Cascade CRISPR/Cas12a and DSN for the electrochemical biosensing of miR-1246 in BC-derived exosomes.

MiR-1246 in breast cancer-derived exosomes was a promising biomarker for early diagnosis of breast cancer(BC). However, the low abundance, high homology and complex background interference make the accurate quantitative detection of miR-1246 facing great challenges. In this study, we developed an electrochemical biosensor based on the subtly combined of CRISPR/Cas12a, double-stranded specific nuclease(DSN) and magnetic nanoparticles(MNPs) for the detection of miR-1246 in BC-derived exosomes. Ascribed to the good synergistic effect of DSN, Cas12a and MNPs, the developed electrochemical biosensor exhibited excellent performance with the linear range from 500 aM to 5 pM, and the detection limit as low down to about 50 aM. The target-specific triggered enzyme-digest activity of DSN and Cas12a system, as well as the powerful separation ability of MNPs ensure the high specificity of developed electrochemical biosensor which can distinguish single base mismatches. In addition, the developed electrochemical biosensor has been successfully applied to detect miR-1246 in blood-derived exosomes and realize distinguishing the BC patients from the healthy individuals. It is expected that the well-designed biosensing platform will open up new avenues for clinical liquid biopsy and early screening of breast cancer, as well as provide deeper insights into clinical oncology treatment.

Rare Earth Nanoprobes for Targeted Delineation of Triple Negative Breast Cancer and Enhancement of Radioimmunotherapy.

Radiotherapy demonstrates a synergistic effect with immunotherapy by inducing a transformation of "immune cold" tumors into "immune hot" tumors in triple negative breast cancer (TNBC). Nevertheless, the effectiveness of immunotherapy is constrained by low expression of tumor-exposed antigens, inadequate inflammation, and insufficient tumor infiltrating lymphocyte (TILs). To address this predicament, novel lutecium-based rare earth nanoparticles (RENPs) are synthesized with the aim of amplifying radiation effect and tumor immune response. The nanoprobe is characterized by neodymium-based down-conversion fluorescence, demonstrating robust photostability, biocompatibility, and targetability. The conjugation of RENPs with a CXCR4 targeted drug enables precise delineation of breast tumors using a near-infrared imaging system and improves radiation efficacy via lutetium-based radio-sensitizer in vivo. Furthermore, the study shows a notable enhancement of immune response through the induction of immunogenic cell death and recruitment of TILs, resulting in the inhibition of tumor progression both in vitro and in vivo models following the administration of nanoparticles. Hence, the novel multifunctional nanoprobes incorporating various lanthanide elements offer the potential for imaging-guided tumor delineation, radio-sensitization, and immune activation post-radiation, thus presenting an efficient radio-immunotherapeutic approach for TNBC.

Nanozymes for the Therapeutic Treatment of Diabetic Foot Ulcers.

Diabetic foot ulcers (DFU) are chronic, refractory wounds caused by diabetic neuropathy, vascular disease, and bacterial infection, and have become one of the most serious and persistent complications of diabetes mellitus because of their high incidence and difficulty in healing. Its malignancy results from a complex microenvironment that includes a series of unfriendly physiological states secondary to hyperglycemia, such as recurrent infections, excessive oxidative stress, persistent inflammation, and ischemia and hypoxia. However, current common clinical treatments, such as antibiotic therapy, insulin therapy, surgical debridement, and conventional wound dressings all have drawbacks, and suboptimal outcomes exacerbate the financial and physical burdens of diabetic patients. Therefore, development of new, effective and affordable treatments for DFU represents a top priority to improve the quality of life of diabetic patients. In recent years, nanozymes-based diabetic wound therapy systems have been attracting extensive interest by integrating the unique advantages of nanomaterials and natural enzymes. Compared with natural enzymes, nanozymes possess more stable catalytic activity, lower production cost and greater maneuverability. Remarkably, many nanozymes possess multienzyme activities that can cascade multiple enzyme-catalyzed reactions simultaneously throughout the recovery process of DFU. Additionally, their favorable photothermal-acoustic properties can be exploited for further enhancement of the therapeutic effects. In this review we first describe the characteristic pathological microenvironment of DFU, then discuss the therapeutic mechanisms and applications of nanozymes in DFU healing, and finally, highlight the challenges and perspectives of nanozyme development for DFU treatment.

