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1.
Small ; : e2311071, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38639331

ABSTRACT

Prostate cancer (PCa) has become a public health concern in elderly men due to an ever-increasing number of estimated cases. Unfortunately, the available treatments are unsatisfactory because of a lack of a durable response, especially in advanced disease states. Extracellular vesicles (EVs) are lipid-bilayer encircled nanoscale vesicles that carry numerous biomolecules (e.g., nucleic acids, proteins, and lipids), mediating the transfer of information. The past decade has witnessed a wide range of EV applications in both diagnostics and therapeutics. First, EV-based non-invasive liquid biopsies provide biomarkers in various clinical scenarios to guide treatment; EVs can facilitate the grading and staging of patients for appropriate treatment selection. Second, EVs play a pivotal role in pathophysiological processes via intercellular communication. Targeting key molecules involved in EV-mediated tumor progression (e.g., proliferation, angiogenesis, metastasis, immune escape, and drug resistance) is a potential approach for curbing PCa. Third, EVs are promising drug carriers. Naïve EVs from various sources and engineered EV-based drug delivery systems have paved the way for the development of new treatment modalities. This review discusses the recent advancements in the application of EV therapies and highlights EV-based functional materials as novel interventions for PCa.

2.
Article in English | MEDLINE | ID: mdl-38017017

ABSTRACT

Extracellular vesicles (EVs) are emerging as crucial materials for precision theragnostic applications. However, current separation methods are time-consuming, costly, and not scalable and deliver limited yields or purity. Here, we present EV precipitation by ionic strength modulation (ExoPRISM), a simple, low-cost, user-friendly, and readily adaptable approach for separating EVs in high yields without compromising their biological functions. Adding an electrolyte solution to blood plasma in small increments generates the sequential precipitation of proteins and EVs, allowing for fractional separation of EVs using low-speed centrifugation. The coprecipitated electrolytes are easily washed away, and the entire EV separation and washing process takes less than an hour. This approach successfully separates EVs from a broad range of volumes and types of biological fluids, including culture medium, urine, plasma, and serum, showing promise as a robust tool for next-generation liquid biopsies and regenerative medicine.

3.
Lab Chip ; 22(14): 2726-2740, 2022 07 12.
Article in English | MEDLINE | ID: mdl-35763032

ABSTRACT

In preclinical and clinical studies, it has been demonstrated that tumor-educated platelets play a critical role in tumorigenesis, cancer development, and metastasis. Unlike the role of cancer-derived chemokines in platelet activation, the role of cancer-derived extracellular vesicles (EVs) has remained elusive. Here, we found that interleukin-8 (IL-8) in cancer-derived EVs contributed to platelet activation by increasing P-selectin expression and ligand affinity, resulting in increased platelet adhesion on the human vessel-mimicking microfluidic system. Furthermore, platelet adhesion levels on vessels treated with human plasma-derived EVs demonstrated good discrimination between breast cancer patients with metastasis and those without, with the area under the curve (AUC) value of 0.88. While EpCAM expression on EVs could detect the existence of a tumor (AUC = 0.89), it performed poorly in predicting metastasis (AUC = 0.42). We believe that these findings shed light on the role of the interaction between cancer-derived EVs and platelets in pre-metastatic niche formation and tumor metastasis, potentially leading to the development of platelet-tumor interaction-based novel diagnostic and therapeutic strategies.


Subject(s)
Breast Neoplasms , Extracellular Vesicles , Blood Platelets/metabolism , Breast Neoplasms/pathology , Extracellular Vesicles/metabolism , Female , Humans , Neoplasm Metastasis/pathology , Platelet Activation , Platelet Adhesiveness
4.
Lab Chip ; 22(2): 377-386, 2022 01 18.
Article in English | MEDLINE | ID: mdl-34927189

