Graphene Oxide-Mediated Regulation of Volume Exclusion and Wettability in Biomimetic Phosphorylation-Responsive Ionic Gates.

Replicating phosphorylation-responsive ionic gates via artificial fluidic systems is essential for biomolecular detection and cellular communication research. However, current approaches to governing the gates primarily rely on volume exclusion or surface charge modulation. To overcome this limitation and enhance ion transport controllability, we introduce graphene oxide (GO) into nanochannel systems, simultaneously regulating the volume exclusion and wettability. Moreover, inspired by (cAMP)-dependent protein kinase A (PKA)-regulated L-type Ca2+ channels, we employ peptides for phosphorylation which preserves them as nanoadhesives to coat nanochannels with GO. The coating boosts steric hindrance and diminishes wettability, creating a substantial ion conduction barrier, which represents a significant advancement in achieving precise ion transport regulation in abiotic nanochannels. Leveraging the mechanism, we also fabricated a sensitive biosensor for PKA activity detection and inhibition exploration. The combined regulation of volume exclusion and wettability offers an appealing strategy for controlled nanofluidic manipulation with promising biomedical applications in diagnosis and drug discovery.

Engineered Escherichia coli as a Controlled-Release Biocarrier for Electrochemical Immunoassay.

Micro/nanocarriers hold great potential in bioanalysis for molecular recognition and signal amplification but are frequently hampered by harsh synthesis conditions and time-consuming labeling processes. Herein, we demonstrate that Escherichia coli (Ec) can be engineered as an efficient biocarrier for electrochemical immunoassay, which can load ultrahigh amounts of redox indicators and simultaneously be decorated with detection antibodies via a facile polydopamine (PDA)-mediated coating approach. Compared with conventional carrier materials, the entire preparation of the Ec biocarrier is simple, highly sustainable, and reproducible. Moreover, immune recognition and electrochemical transduction are performed independently, which eliminates the accumulation of biological interference on the electrode and simplifies electrode fabrication. Using human epidermal growth factor receptor 2 (HER2) as the model target, the proposed immunosensor exhibits excellent analytical performance with a low detection limit of 35 pg/mL. The successful design and deployment of Ec biocarrier may provide new guidance for developing biohybrids in biosensing applications.

Molecular Characterization of Exosomes for Subtype-Based Diagnosis of Breast Cancer.

Breast cancer is very heterogeneous and the most frequently diagnosed cancer worldwide, and precise therapy targeting specific subtypes may improve the survival rates of breast cancer patients. In this study, we designed a biomimetic vesicle by camouflaging catalytic DNA machinery with a breast cancer cell membrane, which enabled the molecular classification of circulating exosomes for subtype-based diagnosis through homotypic recognition. In addition, the vesicles specifically targeted and fused with breast cancer exosomes with phenotypic homology and manipulated the DNA machinery to amplify electrochemical signaling using exosomal RNA as an endogenous trigger. The biomimetic vesicles prepared with MCF-7 cancer cell-derived membranes were shown to recognize estrogen receptor-positive breast cancer exosomes and exhibited a low detection limit of 557 particles mL-1 with microRNA-375 used as the endogenous biomarker. Furthermore, the biomimetic vesicles prepared with MDA-MB-231 cancer cell-derived membranes displayed satisfactory performance in a homotypic analysis of triple-negative breast cancer exosomes with a potential therapeutic target, PD-L1 mRNA, used as the endogenous biomarker. Most importantly, cross-validation experiments confirmed the high accuracy and selectivity of this homotypic recognition-driven analysis for molecular subtyping of breast cancer. When applied to clinical samples of breast cancer patients, the vesicles demonstrated feasibility and reliability for evaluating the molecular features of cancer cell-derived exosomes and enabled stage-specific monitoring of breast cancer patients because the electrochemical signals showed a positive correlation with disease progression. Therefore, this work may provide new ideas for the precise diagnosis and personalized treatment of breast cancer patients throughout the whole disease process.

Liver fat as a dietary target by Chinese Medical Nutrition Therapy (CMNT) diet for treating type 2 diabetes with non-alcoholic fatty liver disease: study protocol for a randomised controlled trial.

