Troponin I as a Biomarker for Early Detection of Acute Myocardial Infarction

An overview about biomarkers in breast cancer: Insights into the diagnostic and prognostic significance

Breast cancer (BC) is one of the most significant neoplasms globally due to its high incidence and mortality, particularly among females. As a highly heterogeneous pathology, biomarkers are essential for characterizing specific tumors. Currently, several biological processes are well-described in the context of this neoplasm, such as alterations in BRCA1/2, HER, and pathways involving estrogen and progesterone hormone receptors. These studies have enabled the use of these findings as more precise methods for diagnosis, prognosis, and treatment. However, beyond patients who do not exhibit these classic markers, some individuals within the same risk group respond differently to treatment. Therefore, the search for biological markers that can improve diagnosis, aid in stratification, or serve as therapeutic targets is continuous and urgent. Genetic signatures have led to molecular tests currently used in clinical practice, though certain limitations persist. Understanding genetic and epigenetic mechanisms facilitates the identification of potential biomarkers. Biomarker targets must undergo experimental and clinical trials on samples of significant size before reaching clinical utility. In this review, we compile the classical markers and describe the potential use of other markers associated with the biological processes of this neoplasm.

An integrated magnetoimpedance biosensor microfluidic magnetic platform for the evaluation of the cardiac marker cTnI

An integrated magnetoimpedance (MI) biosensor microfluidic magnetic platform was proposed for the evaluation of the cardiac marker, cardiac troponin I (cTnI). This bioanalyte evaluation platform mainly comprised three external permanent magnets (PMs), one MI element, two peelable SiO2 film units and a microfluidic chip (MFC). The MI element was made of micro-electro-mechanical system (MEMS)-based multilayered [Ti (6 nm)/FeNi (100 nm)]5/Cu (400 nm)/[Ti (6 nm)/FeNi (100 nm)]5 thin films and designed as meander structures with closed magnetic flux. The MFC was fabricated using 3D printing and inverted molding techniques, designed with a solution by mixing the reaction region, magnetic separation region and detection region. Peelable SiO2 film units with the same size as the MI sensing element were used as the immunoreactivity interface of the bioanalytes. Two large PMs were placed directly below the MI sensing unit to provide a bias magnetic field, and the smaller PM was embedded in MCF for magnetic separation function. Different concentrations of the biological target (cTnI antigen)-, PBS buffer-, and Dynabeads-labeled polyclonal cTnI antibody solution were injected sequentially into the MCF. After immunoreactivity and magnetic separation, a classical sandwich immunoreaction process occurred on the surface of the monoclonal antibody-modified SiO2 film via self-assembling process in the reaction region of the MFC. The fundamental principle for evaluation of cTnI was based on variations of the MI signal under different concentrations of the biological target coupled with different numbers of Dynabeads. It was demonstrated that the mentioned MI-based magnetic platform could perform quantitative detection analyses over a range of cTnI concentrations (lowest concentration = 0.1 ng mL-1 and highest concentration = 100 ng mL-1). The proposed MI-based magnetic platform provides a sensitive, reliable, stable and reusable bioanalytical platform, and it has potential in future biomedical applications.

An ultrasensitive electrochemical immunosensor based on meso-PdN NCs and Au NPs/N-CNTs for quantitative cTnI detection

Electrochemical immunosensors have gained considerable attention in detecting human disease markers due to their excellent specificity, high sensitivity, and facile operation. Herein, a rational-designed sandwich-type electrochemical immunosensor is constructed for the sensitive detection of cardiac troponin I (cTnI) using nitrogen-doped carbon nanotubes loaded with gold nanoparticles (Au NPs/N-CNTs) as substrate and highly active mesoporous palladium-nitrogen nanocubes (meso-PdN NCs) as secondary antibody markers. Benefitting from its large specific surface area (638.04 m2 g-1) and high nitrogen content, novel polydopamine (PDA)/ halloysite nanotubes (HNTs) hybrid derived one-dimensional (1D) N-CNTs can provide more binding sites for the in-situ growth of Au NPs to connect Ab1. Furthermore, as an ideal substrate material, Au NPs/N-CNTs exhibit finely tuned mesoporous structures and outstanding conductivity, which facilitate the mass and electron transfer during the electrocatalysis process. Besides, highly concave surfaces and crystalline mesopores of meso-PdN NCs expose more surfaces and crevices, providing abundant reactive sites for H2O2 reduction. Remarkably, the as-obtained immunosensor presented a wide linear range (from 10 fg mL-1 to 100 ng mL-1) and an excellent low detection limit (9.85 fg mL-1). This study may offer new insights into the precise fabrication of efficient electrochemical immunosensors for various clinical diagnosis applications.