ABSTRACT

Dendritic cells (DCs), which are immune sentinels in the peripheral tissues, play a number of roles, including patrolling for pathogens, internalising antigens, transporting antigens to the lymph nodes (LNs), interacting with T cells, and secreting cytokines. The well-coordinated migration of DCs under various immunological or inflammatory conditions is therefore essential to ensure an effective immune response. Upon maturation, DCs migrate faster and more persistently than immature DCs (iDCs), which is believed to facilitate CCR7-dependent chemotaxis. It has been reported that lipopolysaccharide-activated DCs produce IL-12 only transiently, and become resistant to further stimulation through exhaustion. However, little is known about the influence of DC exhaustion on cellular motility. Here, we studied the cellular migration of exhausted DCs in tissue-mimicked confined environments. We found that the speed of exhausted matured DCs (xmDCs) decreased significantly compared to active matured DCs (amDCs) and iDCs. In contrast, the speed fluctuation increased compared to that of amDCs and was similar to that of iDCs. In addition, the diffusivity of the xmDCs was significantly lower than that of the amDCs, which implies that DC exhaustion reduces the space exploration ability. Interestingly, CCR7-dependent chemotaxis against CCL19 in xmDCs was not considerably different from that observed in amDCs. Taken together, we report a unique intrinsic cell migration behaviour of xmDCs, which exhibit a slower, less persistent, and less diffusive random motility, which results in the DCs remaining at the site of infection, although a well-preserved CCR7-dependent chemotactic motility is maintained.


Subject(s)
Chemotaxis , Dendritic Cells , Cell Movement , Cytokines , Receptors, CCR7
5.
Acc Chem Res ; 54(19): 3643-3655, 2021 10 05.
Article in English | MEDLINE | ID: mdl-34516092

ABSTRACT

Reliable, inexpensive, and rapid diagnostic tools are essential to control and prevent the spread of infectious diseases. Many commercial kits for coronavirus disease 2019 (COVID-19) diagnostics have played a crucial role in the fight against the COVID-19 pandemic. Most current standard in vitro diagnostic (IVD) protocols for infectious diseases are sensitive but time-consuming and require sophisticated laboratory equipment and specially trained personnel. Recent advances in biosensor technology suggest the potential to deliver point-of-care (POC) diagnostics that are affordable and provide accurate results in a short time. The ideal "sample-in-answer-out" type fully integrated POC infection diagnostic platforms are expected to be autonomous or easy-to-operate, equipment-free or infrastructure-independent, and high-throughput or easy to upscale. In this Account, we detail the recent progress made by our group and others in the development of centrifugal microfluidic devices or lab-on-a-disc (LOAD) systems. Unlike conventional pump-based fluid actuation, the centrifugal force generated by spinning the disc induces liquid pumping and no external fluidic interconnects are required. This allows a total fluidic network required for multiple steps of biological assays to be integrated on a disc, enabling fully automated POC diagnostics. Various applications have been demonstrated, including liquid biopsy for personalized cancer management, food applications, and environmental monitoring; here, we focus on IVD for infectious disease. First, we introduce various on-disc unit operation technologies, including reagent storage, sedimentation, filtration, valving, decanting, aliquoting, mixing, separation, serial dilution, washing, and calibration. Such centrifugal microfluidic technologies have already proved promising for micro-total-analysis systems for automated IVD ranging from molecular detection of pathogens to multiplexed enzyme-linked immunosorbent assays (ELISAs) that use raw samples such as whole blood or saliva. Some recent examples of LOAD systems for molecular diagnostics in which some or all steps of the assays are integrated on a disc, including pathogen enrichment, nucleic acid extraction, amplification, and detection, are discussed in detail. We then introduce fully automated ELISA systems with enhanced sensitivity. Furthermore, we demonstrate a toy-inspired fidget spinner that enables electricity-free and rapid analysis of pathogens from undiluted urine samples of patients with urinary tract infection symptoms and a phenotypic antimicrobial susceptibility test for an extreme POC diagnostics application. Considering the urgent need for cost-effective and reliable POC infection diagnostic tools, especially in the current pandemic crisis, the current limitations and future directions of fast and broad adaptation in real-world settings are also discussed. With proper attention to key challenges and leverage with recent advances in bio-sensing technologies, molecular biology, nanomaterials, analytical chemistry, miniaturization, system integration, and data management, LOAD systems hold the potential to deliver POC infection diagnostic tools with unprecedented performance regarding time, accuracy, and cost. We hope the new insight and promise of LOAD systems for POC infection diagnostics presented in this Account can spark new ideas and inspire further research and development to create better healthcare systems for current and future pandemics.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Point-of-Care Systems , Biosensing Techniques/methods , COVID-19/virology , COVID-19 Testing/instrumentation , Centrifugation , Humans , Lab-On-A-Chip Devices , RNA, Viral/analysis , RNA, Viral/isolation & purification , RNA, Viral/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification
6.
ACS Nano ; 14(11): 14971-14988, 2020 11 24.
Article in English | MEDLINE | ID: mdl-32880442

