Detection Of B-type Natriuretic Peptide Research Articles

Flexible Scaffold Modulation of Spatial Structure and Function of Hierarchically Porous Nanoparticle@ZIF-8 Composites to Enhance Field Deployable Disease Diagnostics.

Catalytic nanoparticle@metal-organic framework (MOF) composites have attracted significant interest in point-of-care testing (POCT) owing to their prominent catalytic activity. However, the trade-off between high loading efficiency and high catalytic activity remains challenging because high concentrations of nanoparticles tend to cause the misjoining and collapse of the MOFs. Herein, a facile strategy is reported to encapsulate high concentrations of platinum (Pt) nanoparticles into zeolitic imidazolate framework-8 (ZIF-8) using polydopamine (PDA) as a support for Pt@ZIF-8 and as a flexible scaffold for further immobilization of Pt nanoparticles. The resulting composite (Pt@ZIF-8@PDA@Pt) exhibits ultrahigh Pt nanoparticle loading efficiency, exceptional catalytic activity, stability, and a bright colorimetric signal. Following integration with lateral flow immunoassay (LFIA), the detection limits for pre- and post-catalysis detection of B-type natriuretic peptide (NT-proBNP) are 0.18 and 0.015ng mL-1, respectively, representing a 6-fold and 70-fold improvement compared to gold nanoparticle-based LFIA. Moreover, Pt@ZIF-8@PDA@Pt-based LFIA achieves 100% diagnostic sensitivity for NT-proBNP in a cohort of 184 clinical samples.

A novel electrochemical biosensor for B-type natriuretic peptide detection based on CRISPR/Cas13a and chain substitution reaction

B-type natriuretic peptide (BNP) is a biomarker for heart failure, a serious and prevalent disease that requires rapid and accurate diagnosis. In this study, we developed a novel electrochemical biosensor for BNP detection based on CRISPR/Cas13a and chain substitution reaction. The biosensor consists of a DNA aptamer that specifically binds to BNP, a T7 RNA polymerase that amplifies the signal, a CRISPR/Cas13a system that cleaves the target RNA, and a two-dimensional DNA nanoprobe that generates an electrochemical signal. The biosensor exhibits high sensitivity, specificity, and stability, with a detection limit of 0.74 aM. The biosensor can also detect BNP in human serum samples with negligible interference, demonstrating its potential for clinical and point-of-care applications. This study presents a novel strategy for integrating CRISPR/Cas13a and chain substitution reaction into biosensor design, offering a versatile and effective platform for biomolecule detection.

Entropy-driven reactions for controlling CRISPR/Cas12a and constructing an electrochemical biosensor for cardiac biomarkers detection.

An electrochemical biosensor is reported for controlling CRISPR/Cas12a activity through the utilization of entropy-driven reactions, alongside the construction of a highly sensitive biosensor for B-type natriuretic peptide (BNP) detection. In the biosensor, entropy-driven reactions are employed to regulate the activity of CRISPR/Cas12a-a gene editing tool-capable of nonspecific cleavage of single-stranded DNA (ssDNA). The biosensor architecture encompasses an electrode that is modified with ssDNA probes designed to hybridize with target BNP aptamers. These aptamers, furnished with labeled ssDNA triggers, facilitate the activation of CRISPR/Cas12a through interaction with its guide RNA. Upon the presence of BNP, it associates with the aptamers, subsequently liberating the triggers that instigate the entropy-driven reactions. As a consequence of these reactions, more stable duplexes emerge between the triggers and guide RNA, thereby activating CRISPR/Cas12a. The activated CRISPR/Cas12a subsequently executes cleavage of ssDNA probes residing on the electrode surface, culminating in the generation of an electrochemical signal directly (the calibration plots of differential pulse voltammetric detectionwere acquired at a working potential of 0.2V (vs. ref. electrode)) proportional to the BNP concentration. Validation of the biosensor's performance is undertaken, wherein BNP detection is demonstrated in both buffer and human serum samples. Evident in the findings is the biosensor's discernible sensitivity and specificity for BNP detection, exemplified by a detection limit of 13.53 fM and a lack of interference originating from other cardiac biomarkers, respectively. Furthermore, the biosensor's potential to discriminate between healthy individuals and those afflicted by heart failure, predicated on distinctive BNP levels, is illustrated.

