Simultaneous quantitation of carbohydrate antigen 125 and carcinoembryonic antigen in human serum via time-resolved fluoroimmunoassay

The impact of neoadjuvant chemotherapy on the clinical efficacy and serum tumor marker levels in patients undergoing radical surgery for gastric cancer

The objective of this article is to study the impact of neoadjuvant chemotherapy (NAC) on the clinical efficacy and serum tumor marker levels in patients undergoing radical surgery for gastric cancer (GC). Thirty patients who underwent routine radical surgery for GC in our hospital from January 2020 to June 2021 were included in the control group. Thirty patients who underwent radical surgery for GC after receiving NAC from July 2021 to December 2022 were included in the observation group. The treatment outcomes of the observation group were assessed and analyzed. The surgical indicators, tumor markers, Karnofsky Performance Status (KPS), and occurrence of adverse reactions were compared between the 2 groups. Comparisons were made between the 2 groups in terms of surgical duration, number of lymph node dissections, intraoperative blood loss, time to postoperative ambulation, length of hospital stay, and time to postoperative passage of flatus (P > .05). The observation group had a higher proportion of R0 resection at the surgical margin compared to the control group (P < .05). The serum tumor markers of the 2 groups were compared before treatment (P > .05). After treatment, the levels of serum carcinoembryonic antigen, alpha-fetoprotein, cancer antigen 125, and carbohydrate antigen 72-4 decreased in both groups, and the observation group showed a greater reduction in these tumor marker levels compared to the control group (P < .05). The KPS scores of the 2 groups were compared before treatment (P > .05). After treatment, the KPS scores increased in both groups, with the observation group showing a higher improvement compared to the control group (P < .05). The overall incidence of adverse reactions, including incision infection, pleural effusion, pulmonary infection, intestinal obstruction, and gastric emptying disorders, was lower in the observation group (6.67%) compared to the control group (26.67%) (P < .05). The combination of NAC with radical surgery for GC is safe and feasible. It can significantly increase the R0 resection rate, effectively improve the levels of serum tumor markers, enhance patient's quality of life, and result in fewer surgical adverse reactions.

Highly sensitive electrochemical immunosensor based on electrodeposited platinum nanostructures confined in silica nanochannels for the detection of the carcinoembryonic antigen

In this study, we report a highly sensitive electrochemical immunosensor for carcinoembryonic antigen (CEA) detection based on the electrodeposited platinum nanoparticles (Pt NPs) confined in the ultrasmall nanochannels of vertically ordered mesoporous silica film (VMSF). VMSF bearing amine groups (NH2-VMSF) can be prepared on the indium tin oxide electrode surface via a one-step co-condensation route using an electrochemically assisted self-assembly method, which renders a strong electrostatic effect for [PtCl6]2- and leads to the spatial confinement of Pt NPs inside the silica nanochannels after electrodeposition. The external surface of NH2-VMSF is functionalized with CEA antibodies using glutaraldehyde as a coupling agent, resulting in an electrochemical immunosensing interface with good specificity for CEA detection. Under optimal experimental conditions, high affinity between the CEA antibody and CEA produces a steric hindrance effect for the accessibility of the electrochemical probe ([Fe(CN)6]3-) in the bulk solution to the underlying indium tin oxide surface, eventually resulting in the attenuated electrochemical signal and enabling the detection of the CEA with a wide linear range of 0.01 pg/mL∼10 ng/mL and a pretty low limit of detection of 0.30 fg/mL. Owing to the signal amplification ability of Pt NPs and the anti-biofouling property of NH2-VMSF, the as-prepared electrochemical immunosensor based on the Pt NPs@NH2-VMSF displays an accurate analysis of the CEA in human serum samples, holding significant promise for health monitoring and clinical diagnosis.