ABSTRACT

The liver is one of the most common sites of breast cancer metastasis and is associated with high lethality. Although the interaction between tumor cells and their microenvironment at metastatic sites has been recognized as a key regulator of tumor progression, the underlying mechanism is not fully elucidated. Here, we describe a three-dimensional (3D) microfluidic human liver-on-a-chip (liver-chip) that emulates the formation of a premetastatic niche to investigate the roles of breast cancer-derived extracellular vesicles (EVs) in liver metastasis. We demonstrate that breast cancer-derived EVs activate liver sinusoidal endothelial cells (LSECs) in the liver-chip, inducing endothelial to mesenchymal transition and destruction of vessel barriers. In addition, we show that transforming growth factor ß1 (TGFß1) in breast cancer-derived EVs upregulates fibronectin, an adhesive extracellular matrix protein, on LSECs, which facilitates the adhesion of breast cancer cells to the liver microenvironment. Furthermore, we observed that EVs isolated from triple-negative breast cancer (TNBC) patients with liver metastasis contain higher TGFß1 levels and induce adhesion of more breast cancer cells to the 3D human liver-chip than do EVs isolated from healthy donors or nonmetastatic TNBC patients. These findings provide a better understanding of the mechanisms through which breast cancer-derived EVs guide secondary metastasis to the liver. Furthermore, the 3D human liver-chip described in this study provides a platform to investigate the mechanisms underlying secondary metastasis to the liver and possible therapeutic strategies.


Subject(s)
Extracellular Vesicles , Liver , Triple Negative Breast Neoplasms , Endothelial Cells , Humans , Lab-On-A-Chip Devices , Liver/physiology , Oligonucleotide Array Sequence Analysis , Tumor Microenvironment
7.
Anal Chem ; 92(8): 6010-6018, 2020 04 21.
Article in English | MEDLINE | ID: mdl-32207920

ABSTRACT

Tumor-derived extracellular vesicles (EVs) have emerged as a promising source of circulating biomarkers for liquid biopsies. However, understanding the heterogeneous physical and biochemical properties of EVs originating from multiple complex biogenesis pathways remains a major challenge. Here, we introduce EV-Ident for preparation of subpopulations of EVs in three different size fractions: large EVs (EV200 nm; 200-1 000 nm), medium EVs (EV100 nm; 100-200 nm), and small EVs (EV20 nm; 20-100 nm). Furthermore, this technology enables the in situ labeling of fluorescence markers for the protein profiling of individual EVs. As a proof-of-concept, we analyzed the presence of human epidermal growth factor receptor 2 (HER2) and prostate-specific membrane antigen (PSMA) in breast cancer and prostate cancer cell-derived EVs, respectively, using three different size fractions at the single-EV level. By reducing the complexity of EV heterogeneity in each size fraction, we found that HER2-positive breast cancer cells showed the greatest expression of HER2 in EV20 nm, whereas PSMA expression was the highest in EV200 nm derived from PSMA-expressing prostate cancer cells. This increase in HER2 expression in EV20 nm and PSMA expression in EV200 nm was further confirmed in plasma-derived nanoparticles (PNPs) obtained from breast and prostate cancer patients, respectively. Our study demonstrates that single-EV analysis using EV-Ident provides a practical way to understand EV heterogeneity and to successfully identify potent subpopulation of EVs for breast and prostate cancer, which has promising translational implications for cancer theranostics. Furthermore, these findings have the potential to address fundamental questions surrounding the biology and clinical applications of EVs.