A portable transistor immunosensor for fast identification of porcine epidemic diarrhea virus.

Widespread distribution of porcine epidemic diarrhea virus (PEDV) has led to catastrophic losses to the global pig farming industry. As a result, there is an urgent need for rapid, sensitive and accurate tests for PEDV to enable timely and effective interventions. In the present study, we develop and validate a floating gate carbon nanotubes field-effect transistor (FG CNT-FET)-based portable immunosensor for rapid identification of PEDV in a sensitive and accurate manner. To improve the affinity, a unique PEDV spike protein-specific monoclonal antibody is prepared by purification, and subsequently modified on FG CNT-FET sensor to recognize PEDV. The developed FET biosensor enables highly sensitive detection (LoD: 8.1 fg/mL and 100.14 TCID50/mL for recombinant spike proteins and PEDV, respectively), as well as satisfactory specificity. Notably, an integrated portable platform consisting of a pluggable FG CNT-FET chip and a portable device can discriminate PEDV positive from negative samples and even identify PEDV and porcine deltacoronavirus within 1 min with 100% accuracy. The portable sensing platform offers the capability to quickly, sensitively and accurately identify PEDV, which further points to a possibility of point of care (POC) applications of large-scale surveillance in pig breeding facilities.

Pt,P-codoped carbon nitride nanoenzymes for fluorescence and colorimetric dual-mode detection of cholesterol.

Cholesterol is an important lipid compound found in a variety of foods, and its level in human blood is closely related to human health. Therefore, development of rapid and accurate POCT (point-of-care testing) methods for cholesterol detection is crucial for assessing food quality and early diagnosis of diseases, in particular, in a resource-limited environment. In this study, a smartphone-assisted colorimetric biosensor is constructed based on platinum,phosphorus-codoped carbon nitride (PtCNP2) for the rapid detection of cholesterol. Phosphorus-doped carbon nitride is prepared by thermal annealing of urea and NH4PF6, into which platinum is atomically dispersed by thermal refluxing. The obtained PtCNP2 exhibits an excellent peroxidase-like activity under physiological pH, whereby colorless o-phenylenediamine (OPD) is oxidized to colored 2,3-diaminophenazine (DAP) in the presence of hydrogen peroxide (H2O2), which can be produced during the oxidation of cholesterol by cholesterol oxidase. A smartphone-assisted visual sensing system is then constructed based on the color recognition software, and rapid on-site detection of cholesterol is achieved by reading the RGB values. Meanwhile, the generated DAP shows an apparent fluorescence signal and can realize highly sensitive detection of cholesterol by the change of the fluorescence signal intensity. Such a cholesterol sensor exhibits a wide linear detection range of 0.5-600 µg mL-1 and a low detection limit of 59 ng mL-1. The practicality of the sensor is successfully demonstrated in the rapid detection of cholesterol in serum and food.

Emerging Drug Delivery Vectors: Engineering of Plant-Derived Nanovesicles and Their Applications in Biomedicine.

Extracellular vesicles can transmit intercellular information and transport biomolecules to recipient cells during various pathophysiological processes in the organism. Animal cell exosomes have been identified as potential nanodrugs delivery vehicles, yet they have some shortcomings such as high immunogenicity, high cytotoxicity, and complicated preparation procedures. In addition to exosomes, plant-derived extracellular vesicles (PDVs), which carry a variety of active substances, are another promising nano-transport vehicles emerging in recent years due to their stable physicochemical properties, wide source, and low cost. This work briefly introduces the collection and characterization of PDVs, then focuses on the application of PDVs as natural or engineered drug carriers in biomedicine, and finally discusses the development and challenges of PDVs in future applications.