Solid-Phase Screening and Synthesis of Molecularly Imprinted Nanoparticles for Selective Recognition and Detection of Brain Natriuretic Peptide.

A new recognition method is explored for the rapid detection of B-type natriuretic peptide (BNP) based on the rational design and solid-phase synthesis of molecularly imprinted nanoparticles (nanoMIP) encapsulated with carbon dots. The nanosized magnetic template is first prepared by attaching the epitope of BNP on amino-functionalized magnetic carriers. High-dilution polymerization of monomers in the presence of magnetic template generates lightly crosslinked imprinted nanoparticles. To obtain the optimal MIP formulation, a new combinatorial screening approach is developed by a competitive fluorescence assay using the magnetic template. The resultant nanoMIP exhibits high affinity and selectivity toward BNP with an equilibrium dissociation constant (KD ) of ≈10-11 m. The proposed assay allows fast BNP detection within ≈7min with a linear range of its concentration from 0.25 to 5000 pg mL-1 and a limit of detection of 0.208 pg mL-1 (S/N = 3). To demonstrate its practicability in clinical diagnosis, unknown real serum samples from 160 individuals are analyzed and the relative standard deviation is less than 4.43%. Compared with the routine electrochemiluminescence detection method that is widely used in hospital, the relative error is less than 4.98% and the correlation coefficient is 0.994.

An Immunocolorimetric Sensing System for Highly Sensitive and High-Throughput Detection of BNP with Carbon-Gold Nanocomposites Amplification.

Conventional immunocolorimetric sensing of biomolecules continues to be challenged with low sensitivity although its wide application as a diagnostic tool in medicine and biotechnology. Herein, we present a multifunctional immunocolorimetric sensing system for sensitive and high-throughput detection of B-type natriuretic peptide (BNP) with carbon-gold nanocomposite (CGNs) amplification. Using a “green” strategy, monodisperse carbon nanospheres (CNs) were successfully synthesized by glucose carbonization. A simple and efficient hydrothermal method was developed to assemble abundant gold nanoparticles (AuNPs) onto the surfaces of CNs. The resulting CGNs were characterized and utilized for biomarker detection with superior properties of easy manufacturing, good biocompatibility, satisfactory chemical stability, and high loading capacity for biomolecules. As a proof of concept, the as-prepared CGNs were conjugated with horseradish peroxidase-labeled antibody against BNP (CGNs@AntiBNP-HRP) functioning as the carrier, signal amplifier, and detector for the sensitive detection of BNP. Under optimal conditions, the established CGNs@AntiBNP-HRP immunoprobe remarkably enhanced the detection performance of BNP, achieving signal amplification of more than 9 times compared to the conventional method. Based on our self-developed bionic electronic eye (e-Eye) and CGNs@AntiBNP-HRP immunoprobe, the multifunctional sensing system displayed a wide dynamic linear range of 3.9–500 ng/mL and a LOD of 0.640 ng/mL for BNP detection with high specificity, good accuracy and reproducibility. This portable sensing system with enhanced performance demonstrates great potential for BNP detection in point of care applications, and offers a universal and reliable platform for in vitro biomarker detection.

