Multi-marker diagnosis method for early Hepatocellular Carcinoma based on surface plasmon resonance

The potential of a novel enzyme-based surface plasmon resonance biosensor for direct detection of dopamine

Dopamine is one of the significant neurotransmitters and its monitoring in biological fluids is a critical issue in healthcare and modern biomedical technology. Here, we have developed a dopamine biosensor based on surface plasmon resonance (SPR). For this purpose, the carboxymethyl dextran SPR chip was used as a surface to immobilize laccase as a bioaffinity recognition element. Data analysis exhibited that the acidic pH value is the optimal condition for dopamine interaction. Calculated kinetic affinity (KD) (48,545 nM), obtained from a molecular docking study, showed strong association of dopamine with the active site of laccase. The biosensor exhibited a linearity from 0.01 to 189 μg/ml and a lower detection limit of 0.1 ng/ml (signal-to-noise ratio (S/N) = 3) that is significantly higher than the most direct dopamine detecting sensors reported so far. Experiments for specificity in the presence of compounds that can co-exist with dopamine detection such as ascorbic acid, urea and L-dopa showed no significant interference. The current dopamine biosensor with high sensitivity and specificity, represent a novel detection tool that offers a label-free, simple procedure and cost effective monitoring system.

Decomposition Mueller matrix polarimetry for enhanced miRNA detection with antimonene-based surface plasmon resonance sensor and DNA-linked gold nanoparticle signal amplification

A decomposition Mueller matrix method is proposed for detection of miRNA and enhanced by using a surface plasmon resonance (SPR). In the proposed approach, a Mueller matrix decomposition method is employed to extract the linear birefringence (LB) and circular dichroism (CD) properties of the miRNA sample. The accuracy of the LB and CD measurements is enhanced through the use of a high-resolution antimonene-based SPR prism coupler with DNA-linked gold nanoparticles (AuNPs). The feasibility of the proposed method is demonstrated by measuring the LB orientation angle (α) and CD property (R) of two miRNA aqueous solutions (hsa-miR-125-5p and hsa-miR-21-5p) over the concentration range of 0∼1000 fM in both cases. The results show that, for both samples, α and R vary linearly with the change in the miRNA concentration. Furthermore, the values of α and R obtained for the two samples are quantifiably different, and hence the selectivity of the proposed SPR sensor is confirmed. Overall, the results highlight the potential of the proposed sensor as a valuable tool for miRNA detection with prospective applications in cancer diagnosis.

Multiplexed miRNA and Protein Analysis Using Digital Quantitative PCR in Microwell Arrays

Proteins and microRNAs (miRNAs) act in tandem within biological pathways to regulate cellular functions, and their misregulation has been correlated to numerous diseases. Because of their interconnectedness, both miRNAs and proteins must be evaluated together to obtain accurate insights into the molecular pathways of pathogenesis. However, few analytical techniques can measure both classes of biomolecules in parallel from a single biological sample. Here, microfluidic digital quantitative PCR (dqPCR) was developed to simultaneously quantify miRNA and protein targets in a multiplexed assay using a single detection chemistry. This streamlined analysis was achieved by integrating base-stacking PCR and immuno-PCR in a microfluidic array platform. Analyses of let-7a (miRNA) and IL-6 (protein) were first optimized separately to identify thermocycling and capture conditions amenable to both biomolecules. Singleplex dqPCR studies exhibited the expected digital signals and quantification cycles for both analytes over a range of concentrations. Multiplexed analyses were then conducted to quantify both let-7a and IL-6 with high sensitivity (LODs ∼ 3 fM) over a broad dynamic range (5-5000 fM) using only standard PCR reagents. This multiplexed dqPCR was then translated to the analysis of HEK293 cell lysate, where endogenous let-7a and IL-6 were measured simultaneously without sample purification or pretreatment. Collectively, these studies demonstrate that the integration of BS-PCR and immuno-PCR achieves a sensitive and streamlined approach for multiplexed analyses of miRNAs and proteins, which will enable researchers to gain better insights into disease pathogenesis in future applications.

