An ER-Horse Detonating Stress Cascade for Hepatocellular Carcinoma Nanotherapy.

Persisting and excessive endoplasmic reticulum stress (ERS) can evoke rapid cell apoptosis. Therapeutic interference of ERS signaling holds enormous potential for cancer nanotherapy. Herein, a hepatocellular carcinoma (HCC) cell-derived ER vesicle (ERV) encapsulating siGRP94, denoted as ER-horse, has been developed for precise HCC nanotherapy. Briefly, ER-horse, like the Trojan horse, was recognized via homotypic camouflage, imitated the physiological function of ER, and exogenously opened the Ca2+ channel. Consequently, the mandatory pouring-in of extracellular Ca2+ triggered the aggravated stress cascade (ERS and oxidative stress) and apoptosis pathway with the inhibition of unfolded protein response by siGRP94. Collectively, our findings provide a paradigm for potent HCC nanotherapy via ERS signaling interference and exploring therapeutic interference of physiological signal transduction pathways for precision cancer therapy.

Single-Step and Highly Sensitive Imaging of Exosomal PD-L1 through Aptamer-Activated Cascade Primer Exchange Reaction-Generated Branched DNA Nanostructures.

Exosomal PD-L1 plays a critical role in tumor progress and immunotherapy. However, accurately analyzing exosomal PD-L1 is greatly limited by the small-sized and free-floating nature of exosomes and the few proteins each exosome carries. We described herein a single-step and highly sensitive method, termed aptamer-triggered cascade primer exchange reaction (PER)-generated branched DNA nanostructures, for the quantification and imaging of exosomal PD-L1. The presence of exosomal PD-L1 converted the conformation of the recognition probe, accompanied by the exposure of primer 1. Then, primer 1 actuated the cascade PER, which generated branched DNA nanostructures containing numerous G-quadruplex for binding to thioflavin T (ThT) dye, leading to an amplified fluorescence signal. Profiting from directly growing branched DNA nanostructures on the surface of exosomes, the size of exosomes was enlarged and the movement of exosomes was limited, achieving the imaging of exosomal PD-L1 by conventional optical microscopy in a wash- and label-free fashion. Analyzing exosomal PD-L1 from serum samples of 15 cancer patients and 15 healthy volunteers demonstrated that this simple strategy could distinguish NSCLC patients from healthy donors with high clinical accuracy. Therefore, the developed assay has great potential as a transformative diagnostic toolkit for cancer detection and immunotherapy monitoring.

Hierarchical self-uncloaking CRISPR-Cas13a-customized RNA nanococoons for spatial-controlled genome editing and precise cancer therapy.

CRISPR-Cas13a holds enormous potential for developing precise RNA editing. However, spatial manipulation of CRISPR-Cas13a activity remains a daunting challenge for elaborately regulating localized RNase function. Here, we designed hierarchical self-uncloaking CRISPR-Cas13a-customized RNA nanococoons (RNCOs-D), featuring tumor-specific recognition and spatial-controlled activation of Cas13a, for precise cancer synergistic therapy. RNCOs-D consists of programmable RNA nanosponges (RNSs) capable of targeted delivery and caging chemotherapeutic drug, and nanocapsules (NCs) anchored on RNSs for cloaking Cas13a/crRNA ribonucleoprotein (Cas13a RNP) activity. The acidic endo/lysosomal microenvironment stimulates the outer decomposition of NCs with concomitant Cas13a RNP activity revitalization, while the inner disassembly through trans-cleavage of RNSs initiated by cis-recognition and cleavage of EGFR variant III (EGFRvIII) mRNA. RNCOs-D demonstrates the effective EGFRvIII mRNA silencing for synergistic therapy of glioblastoma cancer cells in vitro and in vivo. The engineering of RNSs, together with efficient Cas13a activity regulation, holds immense prospect for multimodal and synergistic cancer therapy.

Pu-erh Tea Restored Circadian Rhythm Disruption by Regulating Tryptophan Metabolism.

