Paper microfluidic device for early diagnosis and prognosis of acute myocardial infarction via quantitative multiplex cardiac biomarker detection

Silica nanoparticles induce JNK-mediated inflammation and myocardial contractile dysfunction

Increasing environmental exposure to silica nanoparticles (SiNPs) and limited cardiotoxicity studies posed a challenge for the safety evaluation and management of these materials. This study aimed to explore the adverse effects and underlying mechanisms of subacute exposure to SiNPs on cardiac function in rats. Results from echocardiographic, ultrastructural and histopathological analysis found that SiNPs induced cardiac contractile dysfunction, accompanied by incomplete myocardial structures, disordered sarcomere segments, interstitial edema and myocyte apoptosis in heart. Levels of myocardial enzymes and inflammatory factors were markedly increased in both serum and heart tissue, accompanied by elevated levels of oxidative damage occurred in the hearts of SiNPs-treated rats. SiNPs significantly upregulated the expressions of inflammation and contraction-related proteins, including JNK, p-JNK, c-Jun, TF and PAR1. Lentivirus transfection of JNK shRNA showed the low-expression of JNK-facilitated F-actin and inhibited TF in the SiNPs-treated cardiomyocytes. Moreover, SiNPs activated the mRNA and protein levels of JNK/TF/PAR1 pathway, and these effects were significantly dampened after JNK knock down. Our results demonstrate that SiNPs trigger myocardial contractile dysfunction via JNK/TF/PAR1 signaling pathway.

SERS-based immunoassay using gold-patterned array chips for rapid and sensitive detection of dual cardiac biomarkers

Cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) are important diagnostic biomarkers for acute myocardial infarction (AMI). Many efforts have been undertaken to develop highly sensitive detection methods for the quantitative analysis of these dual targets. However, current immunoassay methods are inadequate for accurate measurement of cTnI and CK-MB, due to their limited detection sensitivity. Thus, there is still an urgent demand for a new technique that will enable ultrahigh sensitive detection of these biomarkers. In this study, we developed a surface-enhanced Raman scattering (SERS)-based sandwich immunoassay platform for the ultrasensitive detection of cTnI and CK-MB. In this study, a monoclonal-antibody-immobilized gold-patterned chip was used as a SERS active template. Target samples and polyclonal-antibody-conjugated Au@Ag core-shell nanoparticles were then added. Using this SERS platform, the concentration of biomarkers could be quantified by monitoring the characteristic Raman peak intensity of Raman reporter molecules. Under optimized conditions, the limits of detection (LODs) were estimated to be 8.9 pg mL-1 and 9.7 pg mL-1 for cTnI and CK-MB, respectively. Thus, the proposed SERS-based immunoassay has great potential to be an effective diagnostic tool for the rapid and accurate detection of cTnI and CK-MB.

Applications of paper as a support material in biomedical sciences: A decadal review

In human history, the paper has long been used as a platform to record and preserve information. However, over the decades, paper has found its application in Biomedical Sciences, too. Both paper-based microfluidic devices (μPADs) and paper-based cultures and scaffolds have shown immense potential to be used as a sensor as well as a supporting material for in vitro tissue engineering. μPADs can be used to perform low-cost and fast biomolecular assays at Point-Of-Care (POC). They are being used to detect various biomarkers like viral proteins, metabolites, oncogenes, and antigens; and conditions like Venous Thromboembolism (VTE). On the other hand, the paper has also been used to develop paper-based 3D cultures and scaffolds to test drugs, and monitor cytotoxic effects in vitro cell microenvironments and also as implantable tissues. In this review, we intend to enumerate the development in the field of μPADs, paper-based cell cultures, and paper-based scaffolds and their plethora of applications over the last decade.

Potential molecular mechanism of ACE gene at different time points in STEMI patients based on genome-wide microarray dataset

Background

This study aimed to investigate the angiotensin converting enzyme (ACE) co-expression genes and their pathways involved in ST-segment elevation myocardial infarction (STEMI) at different time points.

Methods

The array data set of GSE59867 was examined for the ACE co-expression genes in peripheral blood samples from 111 patients with STEMI at four time points (admission, discharge, and 1 and 6 months after MI). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, Gene Ontology (GO) annotation and protein-protein interaction (PPI) of the co-expression genes were determined using online analytical tools. The Cytoscape software was used to create modules and hub genes.