Metabolomics and network analysis uncovered profound inflammation-associated alterations in hepatitis B virus-related cirrhosis patients with early hepatocellular carcinoma

Patients with hepatitis B virus (HBV)-related liver cirrhosis (LC) are at high risk for hepatocellular carcinoma (HCC). Limitations in the early detection of HCC give rise to poor survival in this high-risk population. Here, we performed comprehensive metabolomics on health individuals and HBV-related LC patients with and without early HCC. Compared to non-HCC patients (N = 108) and health controls (N = 80), we found that patients with early HCC (N = 224) exhibited a specific plasma metabolome map dominated by lipid alterations, including lysophosphatidylcholines, lysophosphatidic acids and bile acids. Pathway and function network analyses indicated that these metabolite alterations were closely associated with inflammation responses. Using multivariate regression and machine learning approaches, we identified a five-metabolite combination that showed significant performances in differentiating early-HCC from non-HCC than α-fetoprotein (area under the curve values, 0.981 versus 0.613). At metabolomic levels, this work provides additional insights of metabolic dysfunction related to HCC progressions and demonstrates the plasma metabolites might be measured to identify early HCC in patients with HBV-related LC.

A simple, sensitive, label-free electrochemical immunosensor based on the chitosan-coated silver/cerium oxide (CS@Ag/CeO2) nanocomposites for the detection of alpha-fetoprotein (AFP)

Metal oxide-based sensors have the benefit of inexpensive, quick response, and high sensitivity in detecting specific biological species. In this article, a simple electrochemical immunosensor was fabricated using antibody-chitosan coated silver/cerium oxide (Ab-CS@Ag/CeO₂) nanocomposites on a gold electrode for sensitive alpha-fetoprotein (AFP) diagnosis in human serum samples. Successfully synthesis of AFP antibody-CS@Ag/CeO₂conjugates was confirmed through Fourier transform infrared spectra of the prototype. The amine coupling bond chemistry was then used to immobilize the resultant conjugate on a gold electrode surface. It was observed that the interaction of the synthesized Ab-CS@Ag/CeO₂nanocomposites with AFP prevented an electron transfer and reduced the voltammetric Fe(CN)₆^3-/4-peak current, which was proportional to the amount of AFP. The linear ranges of AFP concentration were found from 10^-12-10^-6g.ml^-1. The limit of detection was calculated using the calibration curve and came out to be 0.57 pg.ml^-1. The designed label-free immunosensor successfully detected AFP in human serum samples. As a result, the resulting immunosensor is a promising sensor plate form for AFP detection and could be used in clinical bioanalysis.

Mass Spectrometric Multiplex Detection of MicroRNA and Protein Biomarkers for Liver Cancer

The occurrence of cancers is often accompanied by the abnormal expression of several sorts of biomarkers (e.g., nucleic acids and proteins). The multiplex assessment of them would substantially aid in the early detection and precise diagnosis, which is often hampered by their different detection schemes, different reaction matrix and reagents, and spectral overlapping. Herein, we propose a simple and sensitive mass spectrometric method for the multiplex detection of nucleic acid and protein, in which liver cancer-related biomarkers miRNA 223 and alpha-fetoprotein (AFP) were selected as model analytes. The self-amplification effect of metal atom-based nanoparticle probes can provide high sensitivity in complex serum samples without any additional amplification procedure. The detection limits for the simultaneous detection of miRNA 223 and AFP were 103 (2.1 pM) and 219 amol (0.15 ng/mL), respectively, with high specificity and selectivity. The proposed method is potentially useful for the rapid screening of cancers.

An ultrasensitive immunosensor based on cellulose nanofibrils/polydopamine/Cu-Ag nanocomposite for the detection of AFP

In this work, an ultrasensitive immunosensor for amperometric determination of alpha-fetoprotein (AFP) was developed utilizing Ag and Cu nanoparticles on polydopamine (PDA) functionalized cellulose nanofibrils (CNFs) composite (CNFs/PDA/Cu-Ag) as signal amplifier. PDA was first prepared by self-polymerizing of dopamine, and then was adsorbed on CNFs. The obtained CNFs/PDA was applied as substrate to electrolessly deposit Cu-Ag nanoparticles, using NaBH₄ as reducing agent. The structure and morphology of the synthesized CNFs/PDA/Cu-Ag nanocomposite were analyzed through Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, scanning electron microscopy, particle size analyzer and transmission electron microscopy. The CNFs/PDA/Cu-Ag modified glassy carbon electrode can fix AFP antibody (Ab), and further capture AFP specifically. Electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the assembly process of immunosensor. The immunoreaction was amplified by electrocatalytical reduction of H₂O₂ on Cu-Ag nanoparticles, through which AFP was quantitatively detected. The developed sensor exhibits wide linear range of 0.01-100 ng mL^-1 (R² = 0.9963) with low detection limit of 4.27 pg mL^-1 (S/N = 3). In addition, it has been used for the detection of AFP in human serum, manifesting its preeminent application prospect in early liver cancer diagnosis.