Unveiling the Potential of Migrasomes: A Machine-Learning-Driven Signature for Diagnosing Acute Myocardial Infarction

BACKGROUND

Recent studies have demonstrated that the migrasome, a newly functional extracellular vesicle, is potentially significant in the occurrence, progression, and diagnosis of cardiovascular diseases. Nonetheless, its diagnostic significance and biological mechanism in acute myocardial infarction (AMI) have yet to be fully explored.

METHODS

To remedy this gap, we employed an integrative machine learning (ML) framework composed of 113 ML combinations within five independent AMI cohorts to establish a predictive migrasome-related signature (MS). To further elucidate the biological mechanism underlying MS, we implemented single-cell RNA sequencing (scRNA-seq) of cardiac Cd45+ cells from AMI-induced mice. Ultimately, we conducted mendelian randomization (MR) and molecular docking to unveil the therapeutic effectiveness of MS.

RESULTS

MS demonstrated robust predictive performance and superior generalization, driven by the optimal combination of Stepglm and Lasso, on the expression of nine migrasome genes (BMP1, ITGB1, NDST1, TSPAN1, TSPAN18, TSPAN2, TSPAN4, TSPAN7, TSPAN9, and WNT8A). Notably, ITGB1 was found to be predominantly expressed in cardiac macrophages in AMI-induced mice, mechanically regulating macrophage transformation between anti-inflammatory and pro-inflammatory. Furthermore, we showed a positive causality between genetic predisposition towards ITGB1 expression and AMI risk, positioning it as a causative gene. Finally, we showed that ginsenoside Rh1, which interacts closely with ITGB1, could represent a novel therapeutic approach for repressing ITGB1.

CONCLUSIONS

Our MS has implications in forecasting and curving AMI to inform future diagnostic and therapeutic strategies for AMI.

Wearable biosensors in cardiovascular disease

This review provides a comprehensive overview of the latest advancements in wearable biosensors, emphasizing their applications in cardiovascular disease monitoring. Initially, the key sensing signals and biomarkers crucial for cardiovascular health, such as electrocardiogram, phonocardiography, pulse wave velocity, blood pressure, and specific biomarkers, are highlighted. Following this, advanced sensing techniques for cardiovascular disease monitoring are examined, including wearable electrophysiology devices, optical fibers, electrochemical sensors, and implantable cardiac devices. The review also delves into hydrogel-based wearable electrochemical biosensors, which detect biomarkers in sweat, interstitial fluids, saliva, and tears. Further attention is given to flexible electronics-based biosensors, including resistive, capacitive, and piezoelectric force sensors, as well as resistive and pyroelectric temperature sensors, flexible biochemical sensors, and sensor arrays. Moreover, the discussion extends to polymer-based wearable sensors, focusing on innovations in contact lens, textile-type, patch-type, and tattoo-type sensors. Finally, the review addresses the challenges associated with recent wearable biosensing technologies and explores future perspectives, highlighting potential groundbreaking avenues for transforming wearable sensing devices into advanced diagnostic tools with multifunctional capabilities for cardiovascular disease monitoring and other healthcare applications.

AlphaLISA-Based Immunoassay for Detection of Troponin T in Serum of Patients with Acute Myocardial Infarction

Survival and prognosis of patients with acute myocardial infarction (AMI) are highly dependent on rapid and accurate diagnosis of myocardial damage. Troponin T is the primary diagnostic biomarker and is widely used in clinical practice. Amplified luminescent proximity homogeneous assay (AlphaLISA) may provide a solution to rapidly detect a small amount of analyte through molecular interactions between special luminescent donor beads and acceptor bead. Here, a double-antibody sandwich assay was introduced into AlphaLISA for rapid detection for early diagnosis of AMI and disease staging evaluation. The performance of the assay was evaluated. The study found that the cTnT assay has a linear range of 48.66 to 20,000 ng/L with a limit of detection of 48.66 ng/L. In addition, the assay showed no cross-reactivity with other classic biomarkers of myocardial infarction and was highly reproducible with intra- and inter-batch coefficients of variation of less than 10%, notably, only 3 min was taken, which is particularly suitable for clinical diagnosis. These results suggest that our method can be conveniently applied in the clinic to determine the severity of the patient's condition.