Defect-rich CoOOH nanorings: A biocompatible and cost-efficient material for clinical diagnosis of children heart failure

Nanomaterials have been widely used in the detection of biomarkers, but only a few of them can be really applied in clinical disease diagnosis in hospital. Herein, we fabricate a kind of defect-rich CoOOH nanorings (NRs) and employ them as probes to improve the clinical diagnosis performance for children heart failure (HF). This diagnosis platform is dependent on ultrasensitive and specific detection of the “gold standard biomarker” of HF, B-type natriuretic peptide (BNP), which is realized based on the prevention of fluorescence resonance energy transfer. The detection range for BNP is 30–800 fg/mL with a limit of detection as low as 30 fg/mL. For diagnosis of a large number of clinical cases of children who behave sign or symptom of HF (respiratory distress, edema, or tachycardia), a very close correlation (r = 0.990) is obtained between this method and commercially available chemiluminescence immunoassay (CLIA, Siemens) that commonly adopted by hospital. It is worth noting that the present method has better diagnostic performance for children HF than CLIA including specificity (84.6% vs 61.5%), accuracy (82.2% vs 66.7%) and positive predictive value (40.0% vs 20.0%). Moreover, this method is more cost-effective than CLIA for BNP detection. The defect-rich, biocompatible, and low-cost CoOOH nanomaterial is promising to be applied in early clinical diagnosis of HF in hospital.

A review of biosensors for the detection of B-type natriuretic peptide as an important cardiovascular biomarker.

Heart disease, as the most serious threat to human health globally, is responsible for rising mortality rates, largely due to lifestyle and diet. Unfortunately, the main problem for patients at high risk of heart disease is the validation of prognostic tests. To this end, the detection of cardiovascular biomarkers has been employed to obtain pathological and physiological information in order to improve prognosis and early-stage diagnosis of chronic heart failure. Short-term changes in B-type natriuretic peptide are known as a standard and important biomarker for diagnosis of heart failure. The most important problem for detection is low concentration and short half-life in the blood. The normal concentration of BNP in blood is less than 7 nM (25 pg/mL), which increases significantly to more than 80 pg/mL. Therefore, the development of new biosensors with better sensitivity, detection limit, and dynamic range than current commercial kits is urgently needed. This review classifies the biosensors designed for detection of BNP into electrochemical, optical, microfluidic, and lateral-flow immunoassay techniques. The review clearly demonstrates that a variety of immunoassay, aptasensor, enzymatic and catalytic nanomaterials, and fluorophores have been successfully employed for detection of BNP at low attomolar ranges. Dtection of B-type natriuretic peptide with biosensors.

Bionic E-Eye Based High-Throughput Immunocolorimetric Sensor System for Sensitive Detection BNP in Blood through Carbon-Gold Nanocomposites