The role of miRNA125b in the progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common tumours worldwide, and identifying markers related to HCC is an important area of research. As a microRNA (miRNA), miRNA125b (miR-125b) plays an important role in the prediction and prognosis of HCC. In the past 10 years, with increasing research on miR-125b and HCC, the molecular mechanism of its relationship with the development of HCC has been elucidated. MiR-125b inhibits the development of HCC and is highly accurate in predicting HCC and is therefore a valuable predictive marker of HCC. This article summarizes the clinical application of miR-125b in HCC and the potential mechanism of its involvement in the progression of HCC.

Double-Antibody Sandwich Immunoassay and Plasmonic Coupling Synergistically Improved Long-Range SPR Biosensor with Low Detection Limit

A long-range surface plasmonic resonance (LR-SPR) biosensor modified with double-antibody sandwich immunoassay and plasmonic coupling is demonstrated for human-immunoglobulin G detection with a low limit of detection (LOD). The double-antibody sandwich immunoassay dramatically changes the average refractive index of the medium layer on the sensor surface. The near-field electron coupling between the localized surface plasmon and the long-range surface plasmon leads to a significant perturbation of the evanescent field. The large penetration depth and the long propagation distance of the long-range surface plasmonic waves facilitate the LR-SPR sensor in the detection of biological macromolecules. The unique light absorption characteristic of the nanocomposite material in the sensor provides the in situ self-compensation for the disturbance. Therefore, besides the inherent advantages of optical fiber sensors, the developed biosensor can realize the detection of biomolecules with high sensitivity, low LOD and high accuracy and reliability. Experimental results demonstrate that the LOD of the biosensor is as low as 0.11 μg/mL in the detection of the phosphate-buffered saline sample, and the spike-and-repetition rate is 105.56% in the detection of the real serum sample, which partly shows the practicability of the biosensor. This indicates that the LR-SPR biosensor provides better response compared with existing similar sensors and can be regarded as a valuable method for biochemical analysis and disease detection.

Non-Coding RNA-Based Biosensors for Early Detection of Liver Cancer

Primary liver cancer is an aggressive, lethal malignancy that ranks as the fourth leading cause of cancer-related death worldwide. Its 5-year mortality rate is estimated to be more than 95%. This significant low survival rate is due to poor diagnosis, which can be referred to as the lack of sufficient and early-stage detection methods. Many liver cancer-associated non-coding RNAs (ncRNAs) have been extensively examined to serve as promising biomarkers for precise diagnostics, prognostics, and the evaluation of the therapeutic progress. For the simple, rapid, and selective ncRNA detection, various nanomaterial-enhanced biosensors have been developed based on electrochemical, optical, and electromechanical detection methods. This review presents ncRNAs as the potential biomarkers for the early-stage diagnosis of liver cancer. Moreover, a comprehensive overview of recent developments in nanobiosensors for liver cancer-related ncRNA detection is provided.

Recent Advancements in Receptor Layer Engineering for Applications in SPR-Based Immunodiagnostics

The rapid progress in the development of surface plasmon resonance-based immunosensing platforms offers wide application possibilities in medical diagnostics as a label-free alternative to enzyme immunoassays. The early diagnosis of diseases or metabolic changes through the detection of biomarkers in body fluids requires methods characterized by a very good sensitivity and selectivity. In the case of the SPR technique, as well as other surface-sensitive detection strategies, the quality of the transducer-immunoreceptor interphase is crucial for maintaining the analytical reliability of an assay. In this work, an overview of general approaches to the design of functional SPR-immunoassays is presented. It covers both immunosensors, the design of which utilizes well-known and often commercially available substrates, as well as the latest solutions developed in-house. Various approaches employing chemical and passive binding, affinity-based antibody immobilization, and the introduction of nanomaterial-based surfaces are discussed. The essence of their influence on the improvement of the main analytical parameters of a given immunosensor is explained. Particular attention is paid to solutions compatible with the latest trends in the development of label-free immunosensors, such as platforms dedicated to real-time monitoring in a quasi-continuous mode, the use of in situ-generated receptor layers (elimination of the regeneration step), and biosensors using recombinant and labelled protein receptors.