Pu-erh tea is a healthy beverage rich in phytochemicals, and its effect on the risk of inducing circadian rhythm disorders (CRD) is unclear. In this study, healthy mice were given water or 0.25% (w/v) Pu-erh tea for 7 weeks, followed by a 40 day disruption of the light/dark cycle. CRD caused dysregulation of neurotransmitter secretion and clock gene oscillations, intestinal inflammation, and disruption of intestinal microbes and metabolites. Pu-erh tea boosted the indole and 5-hydroxytryptamine pathways of tryptophan metabolism via the gut-liver-brain axis. Furthermore, its metabolites (e.g., IAA, Indole, 5-HT) enhanced hepatic glycolipid metabolism and down-regulated intestinal oxidative stress by improving the brain hormone release. Tryptophan metabolites and bile acids also promoted liver lipid metabolism and inhibited intestinal inflammation (MyD88/NF-κB) via the enterohepatic circulation. Collectively, 0.25% (w/v) Pu-erh tea has the potential to prevent CRD by promoting indole and 5-HT pathways of tryptophan metabolism and signaling interactions in the gut-liver-brain axis.

Multifunctional liposome for photoacoustic/ultrasound imaging-guided chemo/photothermal retinoblastoma therapy.

Retinoblastoma (RB) is a malignant intraocular neoplasm that occurs in children. Diagnosis and therapy are frequently delayed, often leading to metastasis, which necessitates effective imaging and treatment. In recent years, the use of nanoplatforms allowing both imaging and targeted treatment has attracted much attention. Herein, we report a novel nanoplatform folate-receptor (FR) targeted laser-activatable liposome termed FA-DOX-ICG-PFP@Lip, which is loaded with doxorubicin (DOX)/indocyanine green (ICG) and liquid perfluoropentane (PFP) for photoacoustic/ultrasound (PA/US) dual-modal imaging-guided chemo/photothermal RB therapy. The dual-modal imaging capability, photothermal conversion under laser irradiation, biocompatibility, and antitumor ability of these liposomes were appraised. The multifunctional liposome showed a good tumor targeting ability and was efficacious as a dual-modality contrast agent both in vivo and in vitro. When laser-irradiated, the liposome converted light energy to heat. This action caused immediate destruction of tumor cells, while simultaneously initiating PFP phase transformation to release DOX, resulting in both photothermal and chemotherapeutic antitumor effects. Notably, the FA-DOX-ICG-PFP@Lip showed good biocompatibility and no systemic toxicity was observed after laser irradiation in RB tumor-bearing mice. Hence, the FA-DOX-ICG-PFP@Lip shows great promise for dual-modal imaging-guided chemo/photothermal therapy, and may have significant value for diagnosing and treating RB.

Femtomolar and locus-specific detection of N6-methyladenine in DNA by integrating double-hindered replication and nucleic acid-functionalized MB@Zr-MOF.

In this study, a novel electrochemical biosensor was constructed for ultrasensitive and locus-specific detection of N6-Methyladenine (m6A) in DNA using double-hindered replication and nucleic acid-coated methylene blue (MB)@Zr-MOF. Based on the combination of m6A-impeded replication and AgI-mediated mismatch replication, this mode could effectively stop the extension of the strand once DNA polymerase encountered m6A site, which specifically distinguish the m6A site from natural A site in DNA. Also, Zr-MOF with high porosity and negative surface potential features was carefully chose to load cationic MB, resulting a stable and robust MB@Zr-MOF electrochemical tag. As a result, the developed biosensor exhibited a wide linear range from 1 fM to 1 nM with detection limit down to 0.89 fM. Profiting from the high sensitivity and selectivity, the biosensing strategy revealed good applicability, which had been demonstrated by quantitating m6A DNA at specific site in biological matrix. Thus, the biosensor provides a promising platform for locus-specific m6A DNA analysis.

A novel electrochemical biosensor based on peptidoglycan and platinum-nickel-copper nano-cube for rapid detection of Gram-positive bacteria.

A novel non-enzyme electrochemical biosensor for the rapid detection of Gram-positive bacteria has been constructed that relys on a stable and efficient combination between the peptidoglycan layer and platinum-nickel-copper nanocubes (Pt-Ni-Cu NCs). Briefly, bacteria were first captured by a specific antibody. Then, the electrochemical signal materials (Pt-Ni-Cu NCs) were bound to the bacteria peptidoglycan layer using specific structural and surface features. The rapid and sensitive bacterial detection was then achieved using intrinsic electrochemical characteristics and superoxidase-like activity of the Pt-Ni-Cu NCs. Moreover, the nature of peptidoglycan covering the whole bacteria provided the premise for signal amplification. Under optimal conditions, the electrochemical signal variation was proportional to the concentration of bacteria ranging from 1.5 × 102 to 1.5 × 108 CFU/mL with a detection limit of 42 CFU/mL using a working potential of - 0.4 V. This electrochemical biosensor has been successfully applied to detect bacteria concentrations in urine samples, and the recoveries range from 90.4 to 107%. The proposed biosensor could be applied for broad-spectrum detection of Gram-positive bacteria since most Gram-positive bacteria possess a thick peptidoglycan layer. The developed electrochemical biosensing strategy might be used as a potential tool for clinical pathogenic bacteria detection and point-of-care testing (POCT).

