal formulation further potentiated the synergistic anti-angiogenic and anti-inflammatory efficacy of tRNA-Cys-5-0007. CONCLUSIONS: Concurrent targeting of tRNA-Cys-5-0007 for anti-angiogenic and anti-inflammatory therapy holds promise for enhancing the effectiveness of current anti-angiogenic therapy.

Unraveling radiation-induced skeletal muscle damage: Insights from a 3D human skeletal muscle organoid model.

BACKGROUND: Three-dimensional (3D) organoids derived from human pluripotent stem cells (hPSCs) have revolutionized in vitro tissue modeling, offering a unique opportunity to replicate physiological tissue organization and functionality. This study investigates the impact of radiation on skeletal muscle response using an innovative in vitro human 3D skeletal muscle organoids (hSMOs) model derived from hPSCs. METHODS: The hSMOs model was established through a differentiation protocol faithfully recapitulating embryonic myogenesis and maturation via paraxial mesodermal differentiation of hPSCs. Key skeletal muscle characteristics were confirmed using immunofluorescent staining and RT-qPCR. Subsequently, the hSMOs were exposed to a clinically relevant dose of 2 Gy of radiation, and their response was analyzed using immunofluorescent staining and RNA-seq. RESULTS: The hSMO model faithfully recapitulated embryonic myogenesis and maturation, maintaining key skeletal muscle characteristics. Following exposure to 2 Gy of radiation, histopathological analysis revealed deficits in hSMOs expansion, differentiation, and repair response across various cell types at early (30 min) and intermediate (18 h) time points post-radiation. Immunofluorescent staining targeting γH2AX and 53BP1 demonstrated elevated levels of foci per cell, particularly in PAX7+ cells, during early and intermediate time points, with a distinct kinetic pattern showing a decrease at 72 h. RNA-seq data provided comprehensive insights into the DNA damage response within the hSMOs. CONCLUSIONS: Our findings highlight deficits in expansion, differentiation, and repair response in hSMOs following radiation exposure, enhancing our understanding of radiation effects on skeletal muscle and contributing to strategies for mitigating radiation-induced damage in this context.

Computer-assisted semi-rational design enhanced the enzymatic activity and protein stability of Proteinase K in calcium-free conditions.

Wild-type Proteinase K binds to two Ca2+ ions, which play an important role in regulating enzymaticactivity and maintaining protein stability. Therefore, a predetermined concentration of Ca2+ must be added during the use of Proteinase K, which increases its commercial cost. Herein, we addressed this challenge using a computational strategy to engineer a Proteinase K mutant that does not require Ca2+ and exhibits high enzymatic activity and protein stability. In the absence of Ca2+, the best mutant, MT24 (S17W-S176N-D260F), displayed an activity approximately 9.2-fold higher than that of wild-type Proteinase K. It also exhibited excellent protein stability, retaining 56.2 % of its enzymatic activity after storage at 4 °C for 5 days. The residual enzymatic activity was 65-fold higher than that of the wild-type Proteinase K under the same storage conditions. Structural analysis and molecular dynamics simulations suggest that the introduction of new hydrogen bond and π-π stacking at the Ca2+ binding sites due to the mutation may be the reasons for the increased enzymatic activity and stability of MT24.

Preparation and optimization of dummy molecularly imprinted polymer-based solid-phase extraction system for selective enrichment of p-toluene sulfonate esters genotoxic impurities.