Introduction Precise and sensitive detection of protein biomarkers is of vital importance in clinical diagnosis and biomedical research. To date, enzyme-linked immunosorbent assay (ELISA) remains the gold standard in detecting protein biomarkers due to the robust properties of simple operation, acceptable sensitivity, and automated high throughput [1, 2]. Despite desirable results from ELSA, pursuing high sensitivity and accuracy to meet diagnosis demands is still an ongoing endeavor. For that, nanomaterials behaving with favorable physical properties and biocompatibility may serve as a solution, especially the carbon nanosphere (CN) or gold nanoparticles (AuNPs) that feature strong stability, easy manufacture, low cost, and environment-friendly, and abundant active sites [3, 4].Heart failure (HF) is one of the most threatening cardiovascular diseases. B-type natriuretic peptide (BNP), a vital cardiac biomarker, has been acknowledged as one of the principal biomarkers for HF [5]. Individuals at risk of HF demonstrate raised BNP in serum and real-time quantification of HF biomarkers, identifying those at highest risk of HF early, and ensuring they receive appropriate treatment can effectively prevent premature death [6]. Although current ELISA-methods for detecting BNP have been developed, there are urgent needs for providing more efficiently and reliably in vitro diagnostic (IVD) methods or point-of-care (POC) devices in BNP clinical measurement.Most of the previous studies for ELISA-based BNP detection required large instruments with high costs such as microplate readers, spectrophotometers. In this work, we adopted a self-developed portable bionic electronic eye (Bionic E-eye) system using a smartphone (iPhone 4S and iPad 3) integrated with simple accessories including a piece of electroluminescent, a wide-angle lens, and a dark hood instead of the commercial microplate reader to make the entire analysis process more intelligent and convenient. In addition, the CN-AuNPs nanocomposites (CGN) we prepared was used as a signal amplifier to develop a high-throughput immunocolorimetric method that sensitively identified BNP through the color change of antibody-antigen reactions using enzyme-substrate and horseradish peroxidase-antibody (pAb-HRP) linked CGN immunoprobe (CGNs@ pAb-HRP). The combination of Bionic E-eye and high-throughput immunocolorimetric system aimed to establish a general and reliable strategy for POC testing (Figure. 1A). Method Monoclonal antibody against BNP were immobilized on the surface of the 96-well plate as capture antibody. Then the different concentrations of BNP were added to the wells. Finally, the HRP-labeled polyclonal BNP (pAb-HRP) antibody or the pAb-HRP modified CGNs (pAb-HRP-CGNs) were added to bind with BNP. After 3,3',5,5'-Tetramethylbenzidine (TMB) and HCl were added, different shades of yellow color related to BNP concentration appeared. Combining with the Bionic E-eye, BNP concentration could be analyzed by image processing. Results and Conclusions To achieve optimally sensitive signal output and fabricate a well-performance immunoprobe, the synthesized conditions were optimized. Under optimal conditions, we have successfully synthesized stable and homogeneous CGNs validated by TEM (Figure. 1B) and XPS. The performance for BNP detection by a commercial microplate reader (Figure. 1C) and Bionic E-eye were evaluated and compared. The detection range of both was comparable (7.8 ppb~125 ppb) while the Bionic E-eye system had a lower limit of detection (LOD) than a commercial microplate reader (4.3 ppb < 7.2 ppb) (Figure. 1D), indicating that compared with a commercial colorimetric reader the self-developed system achieved higher sensitivity which could be attributed to the superiority of saturation channel in HSV or RGB color model the Bionic e-Eye used. In addition, the signal amplifying effect of the pAb-HRP-CGNs probe was also confirmed in the comparison of LOD and detection range with pAb-HRP. Figure. 1E showed that the LOD in the method using pAb-HRP-CGNs reached 0.92 ppb and the wider detection range of 3.9 ppb~250 ppb was achieved compared with that of 7.8 ppb~125 ppb in the non-CGNs method. Based on the above results, this proposed CGNs based detection of BNP with Bionic e-Eye shows promising application prospect but more experimental optimizations should be performed to further improve its performance.

Unexpectedly Low Natriuretic Peptide Levels in Patients With Heart Failure

ObjectivesThe purpose of this study was to determine the frequency of unexpectedly low natriuretic peptide (NP) levels in a clinical population. BackgroundHigher NP concentrations are typically observed as a compensatory response to elevated cardiac wall stress. Under these conditions, low NP levels may be indicative of a “NP deficiency.” MethodsWe identified 3 clinical scenarios in which high B-type natriuretic peptide (BNP) levels would be expected: 1) hospitalization for heart failure (HF); 2) abnormal cardiac structure or function; or 3) abnormal hemodynamics. In Vanderbilt’s electronic health record, 47,970 adult patients had BNP measurements. A total of 13,613 patients had at least 1 of the 3 conditions (hospitalized HF, n = 9,153; abnormal cardiac structure/function, n = 7,041; abnormal hemodynamics, n = 363). We quantified the frequency of low BNP levels. We performed whole exome sequencing of the NPPB gene in a subset of 9 patients. ResultsVery low BNP levels (<50 pg/ml) were observed in 4.9%, 14.0%, and 16.3% of patients with hospitalized HF, abnormal cardiac structure/function, or abnormal hemodynamics, respectively. A small proportion (0.1% to 1.1%) in each group had BNP levels below detection limits. Higher body mass index was the strongest predictor of unexpectedly low BNP. Exome sequencing did not reveal coding variation predicted to alter detection of BNP by clinical assays. ConclusionsA subset of patients with confirmed HF or cardiac dysfunction have unexpectedly low BNP levels. Obesity is the strongest correlate of unexpectedly low BNP levels. Our findings support the possible existence of NP deficiency, which may render some individuals more susceptible to volume or pressure overload.