A Drug Molecule-Modified Graphene Field-Effect Transistor Nanosensor for Rapid, Label-Free, and Ultrasensitive Detection of Estrogen Receptor α Protein.

Estrogen receptor α (ERα) is an important biomarker in breast cancer diagnosis and treatment. Sensitive and accurate detection of ERα protein expression is crucial in guiding selection of an appropriate therapeutic strategy to improve the effectiveness and prognosis of breast cancer treatment. Herein, we report a liquid-gated graphene field-effect transistor (FET) biosensor that enables rapid, sensitive, and label-free detection of the ERα protein by employing a novel drug molecule as a capture probe. The drug molecule was synthesized and subsequently immobilized onto the sensing surface of the fabricated graphene FET, which was able to distinguish the ERα-positive from the ERα-negative protein. The developed sensor not only demonstrated a low detection limit (LOD: 2.62 fM) but also achieved a fast response to ERα protein samples within 30 min. Moreover, depending on the relationship between the change of dirac point and the ERα protein concentrations, the dissociation constant (Kd) was estimated to be 7.35 ± 0.06 pM, indicating that the drug probe-modified graphene FET had a good affinity with ERα protein. The nanosensor was able to analyze ERα proteins from 36 cell samples lysates. These results show that the graphene FET sensor was able to differentiate between ERα-positive and ERα-negative cells, indicating a promising biosensor for the ultrasensitive and rapid detection of ERα protein without antibody labeling.

Plug-and-play smart transistor bio-chips implementing point-of-care diagnosis of AMI with modified CRISPR/Cas12a system.

The point-of-care diagnosis of acute myocardial infarction (AMI), an extremely lethal disease with only a few hours of golden rescue time, is significant and urgently required. Here, we describe a plug-and-play carbon nanotube field effect transistor (CNT-FET) bio-chip supported with a smart portable readout for ultrasensitive and on-site testing of cardiac troponin I (cTnI), which is one of the most specific and valuable biomarkers of AMI. A modified clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system, featuring the G-triplex structured reporter, was first combined with the CNT-FET to realize non-nucleic acid detection. Such a unique CNT-FET biosensor achieved the high sensitivity (LOD: 0.33 fg/mL), which is expected to give timely warning in the early stage of myocardial injury. In addition, a bilayer gate dielectric consisting of Y2O3/HfO2, employed into the passivation process, enabled the high environmental stability and repeatability of CNT-FET. More importantly, the homemade compact chip readout forged a field-deployable cTnI analytical tool, realizing "plasma-to-answer" performance for AMI patients in point-of-care testing scenarios. The developed technology holds promise to help doctors make clinical decisions faster, especially in remote areas.

Notch3 restricts metastasis of breast cancers through regulation of the JAK/STAT5A signaling pathway.

PURPOSE: To explore the potential role of signal transducer and activator of transcription 5A (STAT5A) in the metastasis of breast cancer, and its mechanism of regulation underlying. METHODS AND RESULTS: TCGA datasets were used to evaluate the expression of STAT5A in normal and different cancerous tissues through TIMER2.0, indicating that STAT5A level was decreased in breast cancer tissues compared with normal ones. Gene Set Enrichment Analysis predicted that STAT5A was associated with the activation of immune cells and cell cycle process. We further demonstrated that the infiltration of immune cells was positively associated with STAT5A level. Influorescence staining revealed the expression and distribution of F-actin was regulated by STAT5A, while colony formation assay, wound healing and transwell assays predicted the inhibitory role of STAT5A in the colony formation, migratory and invasive abilities in breast cancer cells. In addition, overexpression of the Notch3 intracellular domain (N3ICD), the active form of Notch3, resulted in the increased expression of STAT5A. Conversely, silencing of Notch3 expression by siNotch3 decreased STAT5A expression, supporting that STAT5A expression is positively associated with Notch3 in human breast cancer cell lines and breast cancer tissues. Mechanistically, chromatin immunoprecipitation showed that Notch3 was directly bound to the STAT5A promoter and induced the expression of STAT5A. Moreover, overexpressing STAT5A partially reversed the enhanced mobility of breast cancer cells following Notch3 silencing. Low expression of Notch3 and STAT5A predicted poorer prognosis of patients with breast cancer. CONCLUSION: The present study demonstrates that Notch3 inhibits metastasis in breast cancer through inducing transcriptionally STAT5A, which was associated with tumor-infiltrating immune cells, providing a novel strategy to treat breast cancer.