Enhanced performance of a surface plasmon resonance-based immunosensor for the detection of glycocholic acid

The concentration of glycocholic acid (GCA) in urine and blood is an important biomarker for liver cancer. Monitoring of GCA depends to a large extent on the availability of appropriate analytical techniques. In this work, based on the immobilization of GCA-OVA onto the sensor chip surface, a label-free competitive inhibition immunoassay for the determination of GCA with the surface plasmon resonance (SPR) technique was developed. The proposed SPR immunosensor is simple to prepare, recyclable and exhibits excellent sensitivity to GCA (a linear range of 13.3-119.4 ng mL^-1 and a limit of detection (LOD) of 2.5 ng mL^-1), which was 14 times lower than that of the traditional immunoassay. Excellent recoveries and correlation between these two methods were observed (R² = 0.995). Hence, it can be proved that the SPR immunosensor could be used to achieve rapid and sensitive quantitative detection of GCA in real urine samples and meet clinical needs.

Low-Fouling Substrates for Plasmonic Sensing of Circulating Biomarkers in Biological Fluids

The monitoring of biomarkers in body fluids provides valuable prognostic information regarding disease onset and progression. Most biosensing approaches use noninvasive screening tools and are conducted in order to improve early clinical diagnosis. However, biofouling of the sensing surface may disturb the quantification of circulating biomarkers in complex biological fluids. Thus, there is a great need for antifouling interfaces to be designed in order to reduce nonspecific adsorption and prevent inactivation of biological receptors and loss of sensitivity. To address these limitations and enable their application in clinical practice, a variety of plasmonic platforms have been recently developed for biomarker analysis in easily accessible biological fluids. This review presents an overview of the latest advances in the design of antifouling strategies for the detection of clinically relevant biomarkers on the basis of the characteristics of biological samples. The impact of nanoplasmonic biosensors as point-of-care devices has been examined for a wide range of biomarkers associated with cancer, inflammatory, infectious and neurodegenerative diseases. Clinical applications in readily obtainable biofluids such as blood, saliva, urine, tears and cerebrospinal and synovial fluids, covering almost the whole range of plasmonic applications, from surface plasmon resonance (SPR) to surface-enhanced Raman scattering (SERS), are also discussed.

Circulating MicroRNA-122 for the Diagnosis of Hepatocellular Carcinoma: A Meta-Analysis

Background

Circulating microRNA-122 (miR-122) has been recognized as a marker of hepatocellular carcinoma (HCC). The current meta-analysis was performed to quantitatively evaluate the diagnostic performance of circulating miR-122 for HCC.

Methods

Related studies that evaluated the diagnostic performance of circulating miR-122 determined from pathophysiological examination for HCC were obtained by systematic searches of the PubMed and Embase databases. A randomized fixed effects model was applied according to the heterogeneity among studies. The pooled sensitivity, specificity, and area under the summary receiver operating characteristic curve (AUC) were calculated to evaluate the diagnostic accuracy. Publication bias was detected by Deeks' funnel plot asymmetry test.

Results

Thirteen studies providing data for 920 HCC patients and 1217 controls were included in the meta-analysis. The pooled sensitivities, specificities, and AUCs of serum miR-122 were 0.76, 0.75, and 0.82, respectively, for discriminating HCC patients from overall controls; 0.85, 0.83, and 0.91, respectively, for discriminating HCC patients from healthy controls; 0.79, 0.82, and 0.87, respectively, for discriminating HCC from HBV or HCV infection; and 0.65, 0.75, and 0.74, respectively, for discriminating HCC from liver cirrhosis or dysplastic nodule formation. No significant publication bias was detected.

Conclusions

Serum miR-122 confers moderate efficacy for discriminating HCC patients from healthy controls or patients with HBV or HCV infection, but not for discriminating HCC patients from those with liver cirrhosis or dysplastic nodule formation.