Early detection of elevated cardiac biomarkers to optimise risk stratification in patients with COVID-19

ObjectiveRisk stratification is crucial to optimise treatment strategies in patients with COVID-19. We aimed to evaluate the impact on mortality of an early assessment of cardiac biomarkers in patients with...

Detection of B-type natriuretic peptide by establishing a low-cost and replicable fluorescence resonance energy transfer platform.

Aiming at the establishment of a sensitive and specific diagnostic method for early heart failure (HF), we developed a cost-effective fluorescence resonance energy transfer (FRET) platform for the detection of B-type natriuretic peptide (BNP), a characteristic biomarker of HF. Graphene oxide (GO) was selected as the FRET receptor in view of its advantages including commercial availability, low-cost and chemical stability, and dye-modified aptamer was used as the energy donor of FRET as well as in charge of the specific recognition of BNP. Based on the ON (strong emission) and OFF (quenching) states of FRET in the presence and absence of BNP, respectively, specific detection of BNP was achieved in the range 0.074-0.56pg/mL with a limit of detection as low as 45fg/mL (3σ). This FRET platform was applied to detect BNP in 45 blood samples to demonstrate its practicability in clinical diagnosis. Compared tothe commonly used Siemens method (chemiluminescence immunoassay, CLIA) in hospital, our approach is more accurate and specific for HF diagnosis with areas under the receiver operating characteristic curves of 0.869 (95% CI 0.733-1.00, P < 0.05) vs 0.850 (95% CI 0.703-0.997, P < 0.05) and specificity of 68.8% vs 65.6%. This platform is promising in early diagnosis of HF through ultrasensitive and specific detection of BNP. Graphical abstract To solve the clinical diagnostic problem for early heart failure (HF) which lacks sensitivity and specificity, we established a cost-effective and rapid fluorescence analysis method based on fluorescence resonance energy transfer (FRET) platform for the detection of B-type natriuretic peptide (BNP), a characteristic biomarker of HF.

Pyridinium porphyrins and AuNPs mediated bionetworks as SPR signal amplification tags for the ultrasensitive assay of brain natriuretic peptide

Extension of the self-assembled bionanonetworks into surface plasmon resonance (SPR) assay investigation provides an effective signal amplification approach. Wefabricated a bionetwork by nucleic acids, organic compounds, and supramolecular gold nanoparticles for ultrasensitive SPR detection of B-type natriuretic peptide (BNP). The SPR method was developed by a sandwich-type format of aptamer-target-antibody, and the aptamer-modified bionanonetworks induced localized SPR and large refractive index for different concentrations of the target BNP. The linear concentrationrange and limit of detection were 1-10,000pg/mL (R2 = 0.9852) and 0.3pg/mL respectively. The detection recovery wasin the range 92.13 to 108.69%. The approach embraces the following main advantages: (1) Cooperative double recognition was realized by calix[4]arenes for amino aptamers and pyridinium porphyrins. (2) The approach provided the specificity for supramolecular-based nanomaterials and a simple synthesis process via the ordered self-assembly under mild conditions. (3) The bionanonetworks endowed the SPR assay with signal amplification and stable determination for trace proteins. Therefore, it is expected that this study may offer a new SPR signal-amplified platform of organic-inorganic bionanonetworks to achieve sensitive, stable, and real-time determination. Graphical abstract Schematic of bionanonetwork based on porphyrin-mediated functionalized gold nanoparticles for SPR signal amplification to quantitatively detect BNP.