A Portable Readout System for Biomarker Detection with Aptamer-Modified CMOS ISFET Array

Biosensors based on ion-sensitive field effect transistors (ISFETs) combined with aptamers offer a promising and convenient solution for point-of-care testing applications due to the ability for fast and label-free detection of a wide range of biomarkers. Mobile and easy-to-use readout devices for the ISFET aptasensors would contribute to further development of the field. In this paper, the development of a portable PC-controlled device for detecting aptamer-target interactions using ISFETs is described. The device assembly allows selective modification of individual ISFETs with different oligonucleotides. Ta2O5-gated ISFET structures were optimized to minimize trapped charge and capacitive attenuation. Integrated CMOS readout circuits with linear transfer function were used to minimize the distortion of the original ISFET signal. An external analog signal digitizer with constant voltage and superimposed high-frequency sine wave reference voltage capabilities was designed to increase sensitivity when reading ISFET signals. The device performance was demonstrated with the aptamer-driven detection of troponin I in both reference voltage setting modes. The sine wave reference voltage measurement method reduced the level of drift over time and enabled a lowering of the minimum detectable analyte concentration. In this mode (constant voltage 2.4 V and 10 kHz 0.1Vp-p), the device allowed the detection of troponin I with a limit of detection of 3.27 ng/mL. Discrimination of acute myocardial infarction was demonstrated with the developed device. The ISFET device provides a platform for the multiplexed detection of different biomarkers in point-of-care testing.

Dual-Encoded Affinity Microbead Signature Combinatorial Profiling for Acute Myocardial Infarction High-Sensitivity Diagnosis

The early diagnosis of acute myocardial infarction (AMI) is dependent on the combined feedback of multiple cardiac biomarkers. However, it remains challenging to precisely detect multicardiac biomarkers in complex blood early due to the lack of sensitive and specific diagnostic indicators and the low abundance and small size of associated biomarkers with high specificity (such as microRNAs). To make matters worse, spectral overlap significantly limits the multiplex analysis of cardiac biomarkers by fluorescent probes, leading to bias in the diagnosis of myocardial infarction. Herein, we developed a method for simultaneous detection of miRNAs and protein biomarkers using size- and color-coded microbeads that carry signature for target capture. We also constructed a microfluidic chip with different spacer arrays that segregate these microbeads in different chip regions according to their size to produce signature signals, indicating the level of different biomarkers. The signals on the microbeads were hugely amplified by catalytic hairpin assembly and rolling circle amplification. Notably, this strategy enables the simultaneous and in situ sensitive profiling of six kinds of biomarkers via adding two different fluorescent labels, removing the limitations of spectral overlap. We envision that the strategy has great potential for application in clinical diagnosis for AMI.

Cardiospecific Troponins as Laboratory Biomarkers of Myocardial Cell Injury in Hypertension: A Mini-Review

To date, it is well known that a significant number of diseases of cardiovascular genesis (coronary heart disease, myocardial infarction, cardiomyopathy, Takotsubo syndrome, heart failure, etc.) and extra-cardiac genesis (renal failure, chronic obstructive pulmonary disease, sepsis, diabetes mellitus, etc.) cause injury to contractile cells of the heart muscle (myocardial cells). The most sensitive and specific criteria for proving myocardial cell injury are cardiospecific troponins (CSTns) - CSTnI and CSTnT. According to the current clinical recommendations of the European, American, and Russian Cardiological Communities, CSTnI and CSTnT are the main biomarkers for early diagnosis of myocardial infarction. Hypertension is one of the most dangerous and common risk factors for the development of cardiovascular pathologies and is associated with a high risk of dangerous cardiovascular complications. Therefore, there is an urgent need to search for new biomarkers for the timely assessment of the prognosis of patients with hypertension. This mini-review aims to substantiate the possibilities of using the cardiomarkers (CSTnI and CSTnT) to assess the prognosis of patients suffering from hypertension and to discuss potential mechanisms that cause injury to myocardial cells and increase serum levels of CSTnI and CSTnT. This is a narrative mini-review, which was prepared using the following databases: Pubmed/Medline, PubMed Central, Embase, Scopus, and Web of Science. The following keywords were used in the literature search: "myocardial cells", "injury", "damage", and "hypertension" in combination with the terms "mechanisms of injury" "predictive significance", "cardiac troponins", or "cardiospecific troponins".