Results

The number of biological processes (BP), cellular components (CC) and molecular functions (MF) was 43, 22 and 24 at admission; 18, 19 and 11 at discharge; 30, 37 and 21 at 1 month after MI; and 12, 19 and 14 at 6 months after MI; respectively. There were 6 BP, 8 CC and 4 MF enriched at every time point. The co-expression genes were substantially enriched in 12, 5, 6 and 14 KEGG pathways at the four time points, respectively, but no KEGG pathway was found to be common in all time points. We identified 132 intersectional co-expression genes (90 positive and 42 negative) from the four time points and 17 BP, 13 CC, 11 MF and 7 KEGG pathways were enriched. In addition, the PPI network contained 129 nodes and 570 edges, and only 1 module was identified to be significantly enriched in just 1 BP (chromatin-mediated maintenance of transcription).

Conclusions

The results of the present study showed that the ACE co-expression genes and their pathways involved in STEMI were significantly different at four different time points. These findings may be helpful for further understanding the functions and roles of ACE in different stages of STEMI, and providing reference for the treatment of STEMI.

Using SERS-based microfluidic paper-based device (μPAD) for calibration-free quantitative measurement of AMI cardiac biomarkers

Recently, surface enhanced Raman scattering (SERS) has attracted much attention in medical diagnosis applications owing to better detection sensitivity and lower limit of detection (LOD) than colorimetric detection. In this paper, a novel calibration-free SERS-based μPAD with multi-reaction zones for simultaneous quantitative detection of multiple cardiac biomarkers - GPBB, CK-MB and cTnT for early diagnosis and prognosis of acute myocardial infarction (AMI) are presented. Three distinct Raman probes were synthesised, subsequently conjugated with respective detecting antibodies and used as SERS nanotags for cardiac biomarker detection. Using a conventional calibration curve, quantitative simultaneous measurement of multiple cardiac biomarkers on SERS-based μPAD was performed based on the characteristic Raman spectral features of each reporter used in different nanotags. However, a calibration free point-of-care testing device is required for fast screening to rule-in and rule-out AMI patients. Partial least squares predictive models were developed and incorporated into the immunosensing system, to accurately quantify the three unknown cardiac biomarkers levels in serum based on the previously obtained Raman spectral data. This method allows absolute quantitative measurement when conventional calibration curve fails to provide accurate estimation of cardiac biomarkers, especially at low and high concentration ranges. Under an optimised condition, the LOD of our SERS-based μPAD was identified at 8, 10, and 1 pg mL^-1, for GPBB, CK-MB and cTnT, respectively, which is well below the clinical cutoff values. Therefore, this proof-of-concept technique shows significant potential for highly sensitive quantitative detection of multiplex cardiac biomarkers in human serum to expedite medical decisions for enhanced patient care.

Spatiotemporally Controlled Multiplexed Photothermal Microfluidic Pumping under Monitoring of On-Chip Thermal Imaging

Intelligent contactless microfluidic pumping strategies have been increasingly desirable for operation of lab-on-a-chip devices. Herein, we present a photothermal microfluidic pumping strategy for on-chip multiplexed cargo transport in a contactless and spatiotemporally controllable fashion based on the application of near-infrared laser-driven photothermal effect in microfluidic paper-based devices (μPDs). Graphene oxide (GO)-doped thermoresponsive poly(N-isopropylacrylamide)-acrylamide hydrogels served as the photothermally responsive cargo reservoirs on the μPDs. In response to remote contactless irradiation by an 808 nm laser, on-chip phase transition of the composite hydrogels was actuated in a switchlike manner as a result of the photothermal effect of GO, enabling robust on-chip pumping of cargoes from the hydrogels to predefined arrays of reaction zones. The thermal imaging technique was employed to monitor the on-chip photothermal pumping process. The microfluidic pumping performance can be spatiotemporally controlled in a quantitative way by remotely tuning the laser power, irradiation time, and GO concentration. The pumping strategy was exemplified by FeCl₃ and horseradish peroxidase as the model cargoes to implement on-chip Prussian blue- and 3,3',5,5'-tetramethylbenzidine-based colorimetric reactions, respectively. Furthermore, multiplexed on-demand microfluidic pumping was achieved by flexibly adjusting the irradiation pathway and the microfluidic pattern. The new microfluidic pumping strategy shows great promise for diverse microfluidic applications due to its flexibility, high integratability into lab-on-a-chip devices, and contactless and spatiotemporal controllability.