Sulfonate esters, one class of genotoxic impurities (GTIs), have gained significant attention in recent years due to their potential to cause genetic mutations and cancer. In the current study, we employed the dummy template molecular imprinting technology with a dummy template molecule replacing the target molecule to establish a pretreatment method for samples containing p-toluene sulfonate esters. Through computer simulation and ultraviolet-visible spectroscopy analysis, the optimal functional monomer acrylamide and polymerization solvent chloroform were selected. Subsequently, a dummy template molecularly imprinted polymer (DMIP) was prepared by the precipitation polymerization method, and the polymer was characterized in morphology, particle size, and composition. The results of the adsorption and enrichment study demonstrated that the DMIP has high adsorption capability (Q = 7.88 mg/g) and favorable imprinting effects (IF = 1.37); Further, it could simultaneously adsorb three p-toluene sulfonate esters. The optimal adsorption conditions were obtained by conditional optimization of solid-phase extraction (SPE). A pH 7 solution was selected as the loading condition, the methanol/1 % phosphoric acid solution (20:80, v/v) was selected as the washing solution, and acetonitrile containing 10 % acetic acid in 6 mL was selected as the elution solvent. Finally, we determined methyl p-toluene sulfonate alkyl esters, ethyl p-toluene sulfonate alkyl esters, and isopropyl p-toluene sulfonate alkyl esters in tosufloxacin toluene sulfonate and capecitabine at the 10 ppm level (relative to 1 mg/mL active pharmaceutical ingredient (API) samples) by using DMIP-based SPE coupled with HPLC. This approach facilitated the selective enrichment of p-toluene sulfonate esters GTIs from complex API samples.

Solar-Driven Multistage Device Integrating Dropwise Condensation and Guided Water Transport for Efficient Freshwater and Salt Collection.

Interfacial solar vapor generation (ISVG) is an emerging technology to alleviate the global freshwater crisis. However, high-cost, low freshwater collection rate, and salt-blockage issues significantly hinder the practical application of solar-driven desalination devices based on ISVG. Herein, with a low-cost copper plate (CP), nonwoven fabric (NWF), and insulating ethylene-vinyl acetate foam (EVA foam), a multistage device is elaborately fabricated for highly efficient simultaneous freshwater and salt collection. In the designed solar-driven device, a superhydrophobic copper plate (SH-CP) serves as the condensation layer, facilitating rapid mass and heat transfer through dropwise condensation. Moreover, the hydrophilic NWF is designed with rational hydrophobic zones and specific high-salinity solution outlets (Design-NWF) to act as the water evaporation layer and facilitate directional salt collection. As a result, the multistage evaporator with eight stages exhibits a high water collection rate of 2.25 kg m-2 h-1 under 1 sun irradiation. In addition, the desalination device based on the eight-stage evaporator obtains a water collection rate of 13.44 kg m-2 and a salt collection rate of 1.77 kg m-2 per day under natural irradiation. More importantly, it can maintain a steady production for 15 days without obvious performance decay. This bifunctional multistage device provides a feasible and efficient approach for simultaneous desalination and solute collection.

Hyper strength, high sensitivity integrated wearable signal sensor based on non-covalent interaction of an ionic liquid and bacterial cellulose for human behavior monitoring.

Ion-sensing hydrogels exhibit electrical conductivity, softness, and mechanical and sensory properties akin to human tissue, rendering them an ideal material for mimicking human skin. In the realm of fabricating sensors for detecting human physiological activities, they present an ideal alternative to traditional rigid metal conductors. Nevertheless, achieving ionic hydrogels with outstanding tensile properties, toughness, ionic conductivity, and transport stability poses a significant challenge. This paper describes a simple method of forming a basic network by free radical polymerization of acrylamide, and then bacterial cellulose (BC) and 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) were introduced into the basic network. The polyhydrogen bonds and electrostatic interactions in the system gave the hydrogel notable tensile properties (3271 ± 37%), toughness (7.39 ± 0.13 MJ m-3), and high ultimate tensile stress (385.1 ± 7.2 kPa). In addition, the combination of BC and [EMIM]Cl collaboratively enhanced the mechanical properties and electrical conductivity. Ion sensing hydrogels have a wide operating strain range (≈1000%) and high sensitivity (gage factor (GF) = 11.85), and are therefore considered promising candidates for next-generation gel-based strain sensor platforms.

Single-cell transcriptomic sequencing identifies subcutaneous patient-derived xenograft recapitulated medulloblastoma.