Subject(s)
Antigens, Surface/blood , Biomarkers, Tumor/blood , Breast Neoplasms/blood , Extracellular Vesicles/chemistry , Glutamate Carboxypeptidase II/blood , Prostatic Neoplasms/blood , Receptor, ErbB-2/blood , Breast Neoplasms/diagnosis , Female , Humans , Male , Particle Size , Prostatic Neoplasms/diagnosis , Surface Properties
8.
Lab Chip ; 20(5): 949-957, 2020 03 03.
Article in English | MEDLINE | ID: mdl-31989123

ABSTRACT

Platelets play crucial roles in hemostasis and immunity. Over the last decades, clinical evidence has revealed the significance of platelets as complementary biomarkers for the detection and treatment of various diseases, including cancer. Due to a lack of well standardized convenient isolation methods for platelets, pre-analytical factors such as complex handling procedures negatively impact the quality of the platelet samples, including overactivation, low purity, and poor reproducibility. This may lead to biased interpretation of various downstream analyses, such as proteomic and genomic analyses. Herein, we describe a fully automated lab-on-a-disc-based method of platelet isolation from a small volume of blood (<1 mL). This method provides higher yields (>4 folds) and purity (>99%) and lower platelet activation than the conventional method. Moreover, it was also superior in the detection of platelet-related RNAs CD41, PF4, and P2Y12 due to lower contamination with white blood cells.


Subject(s)
Blood Platelets , Lab-On-A-Chip Devices , Pathology, Molecular , Proteomics , Reproducibility of Results
9.
Soft Matter ; 15(30): 6127-6133, 2019 Aug 14.
Article in English | MEDLINE | ID: mdl-31290906

ABSTRACT

We investigate the effects of poly(ethylene glycol) (PEG) doping on nematic lyotropic chromonic liquid crystals (LCLCs) confined in a cylindrical cavity. First, PEG added to Sunset Yellow (SSY) renders confining glass surfaces nemato-phobic by adsorption. We also confirm that the grafting of PEG to bare glass surfaces changes them from nemato-philic to nemato-phobic. This change in the wetting behavior affects how nematic director configurations form and relax. Additionally, we observe that PEG-doped nematic SSY retains the double-twist director configuration as in the PEG-free case. However, the PEG-doped nematic SSY is accompanied by unprecedented domain-wall-like defects and heterogeneity in the director configuration. We propose multiple hypotheses on how PEG changes the director configuration, including the formation of meta-stable director configurations.

10.
Theranostics ; 9(7): 1851-1863, 2019.
Article in English | MEDLINE | ID: mdl-31037143

ABSTRACT

Extracellular vesicles (EVs) that circulate in body fluids possess significant potential for disease diagnosis. Their use in clinical settings, however, has been limited owing to lack of simple and robust isolation methods. To rectify this problem, a centrifugal device for automatic, fast, and efficient isolation of EVs from whole-blood, called Exodisc-B is presented in this paper. Methods: The device comprises a built-in chamber to facilitate plasma separation and two nanoporous filters-one for removing larger particles and the other for enriching EVs. The performance of the device in comparison to ultracentrifugation (UC) was evaluated by analyzing the yield, purity, protein and RNA content of the isolated EVs. Additionally, the EV protein marker expressions were measured by ELISA and statistically analyzed to differentiate prostate cancer patients from healthy donors. Results: Compared with the UC technique, the proposed device is capable of isolating at least an order of magnitude higher number of EVs with about 30-fold higher mRNA count within 40 min. Sandwich ELISA of EV-specific membrane proteins-CD9-CD81-confirmed that Exodisc-B can isolate EVs from a volume of whole blood as low as 30 µL with a capture efficiency exceeding 75%. The device also facilitates temporal monitoring of tumor progression within live mouse xenograft models over a period of 13 weeks while using minimal volumes of weekly collected blood samples. Further, in ELISA analyses of multiple cancer-related proteins, such as prostate-specific antigen (PSA), prostate-specific membrane antigen (PSMA), epithelial cell adhesion molecule (EpCAM), epidermal growth factor receptor 1 (EGFR1), and heat shock protein 90 (HSP90), extracted from EVs isolated from human plasma, 43 patients were differentiated from 30 healthy donors. Conclusion: The results demonstrated the ability of Exodisc-B to provide a rapid, sensitive, and point-of-care-type method for extracting intact EVs from small volumes of clinical blood samples for disease diagnosis and monitoring.