Analyte-resolved magnetoplasmonic nanocomposite to enhance SPR signals and dual recognition strategy for detection of BNP in serum samples

B-type natriuretic peptide (BNP) is a short peptide that is considered to be an important heart failure (HF)-related biomarker. Due to its low concentration in the blood and short half-life, the sensitive detection of BNP is a bottleneck for diagnosing patients at early stages of HF. In this paper, we report a facile surface plasmon resonance (SPR) sensor to measure BNP; the sensor is based on aptamer-functionalized Au nanoparticles (GNPs-Apt) and antibody-modified magnetoplasmonic nanoparticles (MNPs-Ab) to enable dual screening of BNP in complex environments. During sensing, BNP forms MNP-Ab/BNP/GNP-Apt nanoconjugates that can be rapidly separated from the complex sample by a magnet to avoid degradation within the analyte's half-life. The developed SPR biosensor shows high selectivity, a wide dynamic response range of BNP concentrations from 100 fg/mL to 10 ng/mL, and a low detection limit of 28.2 fg/mL (S/N = 3). Using the proposed sensor, BNP was successfully detected in clinical samples. Thus, the designed SPR biosensor provides a novel and sensitive sensing platform for BNP detection with potential applications in clinical practice.

Dual mode competitive electrochemical immunoassay for B-type natriuretic peptide based on GS/SnO2/polyaniline-Au and ZnCo2O4/N-CNTs

A sensitive dual mode competitive electrochemical immunosensor for the detection of B-type natriuretic peptide (BNP) was successfully fabricated, which based on differential pulse voltammetry (DPV) and amperometric i-t curve response modes. Polyaniline (PAN) and tin dioxide (SnO2) were loaded on graphene sheets (GS), which could effectively promote the electron transfer process, thereby amplifying the current signal and increasing the sensitivity of the immunosensor. To promote biocompatibility, gold nanoparticles (Au) were incorporated on GS/SnO2/PAN (GS/SnO2/PAN-Au). GS/SnO2/PAN-Au complex was gotten to act as the platform which could provide a clearly DPV signals. N-doped carbon nanotubes (N-CNTs) embellished by ZnCo2O4 quantum dots (ZnCo2O4/N-CNTs) with excellent catalytic properties for the reduction of H2O2 was gotten to act as the label of the antibody-BNP (Ab), providing an obviously current signal through amperometric i-t curve method. A large quantity of BNP could be stable loaded in the modified electrode via GS/SnO2/PAN-Au with excellent electrical conductivity and good biocompatibility, which could compete with target-BNP to combine Ab that labelled by ZnCo2O4/N-CNTs. Under the optimum conditions, the immunosensor exhibited remarkable analytical performance of a linear range from 0.01 pg/mL to 1 ng/mL with a detection limit of 3.4 fg/mL for quantitative detection of BNP (S/N = 3). This method was able to become a universal strategy for other biological detection.

B-Type Natriuretic Peptide (BNP) Detection Using Electrochemical Immunosensor Based on Sandwich ELISA with Horseradish Peroxidase-Tetramethylbenzidine System

A study of B-type natriuretic peptide (BNP) antigen as a good prognostic marker for patients with heart failure antigen detection employing an electrochemical immunosensor is described here. Monoclonal anti-BNP capture antibody was immobilized on streptavidin-modified SPCEs to increase the sensitivity of the assay. An anti-BNP detection antibody conjugated with horseradish peroxidase enzyme (HRP) and 3,3,5,5’-tetramethybezidine dihydrochloride (TMB) was used as a substrate, in connection with voltammetric technique was achieve by measuring the peak current. Incorporation of a streptavidin/biotin system resulted in a well-oriented antibody immobilization of the capture antibody and consequently enhanced the sensitivity of the assay. Several optimizations were performed to reduce background signals; the optimal concentration of anti-BNP detection antibody needed, the time of SPCEs were first blocked with glycine, incubated with various concentrations of BNP and HRP-conjugated anti-BNP detection antibody (0 to 100.0 ng/mL), followed by electrochemical measurement were investigated,. In conclusion, this immunosensor greatly shortened and convenient for detection of heart failure diagnosis in real serum samples.