An Isobaric Labeling Approach to Enhance Detection and Quantification of Tissue-Derived Plasma Proteins as Potential Early Disease Biomarkers

The proteomic analysis of plasma holds great promise to advance precision medicine and identify biomarkers of disease. However, it is likely that many potential biomarkers circulating in plasma originate from other tissues and are only present in low abundances in the plasma. Accurate detection and quantification of low abundance proteins by standard mass spectrometry approaches remain challenging. In addition, it is difficult to link low abundance plasma proteins back to their specific tissues or organs of origin with confidence. To address these challenges, we developed a mass spectrometry approach based on the use of tandem mass tags (TMT) and a tissue reference sample. By applying this approach to nonhuman primate plasma samples, we were able to identify and quantify 820 proteins by using a kidney tissue homogenate as reference. On average, 643 ± 16 proteins were identified per plasma sample. About 58% of proteins identified in replicate experiments were identified both times. A ratio of 50 μg kidney protein to 10 μg plasma protein, and the use of the TMT label with the highest molecular weight (131) for the kidney reference yielded the largest number of proteins in the analysis, and identified low abundance proteins in plasma that are prominently found in the kidney. Overall, this methodology promises efficient quantification of plasma proteins potentially released from specific tissues, thereby increasing the number of putative disease biomarkers for future study.

Hypertension as One of the Main Non-Myocardial Infarction-Related Causes of Increased Cardiospecific Troponins: From Mechanisms to Significance in Current Medical Practice

It is well known that many pathological conditions of both cardiovascular diseases (CVDs) (coronary heart disease, myocardial infarction, arrhythmias, myocarditis, cardiomyopathy, etc.) and non-cardiac (sepsis, anemia, kidney diseases, diabetes mellitus, etc.) origin in the course of their development cause injury to contractile cardiac muscle cells - myocardial cells (MCs). One of the most sensitive and specific criteria for detecting MC injury are cardiospecific troponins (CTs), which are regulatory protein molecules that are released into the blood serum from MC upon their death or injury. Current methods for determining CTs are called high-sensitive ones, and their main advantage is a very low minimum detectable concentration (limit of detection) (average 1 - 10 ng/L or less), which allows early detection of minor MC injury at the earliest stages of CVDs, and therefore they can change the understanding of disease development mechanisms and open up new diagnostic possibilities. One of the most common and dangerous early diseases of the cardiovascular system is hypertension (HT). The novelty of this article lies in the discussion of a new diagnostic direction - predicting the risk of developing CVDs and their dangerous complications in patients with HT by determining the concentration of CTs. In addition, pathophysiological mechanisms underlying MC injury and the release of CTs into the bloodstream and the elimination of CTs into the urine are proposed. This information will contribute to additional fundamental and clinical research to verify the new diagnostic possibility of using CTs in clinical practice (for the management of patients with HT).

Prefab Hollow Glass Microsphere-Based Immunosensor with Liquid Crystal Sensitization for Acute Myocardial Infarction Biomarker Detection

Quantitative detection of cardiac troponin biomarkers in blood is an important method for clinical diagnosis of acute myocardial infarction (AMI). In this work, a whispering gallery mode (WGM) microcavity immunosensor based on a prefab hollow glass microsphere (HGMS) with liquid crystal (LC) sensitization was proposed and experimentally demonstrated for label-free cardiac troponin I-C (cTnI-C) complex detection. The proposed fiber-optic immunosensor has a simple structure; the tiny modified HGMS serves as the key sensing element and the microsample reservoir simultaneously. A sensitive LC layer with cTnI-C recognition ability was deposited on the inner wall of the HGMS microcavity. The arrangement of LC molecules is affected by the cTnI-C antigen-antibody binding in the HGMS, and the small change of the surface refractive index caused by the binding can be amplified owing to the birefringence property of LC. Using the annular waveguide of the HGMS, the WGMs were easily excited by the coupling scanning laser with a microfiber, and an all-fiber cTnI-C immunosensor can be achieved by measuring the resonant wavelength shift of the WGM spectrum. Moreover, the dynamic processes of the cTnI-C antigen-antibody binding and unbinding was revealed by monitoring the wavelength shift continuously. The proposed immunosensor with a spherical microcavity can be a cost-effective tool for AMI diagnosis.