Subject(s)
Automation, Laboratory/methods , Extracellular Vesicles/physiology , Prostatic Neoplasms/diagnosis , Animals , Biomarkers, Tumor/metabolism , Blood Donors , Enzyme-Linked Immunosorbent Assay/methods , Extracellular Vesicles/metabolism , Humans , Male , Mice , Mice, Nude , Prostatic Neoplasms/metabolism , RNA, Messenger/metabolism , Ultracentrifugation/methods
11.
Lab Chip ; 19(1): 87-97, 2018 12 18.
Article in English | MEDLINE | ID: mdl-30500003

ABSTRACT

Androgen-receptor splice variant 7 (AR-V7) is associated with castration-resistant prostate cancer (CRPC) and resistance to anti-androgen therapy. Despite its clinical importance, the lack of efficient methods for AR-V7 analysis remains a challenge for broader use of this biomarker in routine clinical practice. Herein, we suggest a practical and non-invasive liquid biopsy method for analysis of AR-V7 in the RNA of urine-derived extracellular vesicles (EVs) without the need for blood withdrawal. Urine-derived EVs were isolated by a lab-on-a-disc integrated with six independent nanofiltration units (Exo-Hexa) allowing simultaneous processing of six individual samples. Rapid enrichment of EVs (<30 min) from each 4 mL urine sample was followed by mRNA extraction, and AR-V7 and androgen receptor full-length (AR-FL) mRNA levels in the urinary EVs were quantified by droplet digital polymerase chain reaction (ddPCR) as absolute concentrations (copies per mL). Higher AR-V7 and lower AR-FL expressions were detected in urine-derived EVs from 14 patients with CRPC than in those from 22 patients with hormone-sensitive prostate cancer. Additionally, we found that AR-V7 transcript levels and the AR-V7/AR-FL ratio in urinary EVs were higher in patients with advanced prostate cancer. This study is the first to report that RNA of urine-derived EVs is a reliable source for AR-V7 expression analysis. The proposed method for quantifying AR-V7 in urinary EVs prepared by a lab-on-a-disc is therefore a simple and promising approach to liquid biopsy with great potential for therapeutic impact on prostate cancer.


Subject(s)
Extracellular Vesicles , Liquid Biopsy/methods , Prostatic Neoplasms, Castration-Resistant/urine , Receptors, Androgen/analysis , Humans , Limit of Detection , Linear Models , Male , Polymerase Chain Reaction , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Messenger/urine , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Reproducibility of Results
12.
Micromachines (Basel) ; 9(3)2018 Feb 28.
Article in English | MEDLINE | ID: mdl-30424034

ABSTRACT

Lung cancer is by far the leading cause of cancer death worldwide, with non-small cell lung cancer (NSCLC) accounting for the majority of cases. Recent advances in the understanding of the biology of tumors and in highly sensitive detection technologies for molecular analysis offer targeted therapies, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. However, our understanding of an individual patient's lung cancer is often limited by tumor accessibility because of the high risk and invasive nature of current tissue biopsy procedures. "Liquid biopsy", the analysis of circulating biomarkers from peripheral blood, such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), offers a new source of cancer-derived materials that may reflect the status of the disease better and thereby contribute to more personalized treatment. In this review, we examined the clinical significance and uniqueness of CTCs and ctDNA from NSCLC patients, isolation and detection methods developed to analyze each type of circulating biomarker, and examples of clinical studies of potential applications for early diagnosis, prognosis, treatment monitoring, and prediction of resistance to therapy. We also discuss challenges that remain to be addressed before such tools are implemented for routine use in clinical settings.