Genome-wide analysis of transposable elements and satellite DNA in Humulus scandens, a dioecious plant with XX/XY1Y2 chromosomes.

Transposable elements (TEs) and satellite DNAs, two major categories of repetitive sequences, are expected to accumulate in non-recombining genome regions, including sex-linked regions, and contribute to sex chromosome evolution. The dioecious plant, Humulus scandens, can be used for studying the evolution of the XX/XY1Y2 sex chromosomes. In this study, we thoroughly examined the repetitive components of male and female H. scandens using next-generation sequencing data followed by bioinformatics analysis and florescence in situ hybridization (FISH). The H. scandens genome has a high overall repetitive sequence composition, 68.30% in the female and 66.78% in the male genome, with abundant long terminal repeat (LTR) retrotransposons (RTs), including more Ty3/Gypsy than Ty1/Copia elements, particularly two Ty3/Gypsy lineages, Tekay and Retand. Most LTR-RT lineages were found dispersed across the chromosomes, though CRM and Athila elements were predominately found within the centromeres and the pericentromeric regions. The Athila elements also showed clearly higher FISH signal intensities in the Y1 and Y2 chromosomes than in the X or autosomes. Three novel satellite DNAs were specifically distributed in the centromeric and/or telomeric regions, with markedly different distributions on the X, Y1, and Y2 chromosomes. Combined with FISH using satellite DNAs to stain chromosomes during meiotic diakinesis, we determined the synapsis pattern and distinguish pseudoautosomal regions (PARs). The results indicate that the XY1Y2 sex chromosomes of H. scandens might have originated from a centric fission event. This study improves our understanding of the repetitive sequence organization of H. scandens genome and provides a basis for further analysis of their chromosome evolution process.

Integrated FET sensing microsystem for specific detection of pancreatic cancer exosomal miRNA10b.

Tumor-derived exosome (TD-Ex) serves as a crucial early diagnostic biomarker of pancreatic cancer (PC). However, accurate identification of TD-Ex from PC is still a challenging work. In this paper, a detection microsystem that integrates magnetic separation and FET biosensor is developed, which is capable of selectively separating TD-Ex of PC from the plasma and detecting exosomal miRNA10b in a sensitive and specific manner. The magnetic beads were functionalized with dual antibody (GPC-1 antibody and EpCAM antibody), enabling selective recognition and capture of PC-derived exosomes. On the other hand, a peptide nucleic acid (PNA)- functionalized reduced graphene oxide field-effect transistor (RGO FET) biosensor was subsequently utilized to detect the exosomal miRNA10b, which is highly expressed in PC- derived exosomes. This system could achieve a low detection limit down to 78 fM, and selectively identify miRNA10b from single-base mismatched miRNA. In addition, 40 clinical plasma samples were tested with this microsystem, and the results indicate that it could effectively distinguish PC patients from healthy individuals. The assay combines specific capture and enrichment of PC-derived exosomes with sensitive and selective detection of exosomal miRNA, showing its potential to be used as an effective scheme for PC early diagnosis.

Methylation of ESR1 promoter induced by SNAI2-DNMT3B complex promotes epithelial-mesenchymal transition and correlates with poor prognosis in ERα-positive breast cancers.