NIR-II fluorescent nanoprobe-labeled lateral flow biosensing platform: A high-performance point-of-care testing for carcinoembryonic antigen

Fluorescent lateral flow immunoassay (LFA) is one of the most common analytical platforms for point-of-care testing (POCT), which is capable of facile and early screening of biomarkers. Notably, fluorescent probes play a decisive role in analytical performances of LFA. Herein, we report a novel LFA based on the rare earth doped nanoparticles (RENPs) emitting in the second near-infrared (NIR-II) window for the detection of biomarkers, such as carcinoembryonic antigen (CEA). Benefiting from the dual fluorescent emission at NIR-II window, strong fluorescent penetration, low autofluorescence and excellent photostability of RENPs, this proposed NIR-II LFA displays a good linear relationship ranging from 1 to 320 ng mL^-1. The detection limit is as low as 0.37 ng mL^-1, which is of 13.5 times lower than the clinical cutoff value. Overall, NIR-II LFA biosensing platform based RENPs not only exhibits high sensitivity, accuracy and specificity, but also have characteristics of rapidity, simplicity and low cost. It holds high potential for early diagnosis of tumor biomarkers in POCT.

Gold nanoparticles-oxidized multi-walled carbon nanotubes as electrochemiluminescence immunosensors

Oxidized multi-walled carbon nanotube/nano-gold (AuNP-ox-MWCNT) composites with strong electrochemiluminescence (ECL) activity were applied to construct a new ECL immunosensor for the detection of carcinoembryonic antigen (CEA). The immunosensor showed a linear response range of 10-100 ng mL^-1 and detection limit of 0.76 ng mL^-1 (at a signal-to-noise ratio of 3). The as-developed immunosensor exhibited several advantages, including being simple to fabricate and being label free. The results indicated that ox-MWCNTs as a luminescent material have great application potential in analysis.

Ultrasensitive Point-of-Care Test for Tumor Marker in Human Saliva Based on Luminescence-Amplification Strategy of Lanthanide Nanoprobes

The point-of-care detection of tumor markers in saliva with high sensitivity and specificity remains a daunting challenge in biomedical research and clinical applications. Herein, a facile and ultrasensitive detection of tumor marker in saliva based on luminescence-amplification strategy of lanthanide nanoprobes is proposed. Eu2O3 nanocrystals are employed as bioprobes, which can be easily dissolved in acidic enhancer solution and transform into a large number of highly luminescent Eu3+ micelles. Meanwhile, disposable syringe filter equipped with nitrocellulose membrane is used as bioassay platform, which facilitates the accomplishment of detection process within 10 min. The rational integration of dissolution enhanced luminescent bioassay strategy and miniaturized detection device enables the unique lab-in-syringe assay of tumor marker like carcinoembryonic antigen (CEA, an important tumor marker in clinic diagnosis and prognosis of cancer) with a detection limit down to 1.47 pg mL-1 (7.35 × 10-15 m). Upon illumination with a portable UV flashlight, the photoluminescence intensity change above 0.1 ng mL-1 (0.5 × 10-12 m) of CEA can be visually detected by naked eyes, which allows one to qualitatively evaluate the CEA level. Moreover, we confirm the reliability of using the amplified luminescence of Eu2O3 nanoprobes for direct quantitation of CEA in patient saliva samples, thus validates the practicality of the proposed strategy for both clinical diagnosis and home self-monitoring of tumor marker in human saliva.

CA724 predicts overall survival in locally advanced gastric cancer patients with neoadjuvant chemotherapy

Background

Serum tumor markers including AFU, AFP, CEA, CA199, CA125 and CA724, are of great importance in the diagnosis, prognostic prediction and recurrence monitoring of gastrointestinal malignancies. However, their significance in gastric cancer (GC) patients with neoadjuvant therapy (NCT) is still uncertain. The aim of this study was to evaluate the predictive value of these six tumor markers in locally advanced GC patients who underwent NCT and curative surgery.