BACKGROUND: Medulloblastoma (MB) is one of the most common malignant brain tumors that mainly affect children. Various approaches have been used to model MB to facilitate investigating tumorigenesis. This study aims to compare the recapitulation of MB between subcutaneous patient-derived xenograft (sPDX), intracranial patient-derived xenograft (iPDX), and genetically engineered mouse models (GEMM) at the single-cell level. METHODS: We obtained primary human sonic hedgehog (SHH) and group 3 (G3) MB samples from six patients. For each patient specimen, we developed two sPDX and iPDX models, respectively. Three Patch+/- GEMM models were also included for sequencing. Single-cell RNA sequencing was performed to compare gene expression profiles, cellular composition, and functional pathway enrichment. Bulk RNA-seq deconvolution was performed to compare cellular composition across models and human samples. RESULTS: Our results showed that the sPDX tumor model demonstrated the highest correlation to the overall transcriptomic profiles of primary human tumors at the single-cell level within the SHH and G3 subgroups, followed by the GEMM model and iPDX. The GEMM tumor model was able to recapitulate all subpopulations of tumor microenvironment (TME) cells that can be clustered in human SHH tumors, including a higher proportion of tumor-associated astrocytes and immune cells, and an additional cluster of vascular endothelia when compared to human SHH tumors. CONCLUSIONS: This study was the first to compare experimental models for MB at the single-cell level, providing value insights into model selection for different research purposes. sPDX and iPDX are suitable for drug testing and personalized therapy screenings, whereas GEMM models are valuable for investigating the interaction between tumor and TME cells.

Monodispersed and Monofunctionalized DNA-Caged Au Nano-Clusters with Enhanced Optical Properties for STED Imaging.

The performance of Stimulated Emission Depletion (STED) microscopy depends critically on the fluorescent probe. Ultrasmall Au nanoclusters (Au NCs) exhibit large Stokes shift, and good stimulated emission response, which are potentially useful for STED imaging. However, Au NCs are polydispersed in size, sensitive to the surrounding environment, and difficult to control surface functional group stoichiometry, which results in reduced density and high heterogeneity in the labeling of biological structures. Here, this limitation is overcome by developing a method to encapsulate ultrasmall Au NCs with DNA cages, which yielded monodispersed, and monofunctionalized Au NCs that are long-term stable. Moreover, the DNA-caging also greatly improved the fluorescence quantum yield and photostability of Au NCs. In STED imaging, the DNA-caged Au NCs yielded ≈40 nm spatial resolution and are able to resolve microtubule line shapes with good labeling density and homogeneity. In contrast, without caging, the Au NCs-DNA conjugates only achieved ≈55 nm resolution and yielded spotted, poorly resolved microtubule structures, due to the presence of aggregates. Overall, a method is developed to achieve precise surface functionalization and greatly improve the monodispersity, stability, as well as optical properties of Au NCs, providing a promising class of fluorescent probes for STED imaging.

Dual-responsive 3D DNA nanomachines cascaded hybridization chain reactions for novel self-powered flexible microRNA-detecting platform.

The microRNA-21 is closely related to chromatin remodeling and epigenetic regulation. In this work, an efficient double-response 3D DNA nanomachine (DRDN) was assembled by co-immobilizing two different lengths of hairpin DNA on the surface of gold nanoparticles (AuNPs) to capture microRNA-21 (miRNA-21), recycle miRNA-21, and trigger hybridization chain reactions (HCR). This work reports the fabrication of a laser-scribed graphene (LSG) electrode with excellent flexibility and electrical conductivity by laser-scribing commercial polyimide films (PI). The as-proposed self-powered biosensing platform presents significantly increased instantaneous current to in real-time monitor miRNA-21 by a capacitor. The biosensing platform exhibited highly sensitive detection of miRNA-21 with a detection limit of 0.142 fM in the range of 0.5 fM to 1 × 104 fM, and demonstrated high efficiency in the analysis of the tumor markers.

Single-Chain Conjugated Polymer Guests Confined inside Metal-Organic Frameworks (MOFs): Boosting the Detection and Degradation of a Sulfur Mustard Simulant.