INTRODUCTION: Type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) often coexist and increase risk for developing liver fibrosis and diabetes complications if no effective measures are taken. Dietary intervention is known to be able to achieve diabetes remission, while evidence regarding the long-term effect on liver fat is limited for comorbidity management of type 2 diabetes and NAFLD. This study aims to investigate the long-term effect of a Chinese Medical Nutrition Therapy (CMNT) diet accompanied by intermittent energy restriction on reducing liver fat and glycated haemoglobin (HbA1c) in patients with type 2 diabetes and NAFLD. METHODS AND ANALYSIS: This is a multicentre two-armed parallel randomised controlled trial study. 120 participants with type 2 diabetes and NAFLD will be recruited from the physical examination centres of multiple hospitals in China. Participants will be randomly allocated 1:1 to either the CMNT group or the usual care group. The CMNT group will be instructed to consume the provided specific meal replacement Chinese medicinal foods consisting of 6 cycles of 5 consecutive days followed by 10 days of regular food intake. The usual care group will be given standard dietary advice. Primary outcomes are changes in the controlled attenuation parameter value by transient elastography and HbA1c level. Secondary outcomes include differences in anthropometrics, clinical blood markers, questionnaires, gut microbiota and metabolomics. Further follow-up will be performed at 6 months, 1 year and 2 years. ETHICS AND DISSEMINATION: The study protocol was approved by the Biomedical Research Ethics Committee of Hunan Agricultural University (BRECHAU20200235).The results will be disseminated via relevant peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT05439226.

Overexpressions of RACK1 and CD147 associated with poor prognosis in stage T1 pulmonary adenocarcinoma.

BACKGROUND: RACK1 has been shown to be able to interact with some key cellular proteins involved in tumor development and progression. Our study showed that the expressions of RACK1 and CD147 are correlated with each other. The purpose of this study is to clarify the relationship between expression of RACK1 and CD147 in 180 patients with operable stage T1 human pulmonary adenocarcinoma and their clinicopathological features and prognostic significance. METHODS: DNA transfection and RNA interference of RACK1 were conducted to produce pulmonary adenocarcinoma cell lines with differential RACK1 expression. Western blot and RT-PCR were used to quantify RACK1 and CD147 expression in protein and mRNA levels in pulmonary adenocarcinoma cell lines. Immunohistochemistry, double-labeling immunofluorescence, confocal laser scanning microscopy, and Western blot were used to correlate the clinicopathological significance of RACK1 and CD147 expression in cases of stage T1 pulmonary adenocarcinoma. RESULTS: We detected high levels of RACK1 and CD147 mRNA as well as protein expression in pulmonary adenocarcinoma in vitro. In pulmonary adenocarcinoma, the expression of RACK1 and CD147 were correlated both in vitro and in vivo. Our clinicopathological analysis demonstrated that RACK1 or CD147 expression correlated with higher incidence of lymph node metastasis and lower differentiation than tumors that were negative for expression of either RACK1 or CD147. The expression of RACK1 and CD147 was not associated with the patient age or gender. Multivariate analysis demonstrated that the co-overexpression of RACK1 and CD147 was an independent prognostic factor for stage T1 pulmonary adenocarcinoma (P = 0.012). CONCLUSIONS: Tumor invasiveness is associated with expression of RACK1 and CD147 in pulmonary adenocarcinoma. The co-expression of RACK1 and CD147 could be an important prognostic biomarker for stage T1 pulmonary adenocarcinoma.

A peptides-based biosensor with target-triggered charge-switchable property for simple and sensitive detection of Granzyme B.

Granzyme B (GrB) is a serine protease released by natural killer cells and cytotoxic T lymphocytes during immune responses, which not only plays a role in tumor diagnosis but also provides valuable guidance during tumor treatment. In this work, we have designed a charge-switching peptide to fabricate an electrochemical biosensor for quantitative analysis of GrB. Specifically, the designed zwitterionic peptide is in an electrically neutral state before activation, and a door lock structure (proline) is constructed by utilizing the selectivity of carboxypeptidase A (CPA) to the carboxy-terminus of the peptide chain. The door lock is opened when the target is present, allowing CPA to hydrolyze the peptide. At this time, the peptide will convert from neutral to positive, triggering the assembly of a positively charged peptide layer on the electrode surface, resulting in a signal change. Studies have shown that the biosensor has good analytical performance, with a detection range of 0.01 pM-8 pM and a detection limit as low as 3.5 fM. Moreover, the developed biosensor has been effectively applied to the analysis of clinical samples, demonstrating its ability to monitor tumor progression and treatment with clinical applications.

An electrochemical biosensor based on electroactive peptide nanoprobes for the sensitive analysis of tumor cells.