Estrogen receptor α (ERα) serves as an essential therapeutic predictor for breast cancer (BC) patients and is regulated by epigenetic modification. Abnormal methylation of cytosine phosphoric acid guanine islands in the estrogen receptor 1 (ESR1) gene promoter could silence or decrease ERα expression. In ERα-negative BC, we previously found snail family transcriptional repressor 2 (SNAI2), a zinc-finger transcriptional factor, recruited lysine-specific demethylase 1 to the promoter to transcriptionally suppress ERα expression by demethylating histone H3 lysine 4 dimethylation (H3K4me2). However, the role of SNAI2 in ERα-positive BC remains elusive. In this study, we observed a positive correlation between SNAI2 and ESR1 methylation, and SNAI2 promoted ESR1 methylation by recruiting DNA methyltransferase 3 beta (DNMT3B) rather than DNA methyltransferase 1 (DNMT1) in ERα-positive BC cells. Subsequent enrichment analysis illustrated that ESR1 methylation is strongly correlated with cell adhesion and junction. Knocking down DNMT3B could partially reverse SNAI2 overexpression-induced cell proliferation, migration, and invasion. Moreover, high DNMT3B expression predicted poor relapse-free survival and overall survival in ERα-positive BC patients. In conclusion, this study demonstrated the novel mechanisms of the ESR1 methylation mediated with the SNAI2/DNMT3B complex and enhanced awareness of ESR1 methylation's role in promoting epithelial-mesenchymal transition in BC.

Coexistence of Superhardness and Metal-Like Electrical Conductivity in High-Entropy Dodecaboride Composite with Atomic-Scale Interlocks.

High electrical conductivity and super high hardness are two sought-after material properties, but both are contradictory because the effective suppression of dislocation movement generally increases the scattering of conducting electrons. Here we synthesized a high-entropy dodecaboride composite (HEDC) with a large number of atomic-scale interlocking layers. It shows a Vickers hardness of 51.2 ± 3.6 GPa under an applied load of 0.49 N and an electrical resistivity of 44.5 µΩ·cm at room temperature. Such HEDC achieves superhardness by inheriting the high intrinsic hardness of its constituent phases and restricting the dislocation motion to further enhance the extrinsic hardness through forming numerous atom-scale interlocks between different slip systems. Moreover, the HEDC maintains the excellent electrical conductivity of the constituent borides, and the competition between two correlating structures produces the special kind of coherent boundary that minimizes the scattering of conducting electrons and does not largely deteriorate the electrical conductivity.

Novel Dual-Mode NIR-II/MRI Nanoprobe Targeting PD-L1 Accurately Evaluates the Efficacy of Immunotherapy for Triple-Negative Breast Cancer.

Background: Durable responses to immune-checkpoint blocking therapy (ICT) targeting programmed cell death protein-1/ligand-1 (PD-1/PD-L1) have improved outcomes for patients with triple negative breast cancer (TNBC). Unfortunately, only 19-23% of patients benefit from ICT. Hence, non-invasive strategies evaluating responses to therapy and selecting patients who will benefit from ICT are critical issues for TNBC immunotherapy. Methods: We developed a novel nanoparticle-Atezolizumab (NPs-Ate) consisting of indocyanine green (ICG), gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA), human serum albumin (HSA), and Atezolizumab. The efficiency of Gd-DTPA linking was verified using mass spectrometry, and the size of NPs-Ate was characterized using Nano-flow cytometry. The synthesized NPs-Ate were evaluated for fluorescence stability, penetration depth, and target specificity. TNBC cell lines and tumor-bearing mice models were used to identify the feasibility of this dual-modal second near-infrared/magnetic resonance imaging (NIR-II/MRI) system. Additionally, ICT combination with chemotherapy or radiotherapy in TNBC tumor-bearing mice models were used to assess dynamic changes of PD-L1 and predicted therapeutic responses with NPs-Ate. Results: Atezolizumab, a monoclonal antibody, was successfully labeled with ICG and Gd-DTPA to generate NPs-Ate. This demonstrated strong fluorescence signals in our NIR-II imaging system, and relaxivity (γ1) of 9.77 mM-1 s-1. In tumor-bearing mice, the NIR-II imaging signal background ratio (SBR) reached its peak of 11.51 at 36 hours, while the MRI imaging SBR reached its highest as 1.95 after 12 hours of tracer injection. NPs-Ate specifically targets cells and tumors expressing PD-L1, enabling monitoring of PD-L1 status during immunotherapy. Combining therapies led to inhibited tumor growth, prolonged survival, and increased PD-L1 expression, effectively monitored using the non-invasive NPs-Ate imaging system. Conclusion: The NIR-II/MRI NPs-Ate effectively reflected PD-L1 status during immunotherapy. Real-time and non-invasive immunotherapy and response/prognosis monitoring under NIR-II/MRI imaging guidance in TNBC is a promising and innovative technology with potential for extensive clinical applications in the future.