13.
Lab Chip ; 18(9): 1320-1329, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29658031

ABSTRACT

The potential utility of circulating tumour DNA (ctDNA) in patient blood for cancer diagnostics and real-time monitoring of disease progression is highly recognized. However, the lack of automated and efficient methods for cell-free DNA (cfDNA) isolation from peripheral blood has remained a challenge for broader acceptance of liquid biopsy in general clinical settings. Here, we demonstrate a lab-on-a-disc system equipped with newly developed, electromagnetically actuated, and reversible diaphragm valves that allows fully automated and rapid (<30 min) isolation of cfDNA from whole blood (>3 ml) to achieve high detection sensitivity by minimizing the degradation of fragile ctDNA as well as contamination of wild-type DNA from abundant blood cells. As a proof of concept study, we used the lab-on-a-disc to isolate cfDNA from patients with non-small cell lung cancer and successfully detected epidermal growth factor receptor gene mutations (L858R, T790M) during targeted drug therapy. The proposed lab-on-a-disc enables a fully automated, rapid, and point-of-care cfDNA enrichment starting from whole blood to facilitate the wide use of liquid biopsy in routine clinical practice.


Subject(s)
Carcinoma, Non-Small-Cell Lung/blood , Circulating Tumor DNA/blood , Circulating Tumor DNA/isolation & purification , Lung Neoplasms/blood , Microfluidic Analytical Techniques/instrumentation , Automation, Laboratory/instrumentation , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/therapy , Disease Progression , Equipment Design , Humans , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Lung Neoplasms/therapy , Mutation , Real-Time Polymerase Chain Reaction/instrumentation
15.
ACS Nano ; 11(2): 1360-1370, 2017 02 28.
Article in English | MEDLINE | ID: mdl-28068467

ABSTRACT

Extracellular vesicles (EVs) are cell-derived, nanoscale vesicles that carry nucleic acids and proteins from their cells of origin and show great potential as biomarkers for many diseases, including cancer. Efficient isolation and detection methods are prerequisites for exploiting their use in clinical settings and understanding their physiological functions. Here, we presented a rapid, label-free, and highly sensitive method for EV isolation and quantification using a lab-on-a-disc integrated with two nanofilters (Exodisc). Starting from raw biological samples, such as cell-culture supernatant (CCS) or cancer-patient urine, fully automated enrichment of EVs in the size range of 20-600 nm was achieved within 30 min using a tabletop-sized centrifugal microfluidic system. Quantitative tests using nanoparticle-tracking analysis confirmed that the Exodisc enabled >95% recovery of EVs from CCS. Additionally, analysis of mRNA retrieved from EVs revealed that the Exodisc provided >100-fold higher concentration of mRNA as compared with the gold-standard ultracentrifugation method. Furthermore, on-disc enzyme-linked immunosorbent assay using urinary EVs isolated from bladder cancer patients showed high levels of CD9 and CD81 expression, suggesting that this method may be potentially useful in clinical settings to test urinary EV-based biomarkers for cancer diagnostics.


Subject(s)
Biomarkers, Tumor/analysis , Extracellular Vesicles/chemistry , Nanofibers/chemistry , RNA, Messenger/analysis , Urinary Bladder Neoplasms/urine , Computer-Aided Design , Enzyme-Linked Immunosorbent Assay , Gold/chemistry , Humans , Particle Size , Surface Properties , Tumor Cells, Cultured , Ultracentrifugation , Urinary Bladder Neoplasms/diagnosis
16.
Lab Chip ; 16(19): 3741-9, 2016 10 07.
Article in English | MEDLINE | ID: mdl-27534824

ABSTRACT

A lab-on-a-disc is a unique microfluidic platform that utilizes centrifugal force to pump liquids. This offers many benefits for point-of-care devices because it eliminates the need for connections to multiple pumps and complex tubing connections. A wide range of applications including clinical chemistry, immunoassay, cell analysis, and nucleic acid tests could be demonstrated on a spinning disc. To enable the performance of assays in a fully integrated and automated manner, the robust actuation of integrated valves is a prerequisite. However, conventional passive-type valves incur a critical drawback in that their operation is dependent on the rotational frequency, which is easily influenced by the channel geometry and chemistry, in addition to the physical properties of the liquids to be transferred. Even though a few active-type valving techniques permit the individual actuation of valves, independent of the rotational frequency, complex procedures for the fabrication as well as actuation mechanisms have prevented their broader acceptance in general applications. Here, we report on a lab-on-a-disc incorporating individually addressable diaphragm valves (ID valves) that enable the reversible and thermally stable actuation of multiple valves with unprecedented ease and robustness. These ID valves are configured from an elastic epoxy diaphragm embedded on a 3D printed push-and-twist valve, which can be easily actuated by a simple automatic driver unit. As a proof of concept experiment, an enzyme-linked immunosorbent assay (ELISA) and a polymerase chain reaction (PCR) were performed on a disc in a fully automated manner to demonstrate the robust, reversible, leak-free, and thermally stable actuation of the valves.