Real-time detection and effective degradation of toxic gases have attracted considerable attention in environmental monitoring and human health. Here, we demonstrate a solvent-assisted dynamic assembly strategy to strongly enhance the detection and degradation performance for 2-chloroethyl ethyl sulfide (CEES, as a sulfur mustard simulant) via confinement of a conjugated polymer in metal-organic frameworks (MOFs). The conjugated polymer poly(9,9-di-n-octylfluorene-altbenzothiadiazole) (F8BT) is infiltrated into one-dimensional nanochannels of the Zr-based topological MOF NU-1000 in a single-chain manner, which is caused by the nanoconfinement effect and the steric hindrance between 9,9-dioctylfluorene units and benzothiadiazole units. The obtained F8BT⊂NU-1000 composites provide a high specific surface area and abundant active sites. Based on the cooperative effect of F8BT and NU-1000, rapid and sensitive detection of CEES has been achieved. Moreover, the F8BT⊂NU-1000 composites can selectively oxidize CEES into 2-chloroethyl ethyl sulfoxide (CEESO) under mild photooxidation conditions. Overall, this study opens a new avenue for the fabrication of conjugated polymer/MOF hybrid materials that show great potential for the sensitive detection and effective removal of hazardous chemicals.

Ultrasensitive Point-of-Care Detection of Protein Markers Using an Aptamer-CRISPR/Cas12a-Regulated Liquid Crystal Sensor (ALICS).

Despite extensive efforts, point-of-care testing (POCT) of protein markers with high sensitivity and specificity and at a low cost remains challenging. In this work, we developed an aptamer-CRISPR/Cas12a-regulated liquid crystal sensor (ALICS), which achieved ultrasensitive protein detection using a smartphone-coupled portable device. Specifically, a DNA probe that contained an aptamer sequence for the protein target and an activation sequence for the Cas12a-crRNA complex was prefixed on a substrate and was released in the presence of target. The activation sequence of the DNA probe then bound to the Cas12a-crRNA complex to activate the collateral cleavage reaction, producing a bright-to-dark optical change in a DNA-functionalized liquid crystal interface. The optical image was captured by a smartphone for quantification of the target concentration. For the two model proteins, SARS-CoV-2 nucleocapsid protein (N protein) and carcino-embryonic antigen (CEA), ALICS achieved detection limits of 0.4 and 20 pg/mL, respectively, which are higher than the typical sensitivity of the SARS-CoV-2 test and the clinical CEA test. In the clinical sample tests, ALICS also exhibited superior performances compared to those of the commercial ELISA and lateral flow test kits. Overall, ALICS represents an ultrasensitive and cost-effective platform for POCT, showing a great potential for pathogen detection and disease monitoring under resource-limited conditions.

Genome-Wide Identification, Evolution, and Expression Analysis of the WD40 Subfamily in Oryza Genus.

The WD40 superfamily is widely found in eukaryotes and has essential subunits that serve as scaffolds for protein complexes. WD40 proteins play important regulatory roles in plant development and physiological processes, such as transcription regulation and signal transduction; it is also involved in anthocyanin biosynthesis. In rice, only OsTTG1 was found to be associated with anthocyanin biosynthesis, and evolutionary analysis of the WD40 gene family in multiple species is less studied. Here, a genome-wide analysis of the subfamily belonging to WD40-TTG1 was performed in nine AA genome species: Oryza sativa ssp. japonica, Oryza sativa ssp. indica, Oryza rufipogon, Oryza glaberrima, Oryza meridionalis, Oryza barthii, Oryza glumaepatula, Oryza nivara, and Oryza longistaminata. In this study, 383 WD40 genes in the Oryza genus were identified, and they were classified into four groups by phylogenetic analysis, with most members in group C and group D. They were found to be unevenly distributed across 12 chromosomes. A total of 39 collinear gene pairs were identified in the Oryza genus, and all were segmental duplications. WD40s had similar expansion patterns in the Oryza genus. Ka/Ks analyses indicated that they had undergone mainly purifying selection during evolution. Furthermore, WD40s in the Oryza genus have similar evolutionary patterns, so Oryza sativa ssp. indica was used as a model species for further analysis. The cis-acting elements analysis showed that many genes were related to jasmonic acid and light response. Among them, OsiWD40-26/37/42 contained elements of flavonoid synthesis, and OsiWD40-15 had MYB binding sites, indicating that they might be related to anthocyanin synthesis. The expression profile analysis at different stages revealed that most OsiWD40s were expressed in leaves, roots, and panicles. The expression of OsiWD40s was further analyzed by qRT-PCR in 9311 (indica) under various hormone treatments and abiotic stresses. OsiWD40-24 was found to be responsive to both phytohormones and abiotic stresses, suggesting that it might play an important role in plant stress resistance. And many OsiWD40s might be more involved in cold stress tolerance. These findings contribute to a better understanding of the evolution of the WD40 subfamily. The analyzed candidate genes can be used for the exploration of practical applications in rice, such as cultivar culture for colored rice, stress tolerance varieties, and morphological marker development.