Protocol for constructing GQD-PMO functionalized FET-biosensor for ultrasensitive exosomal miRNA detection.

Here, we present a protocol for constructing an ultrasensitive biosensor for exosomal-miRNA detection. We describe steps for preparing graphene quantum dot-phosphorodiamidate morpholino oligomer hybrids, depositing them onto the reduced graphene oxide field surface, hybridizing analyte miRNA with the sensor probe, and capturing and calculating electrical signals. We also detail procedures for optimizing biosensor construction and evaluating performance. By quantifying plasma exosomal miRNA21, this protocol can identify cancer patients from healthy individuals. For complete details on the use and execution of this protocol, please refer to Li et al.1.

Effect of Toll-like receptor 4 deficiency on clinical severity and expression of Th1/Th2/Th17-associated cytokines in a murine model of experimental autoimmune neuritis.

Introduction: The aim was to observe the effect of Toll-like receptor 4 (TLR4) deficiency on clinical severity and expression of Th1/Th2/Th17-associated cytokines in experimental autoimmune neuritis (EAN). Material and methods: We selected C57BL/10 wild type (WT) mice and TLR4 knockout (KO) mice with the C57BL/10 background for induction of the EAN model by immunizing mice twice (days 0 and 8) via subcutaneous injection of 180 µg P0 peptide 180-199 emulsion in 25 µl of PBS and 0.5 mg Mycobacterium tuberculosis (Difco, USA) in 25 µl of Freund's incomplete adjuvant into the back of mice. The concentrations of serum cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ and TNF) were determined using the Ms Th1/Th2/Th17 CBA kit. Results: We found that TLR4 deficiency could attenuate the clinical severity and delay the onset of EAN. Moreover, our data showed that the sera levels of IFN-γ, TNF, IL-6 and IL-17A were elevated in the WT mice with EAN when compared with the naive WT mice, but only the production of IL-17A was significantly lower in the TLR4 KO mice with EAN than in their WT counterparts. Conclusions: Based on these findings, TLR4 may contribute to the pathogenesis of EAN by regulating Th17 cells and the production of Th17-associated factors. However, the exact mechanism remains unclear and more evidence is needed to elucidate its role in EAN.

Development of a Rare Earth Nanoprobe Enables In Vivo Real-Time Detection of Sentinel Lymph Node Metastasis of Breast Cancer Using NIR-IIb Imaging.

Sentinel lymph node (SLN) biopsy plays a critical role in axillary staging of breast cancer. However, traditional SLN mapping does not accurately discern the presence or absence of metastatic disease. Detection of SLN metastasis largely hinges on examination of frozen sections or paraffin-embedded tissues post-SLN biopsy. To improve detection of SLN metastasis, we developed a second near-infrared (NIR-II) in vivo fluorescence imaging system, pairing erbium-based rare-earth nanoparticles (ErNP) with bright down-conversion fluorescence at 1,556 nm. To visualize SLNs bearing breast cancer, ErNPs were modified by balixafortide (ErNPs@POL6326), a peptide antagonist of the chemokine receptor CXCR4. The ErNPs@POL6326 probes readily drained into SLNs when delivered subcutaneously, entering metastatic breast tumor cells specifically via CXCR4-mediated endocytosis. NIR fluorescence signals increased significantly in tumor-positive versus tumor-negative SLNs, enabling accurate determination of SLN breast cancer metastasis. In a syngeneic mouse mammary tumor model and a human breast cancer xenograft model, sensitivity for SLN metastasis detection was 92.86% and 93.33%, respectively, and specificity was 96.15% and 96.08%, respectively. Of note, the probes accurately detected both macrometastases and micrometastases in SLNs. These results overall underscore the potential of ErNPs@POL6326 for real-time visualization of SLNs and in vivo screening for SLN metastasis. SIGNIFICANCE: NIR-IIb imaging of a rare-earth nanoprobe that is specifically taken up by breast cancer cells can accurately detect breast cancer macrometastases and micrometastases in sentinel lymph nodes.