Peptides possess many appealing and desirable features, which have attracted increasing attention in the field of electrochemical biosensing. However, peptides hardly produce noticeable electronic signals in response to target binding events. In this work, amphipathic peptides FFFGGGGRGDS with both target recognition and self-assembly capabilities are designed to be co-assembled with the electroactive species ferrocenecarboxylic acid (FcCOOH). Furthermore, the resultant electroactive peptide nanoprobes (ePNPs) are applied for sensitive electrochemical analysis of tumor cells. Specifically, tumor cells are captured by the electrode modified with the corresponding DNA aptamers, and ePNPs can then selectively bind to integrin proteins on the cell surface, thereby accompanied by a remarkable increase of electrochemical signal. Taking the assay of MDA-MB-231 cells, the fabricated biosensor can detect cancer cells with a detection limit of 7 cells mL-1. Moreover, the ePNPs can act as a universal probe for the detection of different cell lines. Given the merits of easy synthesis, convenient operation, and favorable analytical performance, the proposed biosensor exhibits great potential in developing peptide-based electrochemical biosensing for clinical applications.

Histostar-Functionalized Covalent Organic Framework for Electrochemical Detection of Exosomes.

Covalent organic frameworks (COFs) are gaining growing interest owing to their various structures and versatility. Since their specific physical-chemical characteristics endow them great usage potentiality in biosensing, we herein have synthesized spherical COFs with regular shape and good dispersion, which are further used for the design of a novel nanoprobe by modifying Histostar on the surface of the COFs. Moreover, we have applied a nanoprobe for the fabrication of an electrochemical biosensor to detect exosomes. Since Histostar is a special polymer, conjugated with many secondary antibodies (IgG), and HRP can increase the availability of HRP at the antigenic site, the biosensor can have a strong signal amplification ability. Meanwhile, since COFs with high porosity can be loaded with a huge amount of Histostar, the sensitivity of the biosensor can be further improved. With such a design, the proposed biosensor can achieve a low exosomes detection limit of 318 particles/µL, and a wide linear detection range from 103 particles/µL to 108 particles/µL. So, this work may offer a promising platform for the ultrasensitive detection of exosomes.

Improvement of magnesium isoglycyrrhizinate on DSS-induced acute and chronic colitis.

Inflammatory bowel disease (IBD) is a worldwide prototypical complex disease, owing to its multifactorial causes, relapsing and remitting condition and high incidence. Thus, effective therapeutic approaches need to be developed for patients with IBD. Currently, we reported the improving effect of magnesium isoglycyrrhizinate on colitis induced by dextran sulfate sodium (DSS). We found that magnesium isoglycyrrhizinate treatment significantly alleviated DSS-induced acute and chronic colitis by inhibiting the inflammatory response characterized by reduce of the infiltrations of immune cell and the level of pro-inflammatory cytokines. Besides, magnesium isoglycyrrhizinate treatment significantly inhibited the level of ROS and decreased the gut barrier destruction after DSS treatment. Furthermore, the results also showed that administration of magnesium isoglycyrrhizinate significantly reduced the colonic fibrosis. Taken together, these results revealed the potency of magnesium isoglycyrrhizinate on the intestinal inflammation, by which points to the possible use of magnesium isoglycyrrhizinate for IBD therapy in clinical applications.

Curcumin Prevents Brain Damage and Cognitive Dysfunction During Ischemic-reperfusion Through the Regulation of miR-7-5p.

OBJECTIVE: This study was to investigate the potential protective effects of curcumin in cerebral ischemia-reperfusion (CIR) and its regulation of miR-7. METHODS: Rats were occluded by middle cerebral artery occlusion (MCAO) for 1.5 h and reperfused for 2 h to establish a local CIR model. After 24 hours of model establishment, MCAO rats were given curcumin for 3 days by intragastric administration. PC12 cells were cultured for 6 h in oxygen-glucose deprivation medium and then reoxygenated for 24 h to establish an oxygenglucose deprivation/reoxygenation (OGD/R) model. The OGD/R model cells were treated with curcumin for 48 h. RESULTS: Curcumin inhibited the decrease of miR-7-5p expression and an increase of RelA p65 expression induced by CIR and ODG/R. RelA p65 was a target of miR-7-5p. MiR-7-5p antagonists were able to counteract the effect of curcumin on the expression of RelA p65 in ischemic brain tissue of MCAO rats and OGD/R model cells. Curcumin improved OGD/R-induced inhibition of cell activity, necrosis and apoptosis. Curcumin significantly reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1ß, reactive oxygen species (ROS) and malondialdehyde (MDA) and increased the activity of superoxide dismutases (SOD) and catalase (CAT) in OGD/R-induced cells. Curcumin may inhibit OGD/R-induced cell damage by regulating miR-7-5p. Curcumin improved cerebral infarction, nerve damage and cognitive dysfunction in rats with CIR, which may be related to the regulation of miR-7-5p/RelA p65 axis. CONCLUSION: Curcumin exerts cerebral protection by attenuating cell necrosis and apoptosis, inflammatory response and oxidative stress following CIR, which may be related to its regulation of the miR-7/RELA p65 axis.