Supramolecular Responsive Chitosan Microcarriers for Cell Detachment Triggered by Adamantane.

Supramolecular responsive microcarriers based on chitosan microspheres were prepared and applied for nonenzymatic cell detachment. Briefly, chitosan microspheres (CSMs) were first prepared by an emulsion crosslinking approach, the surface of which was then modified with ß-cyclodextrin (ß-CD) by chemical grafting. Subsequently, gelatin was attached onto the surface of the CSMs via the host-guest interaction between ß-CD groups and aromatic residues in gelatin. The resultant microspheres were denoted CSM-g-CD-Gel. Due to their superior biocompatibility and gelatin niches, CSM-g-CD-Gel microspheres can be used as effective microcarriers for cell attachment and expansion. L-02, a human fetal hepatocyte line, was used to evaluate cell attachment and expansion with these microcarriers. After incubation for 48 h, the cells attached and expanded to cover the entire surface of microcarriers. Moreover, with the addition of adamantane (AD), cells can be detached from the microcarriers together with gelatin because of the competitive binding between ß-CD and AD. Overall, these supramolecular responsive microcarriers could effectively support cell expansion and achieve nonenzymatic cell detachment and may be potentially reusable with a new cycle of gelatin attachment and detachment.

Hyperbranched Polymer Dots with Strong Absorption and High Fluorescence Quantum Yield for In Vivo NIR-II Imaging.

In order to improve the fluorescence quantum yield (QY) of NIR-II-emitting nanoparticles, D-A-D fluorophores are typically linked to intramolecular rotatable units to reduce aggregation-induced quenching. However, incorporating such units often leads to a twisted molecular backbone, which affects the coupling within the D-A-D unit and, as a result, lowers the absorption. Here, we overcome this limitation by cross-linking the NIR-II fluorophores to form a 2D polymer network, which simultaneously achieves a high QY by well-controlled fluorophore separation and strong absorption by restricting intramolecular distortion. Using the strategy, we developed polymer dots with the highest NIR-II single-particle brightness among reported D-A-D-based nanoparticles and applied them for imaging of hindlimb vasculatures and tumors as well as fluorescence-guided tumor resection. The high brightness of the polymer dots offered exceptional image quality and excellent surgical results, showing a promising performance for these applications.

Novel Ultralow-Potential Electrochemiluminescence Aptasensor for the Highly Sensitive Detection of Zearalenone Using a Resonance Energy Transfer System.

An ultralow-potential electrochemiluminescence (ECL) aptasensor has been designed for zearalenone (ZEN) assay based on a resonance energy transfer (RET) system with SnS2 QDs/g-C3N4 as a novel luminophore and CuO/NH2-UiO-66 as a dual-quencher. SnS2 QDs were loaded onto g-C3N4 nanosheets and enhanced the ECL luminescence via strong synergistic effects under an ultralow potential. The UV-vis absorption spectrum of CuO/NH2-UiO-66 exhibits considerable overlap with the ECL emission spectrum of SnS2 QDs/g-C3N4, an important consideration for the RET process. In order to stimulate RET, the ZEN aptamer and complementary DNA are introduced for conjugation between the donor and the acceptor. With the binding interaction between ZEN by its aptamer, CuO/NH2-UiO-66 is removed from the electrode surface, resulting in the inhibition of the RET system and an increase in the ECL signal. Under optimal conditions, the as-prepared aptasensor quantified ZEN from 0.5 µg·mL-1 to 0.1 fg·mL-1 with a low limit of detection of 0.085 fg·mL-1, and it exhibited good stability, excellent specificity, high reproducibility, and desirable practicality. The sensing strategy provides a method for mycotoxins assay to monitor food safety.