An Enzyme-Free "ON-OFF" Electrochemiluminescence Biosensor for Ultrasensitive Detection of PML/RARα based on Target-Switched DNA Nanotweezer.

Herein, an enzyme-free "ON-OFF" electrochemiluminescence (ECL) biosensor for ultrasensitive detection of fusion gene PML/RARα is constructed based on a simple target-switched DNA nanotweezer as hemin concentration controller. In this biosensor, the hemin concentration is primarily controlled by the conversion of "opened-closed" DNA nanotweezers and low concentration hemin is first used as electrochemically regenerable enhancer. In the absence of the target, the nanotweezers are in an opened state which lead to a low concentration of hemin in the solution, resulting in an enhanced Ru(bpy)32+ ECL signal. In the presence of the target, the closed nanotweezers absorbed onto the surface of electrode can capture the hemin, which achieves a high concentration of hemin and then quenches the ECL signal. The developed method achieves ultrasensitive detection of PML/RARα with a wide linear range from 1 fM to 1 nM and limit of detection as low as 0.125 fM. In addition, the ECL biosensor shows excellent specificity to the other subtypes of PML/RARα (subtype "S", "V"), "PML", and "RARα". Moreover, due to the high designable character of DNA nanotweezer, this method might provide a pragmatic Ru(bpy)32+ ECL platform for ultrasensitive detection of nucleic acid in the future.

Bis-three-way junction nanostructure and DNA machineries for ultrasensitive and specific detection of BCR/ABL fusion gene by chemiluminescence imaging.

A novel G-quadruplex DNAzyme-driven chemiluminescence (CL) imaging method has been developed for ultrasensitive and specific detection of BCR/ABL fusion gene based on bis-three-way junction (bis-3WJ) nanostructure and cascade DNA machineries. Bis-3WJ probes are designed logically to recognize BCR/ABL fusion gene, which forms the stable bis-3WJ nanostructure for the activation of polymerase/nicking enzyme machineries in cascade, resulting in synthesis of DNAzyme subunits. These DNAzyme subunits can form integrated DNAzyme by self-assembly to catalyze CL substrate, thus providing an amplified signal for the sensing events or outputs for AND logic operation. The imaging method achieved ultrasensitive detection of BCR/ABL fusion gene with a low detection limit down to 23 fM. And this method exhibited wide linear ranges over seven orders of magnitude and excellent discrimination ability toward target. In addition, an acceptable recovery was obtained in complex matrix. It is notable that this biosensing strategy possesses merits of homogenous, isothermal and label-free assay system. Therefore, these merits endow the developed imaging method with a potential tool for CML diagnosis.

Determination of oxytetracycline by flow injection with chemiluminescence detection.

A flow-injection chemiluminescent method for the determination of oxytetracycline was developed. The method is based on an enhancement by oxytetracycline of the chemiluminescence light emission of tris(2,2'-bipyridine) ruthenium (II), generated by the continuous oxidation of tris(2,2'-bipyridine) ruthenium (II) by cerium (IV) sulphate in sulphuric acid. Under the optimum conditions, the calibration curve was linear over the range 1.0 x 10(-7)-1.0 x 10(-5) g/mL for oxytetracycline with the linear equation: DeltaINT = 148.77 x C + 0.6637 (R2 = 0.9994). The detection limit was 4.52 x 10(-8) g/mL. The proposed method was also successfully used to determine oxytetracycline in pharmaceutical formulations. The mean recovery of determination of oxytetracycline was 92.73%. A mechanism for the chemiluminescence enhancement by oxytetracycline of tris(2,2'-bipyridine)-ruthenium (II) and cerium (IV) sulphate system is also proposed.