Methods

In total, 290 locally advanced GC patients who underwent NCT and D2 radical gastrectomy were retrospectively analyzed. Data on their tumor markers before (pre-) and after (post-) NCT and pathological characteristics were extracted from the database of our hospital. The optimal cutoff values of the six tumor markers were calculated by the ROC curve and Youden index. Their predictive significance was analyzed and survival curves for overall survival (OS) were obtained by the Kaplan-Meier method. Associations between categorical variables were explored by the chi-square test or Fisher’s exact test. Multivariate analyses were performed by the Cox regression model.

Results

Pre- and post-CA199, −CA125 and -CA724 could predict overall survival (all P < 0.05), but only the change (diff-) of CA199 was related to prognosis (P = 0.05). In the multivariable analysis, pre- (P = 0.014) and post-CA724 (P = 0.036) remained significant, though diff-CA724 was not an independent prognostic factor (P = 0.581). In addition, pre- and post-CA199, −CA125 and -CA724 were associated with lymph node metastasis (N- vs N+) and pathological stage (I-II vs III) (all P < 0.05). Moreover, post-CA724 was related to the vascular or lymphatic invasion (P = 0.019), while pre-CA724 was not (P = 0.082). However, AFU, AFP and CEA showed no association with survival (P > 0.05).

Conclusions

CA724 is an independent factor for prognosis and could be used to predict ypN and ypTNM stage in locally advanced GC patients undergoing NCT and curative resection.

Dual-label time-resolved fluoroimmunoassay for simultaneous measurement of human epidermal growth factor receptor 2 and human epididymis protein 4 in serum

In this study, a novel dual-label time-resolved fluoroimmunoassay (TRFIA) is described for simultaneous quantification of human epidermal growth factor receptor 2 (HER-2) and human epididymis protein 4 (HE4) in serum to screen gynecologic cancers. A double-antibody sandwich TRFIA was introduced with europium and samarium chelates to simultaneously detect the concentrations of HER-2 and HE4. Under optimal conditions, the proposed method exhibited wide linear ranges for HER-2 of 0.07–500 ng ml−1 and for HE4 of 0.32–1000 pmol l−1 with the average coefficient of variation below 10%. The specificity was satisfied through determining the other common tumor markers. The recovery rates were 94.5% and 96.6% on average for HER-2 and HE4, respectively. Good correlations were observed in clinical samples between developed method and commercial chemiluminescence immunoassay kits. The results demonstrated that dual-label TRFIA for HER-2 and HE4 was rapid and precise, and therefore could have a promising use in large sample detection for gynecological cancer screening.

Comparison of Bead-Based Fluorescence Versus Planar Electrochemiluminescence Multiplex Immunoassays for Measuring Cytokines in Human Plasma

This study compared two 96-well multiplex immunoassay platforms for analytical performance in assessing cytokine concentrations in standards, quality controls and human plasma samples (n = 62), and evaluated assay time requirements. Assays included a bead-based fluorescence MILLIPLEX^® assay/Luminex fluorescence platform (LMX) and three kits from Meso Scale Discovery (MSD) in planar electrochemiluminescence format. The LMX kit evaluated 21 cytokines and the MSD kits evaluated 10 cytokines each, with 16 overlapping cytokines between platforms. Both assays provided good reproducibility in standard curves for all analytes. Interassay CVs of shared analytes showed average kit quality control CVs ranging 1.9–18.2% for LMX and 2.4–13.9% for MSD. The MSD platform had lower LLoQs than LMX for 14/16 shared cytokines. For IL-17, the LLoQ was lower with LMX than MSD, and the LLoQs for IL-6 were similar. Although MSD calibration curves indicated lower LLoQs for most of those analytes, many more cytokines in human plasma samples were not detected by MSD than by LMX. The ULoQs were higher in LMX versus MSD assays for 13/16 shared analytes, lower than MSD for IL-17, and equivalent between assays for IL-6 and MIP-1α. Bland-Altman plots indicated that MSD classified 13/16 shared analytes as concentrations lower than by LMX. Time and motion analysis indicated that total mean assay times were 20 h 28 m and 21 h 33 m for LMX and MSD, respectively, including an overnight (17 h) incubation. The MSD assays employed a manufacturer-approved overnight incubation instead of the standard 2-h incubation, which kit instructions suggest might increase detection sensitivity. Hands-on labor time averaged 1 h 37 m for LMX and 2 h 33 m for MSD. In summary, assay selection factors should include selection of specific markers of interest, time and cost considerations, and anticipated cytokine concentrations in prospective samples.