Functionalized carbon nanotube field-effect transistor biosensor for highly sensitive detection of exosomal protein.

Since the exosomal protein level is related to many diseases, sensitive detection of exosomal protein is highly desirable. Here, we describe a polymer-sorted high-purity semiconducting carbon nanotubes (CNTs) films-based field-effect transistor (FET) biosensor for ultrasensitive and label-free detection of MUC1, a transmembrane protein highly expressed in breast cancer exosomes. Polymer-sorted semiconducting CNTs hold advantages including high purity (>99%), high CNT concentration, and short processing time (<1 h), but they are difficult to be stably functionalized with biomolecules because of lacking hanging bonds on their surface. To solve this issue, poly-lysine (PLL) was employed to modify the CNT films after they were deposited on the sensing channel surface of the fabricated FET chip. To specifically recognize the exosomal protein, sulfhydryl aptamer probes were immobilized on the gold nanoparticles (AuNPs) surface that was assembled on PLL substrate. The aptamer-modified CNT FET was capable of sensitively and selectively detecting exosomal MUC1 as high as 0.34 fg/mL. Moreover, the CNT FET biosensor was able to recognize breast cancer patients from healthy individuals by comparing the expression level of exosomal MUC1. The developed CNT FET biosensor is expected to be a novel assay for early diagnosis of cancer.

Notch1 promotes resistance to cisplatin by up-regulating Ecto-5'-nucleotidase (CD73) in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is an aggressive molecular subtype that due to lack of druggable targets is treated with chemotherapy as standard of care. However, TNBC is prone to chemoresistance and associates with poor survival. The aim of this study was to explore the molecular mechanisms of chemoresistance in TNBC. Firstly, we found that the mRNA expression of Notch1 and CD73 in cisplatin-treated patient material associated with poor clinical outcome. Further, both were upregulated at the protein level in cisplatin-resistant TNBC cell lines. Overexpression of Notch1 intracellular domain (termed N1ICD) increased expression of CD73, whereas knockdown of Notch1 decreased CD73 expression. Using chromatin immunoprecipitation and Dual-Luciferase assay it was identified that N1ICD directly bound the CD73 promoter and activated transcription. Taken together, these findings suggest CD73 as a direct downstream target of Notch1, providing an additional layer to the mechanisms underlying Notch1-mediated cisplatin resistance in TNBC.

Dual-Needle Field-Effect Transistor Biosensor for In Vivo pH Monitoring.

Local pH of the brain microenvironment is a prominent indicator for assessing health status and is closely related to many diseases; therefore, the development of effective in vivo pH methods is of great importance. This work demonstrates a dual-needle biosensor based on a solution-gate field-effect transistor (FET) for selective and sensitive monitoring of pH in cerebrospinal fluid in the central nervous system. The sensor consists of two parts: a needle FET modified with high-purity carbon nanotubes for electrical signal conduction and a needle gate modified with polyaniline for specific pH response. Based on the device's specific shape and sensing characteristics, the dual-needle sensor is sensitive to the measurement of pH in the living brain while maintaining excellent stability. The prepared dual-needle biosensor exhibits a high Nernstian response of 53.7 mV/pH over a wide pH range from 4.0 to 9.0 and excellent selectivity toward pH against other potential interfering species in the brain. Either in the case of directly injecting weak acids and bases into the rat brain or in the constructed acute acid-base poisoning model, the dual-needle biosensor can respond sensitively to the pH changes of the rat brain. This work has produced a unique dual-needle FET biosensor with high reliability and stability, which provides a new method for real-time monitoring of dynamic pH changes in the body.