Peptide-Assembled Graphene Oxide as a Fluorescent Turn-On Sensor for Lipopolysaccharide (Endotoxin) Detection

Lipopolysaccharide (LPS) is a toxic inflammatory stimulator released from the outer cell membrane of Gram-negative bacteria, known to be directly related to, for example, septic shock, that causes millions of casualties annually. This number could potentially be lowered significantly if specific, sensitive, and more simply applicable LPS biosensors existed. In this work, we present a facile, sensitive and selective LPS sensor, developed by assembling tetramethylrhodamine-labeled LPS-binding peptides on graphene oxide (GO). The fluorescence of the dye-labeled peptide is quenched upon interaction with GO. Specific binding to LPS triggers the release of the peptide-LPS complex from GO, resulting in fluorescence recovery. This fluorescent turn-on sensor offers an estimated limit of detection of 130 pM, which is the lowest ever reported among all synthetic LPS sensors to date. Importantly, this sensor is applicable for detection of LPS in commonly used clinical injectable fluids, and it enables selective detection of LPS from different bacterial strains as well as LPS on the membrane of living E. coli

Hematology in DENV-infected mice treated once with 7.5% NaCl at day 6 post-infection.

<p>Groups of 8–9 week-old AG129 mice were left uninfected or were sc infected with D2Y98P-PP1 virus and at day 6 pi., they were treated with a single bolus (iv; 4 mL/kg body weight) of 7.5% NaCl (HTS) or PBS as indicated. At the indicated time points post-infection, 5 mice per group were euthanized and bled for hematology analysis. Results are expressed as the mean ± SD of the 5 individual measurements. Legend: WBC, white blood cells; NEU, neutrophils; LYM, lymphocytes; PLT, platelets; RBC, red blood cells; HCT, hematocrit; ALB, albumin.</p

Survival rate, clinical score and vascular leakage in DENV-infected mice treated once with 7.5% or 5% NaCl at day 6 post-infection.

<p>Groups of 8–9 week-old AG129 mice were sc. infected with D2Y98P-PP1 strain or left uninfected as indicated. At day 6 p.i., they were iv. administered with a single bolus (4 ml/kg body weight) of sterile 5% or 7.5% NaCl. (A) Survival rate (n = 10). (B) Clinical scores (n = 10) see legend in Fig. 1. (C) Vascular leakage. At the indicated time points post-treatment, the animals were assessed for vascular leakage and the level of Evan’s blue extravasation was quantified in various organs (as indicated) from 5 individual mice per time point. Results are expressed as fold change compared to uninfected untreated control mice. *p<0.05.</p

Survival rate, clinical score and vascular leakage in DENV-infected mice treated once or three times with 7.5% NaCl.

<p>Groups of 8–9 week-old AG129 mice were sc. infected with D2Y98P-PP1 strain. At day 6 p.i., they were iv. administered with a volume (4 ml/kg body weight) of sterile 7.5% NaCl (HTS) or 0.9% NaCl (PBS) once (D6), or once for three consecutive days (D6–D8) as indicated. (A) Survival rate (n = 10). (B) Clinical scores (n = 10): 0: Healthy; 1: Ruffled fur; 2: Hunched back; 3: Severe Diarrhea; 4: Moribund stage; 5: Severe weight loss. (C) Systemic vascular leakage in infected mice. Three hours post-HTS or PBS treatment, DENV-infected mice (n = 5) were assessed for vascular leakage and the quantity of Evan’s blue dye was determined in various organs from the individual mice as indicated. Results are expressed as fold change compared to uninfected untreated control mice. (D) Systemic vascular leakage in uninfected mice. Uninfected mice (n = 5) were subjected to HTS treatment (once or once daily for three days) followed by Evan’s blue assay 3 hrs after the last administration.</p

Effect of neutrophil depletion in DENV-infected mice.

<p>Groups of 8–9 week-old AG129 mice were left uninfected or were sc infected with D2Y98P-PP1 virus. At day 5 and 6 p.i., groups were ip. injected with NIMP-R14 antibodies. A control group was iv. injected with a bolus of 7.5% NaCl (4 ml/kg) at day 6 p.i. (A) Survival rate (n = 10). (B) Clinical score (n = 10) See legend of Fig. 1. (C) Vascular leakage. At day 7 p.i., mice (n = 5) were euthanized and Evan’s blue extravasation assay was performed. Results are expressed as fold change compared to uninfected untreated control mice. *, p<0.05. (D) Serum levels of soluble factors. At day 7 p.i., mice (n = 5) were euthanized and the serum levels of IL-6, TNF-α, C5a, MMP9, VEGFA and VEGFR2 were measured. The results are expressed as the average of 5 individual samples ± SD. *p<0.05.</p

Histology examination and liver enzymes from DENV-infected mice treated once with 7.5% NaCl at day 6 post-infection.

<p>Groups of 8–9 week-old AG129 mice were left uninfected or were sc infected with D2Y98P-PP1 virus and at day 6 pi., they were treated with a single bolus (iv; 4 mL/kg body weight) of 7.5% NaCl (HTS) or PBS as indicated. At the indicated time points post-infection, the animals were euthanized and their liver (A), intestines (B) and brain (C) were harvested, fixed and processed for H&E staining. Observations were made at x200 (A, B) and x400 (C) magnification. Representative sections from 3 individual mice are shown. (D) Levels of serum alanine (ALT) and aspartate (AST) transaminases were monitored over time post-infection upon treatment with HTS or PBS as indicated. Results are expressed as the mean ± SD of five individual mice per group per time point.</p

Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort

Individuals with rare kidney diseases account for 5-10% of people with chronic kidney disease, but constitute more than 25% of patients receiving kidney replacement therapy. The National Registry of Rare Kidney Diseases (RaDaR) gathers longitudinal data from patients with these conditions, which we used to study disease progression and outcomes of death and kidney failure.People aged 0-96 years living with 28 types of rare kidney diseases were recruited from 108 UK renal care facilities. The primary outcomes were cumulative incidence of mortality and kidney failure in individuals with rare kidney diseases, which were calculated and compared with that of unselected patients with chronic kidney disease. Cumulative incidence and Kaplan-Meier survival estimates were calculated for the following outcomes: median age at kidney failure; median age at death; time from start of dialysis to death; and time from diagnosis to estimated glomerular filtration rate (eGFR) thresholds, allowing calculation of time from last eGFR of 75 mL/min per 1·73 m2 or more to first eGFR of less than 30 mL/min per 1·73 m2 (the therapeutic trial window).Between Jan 18, 2010, and July 25, 2022, 27 285 participants were recruited to RaDaR. Median follow-up time from diagnosis was 9·6 years (IQR 5·9-16·7). RaDaR participants had significantly higher 5-year cumulative incidence of kidney failure than 2·81 million UK patients with all-cause chronic kidney disease (28% vs 1%; p Background Methods Findings Interpretation Funding</p