High yield two-dimensional (2-D) polyaniline layer and its application in detection of B-type natriuretic peptide in human serum

The demand for ultrasensitive and inexpensive biosensors is always strong due to increasing healthcare related concerns. Herein, we developed a simple method to prepare uniform, reliable, high yield, and low-cost two-dimensional (2-D) polyaniline layer for biosensor applications. The 2-D PANI layer’s surface morphology led to a 46% increase in surface area compared to a flat 2-D surface. Due to this unique morphology and excellent semiconducting properties, the 2-D PANI layer exhibited ultrasensitive performance with excellent specificity on BNP biomarker detection in fixed Debye length condition, which is comparable to or even higher than 1-D nanostructure biosensors. In further Debye length investigation, we have observed signal changes that are varied from 8nA to 16nA with Debye length changes from 0.5nm to 3.3nm for constant BNP concentration. This result shows an improvement in device sensitivity over increasing Debye length, which conforms to Debye screening theory. With the high specificity of over 400 fold, the PANI layer was capable of monitoring significantly low BNP levels in human serum, as low as 50pg/mL. Our findings provide an opportunity for the realization of ultrasensitive and inexpensive biosensors for clinical use.

An index of central rather than general or peripheral adiposity is independently associated with tissue doppler indices of left ventricular diastolic dysfunction

Introduction: Measurement of B-type natriuretic peptide (BNP) or NT Pro-BNP has been advocated for cardiovascular disease (CVD) risk stratification. The purpose of this study is to assess the association between the presence of abnormal BNP/pro BNP and early detection of left ventricular hypertrophy (LVH) in asymptomatic hypertensive subjects with well controlled hypertension (HTN). Methods: We evaluated 2230 asymptomatic subjects aged 23-80 years, who underwent screening for CVD risk stratification using Early CVD Risk Score (ECVDRS), also known as Rasmussen Risk Score (RRS). ECVDRS consists of 10 non-invasive tests: large (C1) and small (C2) artery stiffness, blood pressure (BP) at rest and post mild exercise (PME), Carotid Intima Media Thickness (CIMT), abdominal aorta ultrasound, retinal photography, microalbuminuria, electrocardiogram (ECG), left ventricular ultrasound, and BNP/Pro-BNP. Results: Among the 2230 asymptomatic subjects, we analyzed 226 hypertensive subjects who are currently treated for HTN and are well controlled. To test the hypothesis that asymptomatic subjects with LVH have a significantly higher BNP/ProBNP values than those without LVH despite HTN control, we used a Chi-square tests to test the independence between patients with or without LVH regarding their BNP/ProBNP status coded as being normal or abnormal. The prevalence of LVH was 35% (n1⁄480) and the finding of the Chi-square test was highly significant; the proportion of abnormal LVH was 0.28 and 0.53 respectively with normal vs elevated BNP/ProBNP for the patients in our study, c; (1, N 1⁄4 226) 1⁄4 13.370, p 1⁄40.0004. Conclusions: Abnormal BNP/pro-BNP levels were significantly associated with echo-determined LVH in asymptomatic hypertensive subjects despite of having well controlled HTN. Based on these findings, we propose that measurement of ProBNP/BNP in hypertensive subjects can serve as a useful screening tool for further risk stratification and justify appropriate treatment and follow up to avert the progression of structural abnormality such as LVH, which is known to be associated with significant morbidity and mortality. ‘‘Prevention is better than cure’’.