Salt-induced gold nanoparticles aggregation lights up fluorescence of DNA-silver nanoclusters to monitor dual cancer markers carcinoembryonic antigen and carbohydrate antigen 125

In clinical diagnosis of cancer, the monitoring of single tumor marker may result in many false and missed results, while simultaneous detection of multiple tumor markers should be more accuracy and effective. Here, we report a new strategy that salt-induced gold nanoparticles (AuNPs) aggregation lights up fluorescence of dual-color DNA-silver nanoclusters-aptamer (DNA-AgNCs-apta) for the simultaneous monitoring of carcinoembryonic antigen (CEA) and carbohydrate antigen 125 (CA125). The dual-color aptasensor system is composed of green-emitting DNA-AgNCs with CEA aptamer (gDNA₁-AgNCs-apta₁) and red-emitting DNA-AgNCs with CA125 aptamer (rDNA₂-AgNCs-apta₂) in the ratio of 1:1 in volume. Upon addition of AuNPs, gDNA₁-AgNCs-apta₁ and/or rDNA₂-AgNCs-apta₂ are flexibly adsorbed onto the surface of AuNPs by terminal aptamer(s), which prevents salt-induced AuNPs aggregation under high salt condition and results in fluorescence quenching based on surface plasmon enhanced energy transfer (SPEET). With the addition of CEA and/or CA125, the target(s) and corresponding aptamer(s) coordinate to form the complex, keeping DNA-AgNCs-apta(s) far away from the surface of AuNPs and making AuNPs aggregated in high salt medium. The AuNPs aggregation leads to the recovery of fluorescence signals of DNA-AgNCs-apta(s) due to weakened SPEET. Utilizing the fluorescence aptasensor system, the limit of detection of CEA and CA125 are as low as 7.5 pg·mL^-1 and 0.015 U·mL^-1, respectively. The proposed method can be applied to the selective and simultaneous determination of CEA and CA125 in human serum.

Soluble Tim3 detection by time-resolved fluorescence immunoassay and its application in membranous nephropathy

Background

We aimed to develop a time‐resolved fluorescence immunoassay (TRFIA) for detecting soluble T‐cell immunoglobulin and mucin domain 3 (sTim3) in serum samples and to demonstrate a preliminary application of this method in membranous nephropathy (MN).

Methods

sTim3 TRFIA was developed, and the sTim3 concentration in the serum of patients with MN and healthy individuals was detected using a sandwich method.

Results

The sensitivity of the developed sTim3 TRFIA was 0.66 ng/mL, higher than that of an enzyme‐linked immunosorbent assay (ELISA) (1.11 ng/mL). The detection range was 0.66‐40 ng/mL. The intra‐assay coefficient of variation (CV) for sTim3 was 1.64%‐4.68%, and the inter‐assay CV was 5.72%‐9.32%. The cross‐reactivity to interleukin 6 (IL‐6) and kidney injury molecule 1 (KIM‐1) was 0.25% and 0.04%, respectively. The average recovery was 105.26%. The sTim3 concentration in patients with MN was considerably higher than that in healthy individuals (P < .001). The sTim3 concentration in the serum of patients with MN was significantly increased from G1 to G4 based on the Jonckheere‐Terpstra test (P < .001). Thus, we used sTim3 as a diagnostic indicator for distinguishing between healthy individuals and patients with MN as well as between different stages of MN.

Conclusion

We successfully established TRFIA to detect sTim3 in serum. We then applied this method to patients with MN, demonstrating for the first time that TRFIA is a valid diagnostic tool to detect sTim3 in serum.