Abnormal BNP in asymptomatic well controlled hypertensive subjects is a novel marker associated with early cardiovascular structural abnormalities, i.e. left ventricular hypertrophy

Introduction: Measurement of B-type natriuretic peptide (BNP) or NT Pro-BNP has been advocated for cardiovascular disease (CVD) risk stratification. The purpose of this study is to assess the association between the presence of abnormal BNP/pro BNP and early detection of left ventricular hypertrophy (LVH) in asymptomatic hypertensive subjects with well controlled hypertension (HTN). Methods: We evaluated 2230 asymptomatic subjects aged 23-80 years, who underwent screening for CVD risk stratification using Early CVD Risk Score (ECVDRS), also known as Rasmussen Risk Score (RRS). ECVDRS consists of 10 non-invasive tests: large (C1) and small (C2) artery stiffness, blood pressure (BP) at rest and post mild exercise (PME), Carotid Intima Media Thickness (CIMT), abdominal aorta ultrasound, retinal photography, microalbuminuria, electrocardiogram (ECG), left ventricular ultrasound, and BNP/Pro-BNP. Results: Among the 2230 asymptomatic subjects, we analyzed 226 hypertensive subjects who are currently treated for HTN and are well controlled. To test the hypothesis that asymptomatic subjects with LVH have a significantly higher BNP/ProBNP values than those without LVH despite HTN control, we used a Chi-square tests to test the independence between patients with or without LVH regarding their BNP/ProBNP status coded as being normal or abnormal. The prevalence of LVH was 35% (n1⁄480) and the finding of the Chi-square test was highly significant; the proportion of abnormal LVH was 0.28 and 0.53 respectively with normal vs elevated BNP/ProBNP for the patients in our study, c; (1, N 1⁄4 226) 1⁄4 13.370, p 1⁄40.0004. Conclusions: Abnormal BNP/pro-BNP levels were significantly associated with echo-determined LVH in asymptomatic hypertensive subjects despite of having well controlled HTN. Based on these findings, we propose that measurement of ProBNP/BNP in hypertensive subjects can serve as a useful screening tool for further risk stratification and justify appropriate treatment and follow up to avert the progression of structural abnormality such as LVH, which is known to be associated with significant morbidity and mortality. ‘‘Prevention is better than cure’’.

Ultrasensitive and Ultrawide Range Detection of a Cardiac Biomarker on a Surface Plasmon Resonance Platform

One of the main challenges in the development of new analytical platforms for ultrasensitive bioaffinity detection is jointly achieving a wide dynamic range in target analyte concentration, especially for approaches that rely on multistep processes as a part of the signal amplification mechanism. In this paper, a new surface-based sandwich assay is introduced for the direct detection of B-type natriuretic peptide (BNP), an important biomarker for cardiac failure, at concentrations ranging from 1 aM to 500 nM. This was achieved using nanoparticle-enhanced surface plasmon resonance (SPR) where a DNA aptamer is immobilized on a chemically modified gold surface in conjunction with the specific adsorption of antiBNP coated gold nanocubes in the presence of the biomarker target. A concentration detection range greater than eleven orders of magnitude was achieved through dynamic control of only the secondary nanoparticle probe concentration. Furthermore, detection at low attomolar concentrations was also achieved in undiluted human serum.

Phenotypic Screening with Human iPS Cell–Derived Cardiomyocytes: HTS-Compatible Assays for Interrogating Cardiac Hypertrophy

A major hurdle for cardiovascular disease researchers has been the lack of robust and physiologically relevant cell-based assays for drug discovery. Derivation of cardiomyocytes from human-induced pluripotent stem (iPS) cells at high purity, quality, and quantity enables the development of relevant models of human cardiac disease with source material that meets the demands of high-throughput screening (HTS). Here we demonstrate the utility of iPS cell–derived cardiomyocytes as an in vitro model of cardiac hypertrophy. Exposure of cardiomyocytes to endothelin 1 (ET-1) leads to reactivation of fetal genes, increased cell size, and robust expression of B-type natriuretic peptide (BNP). Using this system, we developed a suite of assays focused on BNP detection, most notably a high-content imaging-based assay designed for phenotypic screening. Miniaturization of this assay to a 384-well format enabled the profiling of a small set of tool compounds known to modulate the hypertrophic response. The assays described here provide consistent and reliable results and have the potential to increase our understanding of the many mechanisms underlying this complex cardiac condition. Moreover, the HTS-compatible workflow allows for the incorporation of human biology into early phases of drug discovery and development.