Subject(s)
Lab-On-A-Chip Devices , Membranes, Artificial , Temperature , Elastomers/chemistry , Enzyme-Linked Immunosorbent Assay , Epoxy Compounds/chemistry , Humans , Polymerase Chain Reaction , Prostate-Specific Antigen/blood , Staphylococcus aureus/genetics
17.
J Vis Exp ; (110)2016 04 16.
Article in English | MEDLINE | ID: mdl-27167836

ABSTRACT

Enzyme-linked immunosorbent assay (ELISA) is a promising method to detect small amount of proteins in biological samples. The devices providing a platform for reduced sample volume and assay time as well as full automation are required for potential use in point-of-care-diagnostics. Recently, we have demonstrated ultrasensitive detection of serum proteins, C-reactive protein (CRP) and cardiac troponin I (cTnI), utilizing a lab-on-a-disc composed of TiO2 nanofibrous (NF) mats. It showed a large dynamic range with femto molar (fM) detection sensitivity, from a small volume of whole blood in 30 min. The device consists of several components for blood separation, metering, mixing, and washing that are automated for improved sensitivity from low sample volumes. Here, in the video demonstration, we show the experimental protocols and know-how for the fabrication of NFs as well as the disc, their integration and the operation in the following order: processes for preparing TiO2 NF mat; transfer-printing of TiO2 NF mat onto the disc; surface modification for immune-reactions, disc assembly and operation; on-disc detection and representative results for immunoassay. Use of this device enables multiplexed analysis with minimal consumption of samples and reagents. Given the advantages, the device should find use in a wide variety of applications, and prove beneficial in facilitating the analysis of low abundant proteins.


Subject(s)
C-Reactive Protein/isolation & purification , Microfluidic Analytical Techniques/methods , Troponin I/isolation & purification , Biomarkers/blood , C-Reactive Protein/analysis , Enzyme-Linked Immunosorbent Assay/methods , Lab-On-A-Chip Devices , Microfluidic Analytical Techniques/instrumentation , Troponin I/blood
18.
Analyst ; 141(2): 371-81, 2016 Jan 21.
Article in English | MEDLINE | ID: mdl-26535415

ABSTRACT

Extracellular vesicles (EVs) are cell-derived nanovesicles, present in almost all types of body fluids, which play an important role in intercellular communication and are involved in the transport of biological signals for regulating diverse cellular functions. Due to the increasing clinical interest in the role of EVs in tumor promotion, various techniques for their isolation, detection, and characterization are being developed. In this review, we present an overview of the current EV isolation and characterization methods in addition to their applications and limitations. Furthermore, EVs as the potential emerging biomarkers in cancer management and their clinical implementation are briefly discussed.


Subject(s)
Cell Fractionation/methods , Extracellular Vesicles/pathology , Neoplasms/diagnosis , Neoplasms/pathology , Extracellular Vesicles/metabolism , Humans , Prognosis
19.
Micromachines (Basel) ; 7(2)2016 Feb 19.
Article in English | MEDLINE | ID: mdl-30407405

ABSTRACT

The advantages offered by centrifugal microfluidic systems have encouraged its rapid adaptation in the fields of in vitro diagnostics, clinical chemistry, immunoassays, and nucleic acid tests. Centrifugal microfluidic devices are currently used in both clinical and point-of-care settings. Recent studies have shown that this new diagnostic platform could be potentially used in extreme point-of-care settings like remote villages in the Indian subcontinent and in Africa. Several technological inventions have decentralized diagnostics in developing countries; however, very few microfluidic technologies have been successful in meeting the demand. By identifying the finest difference between the point-of-care testing and extreme point-of-care infrastructure, this review captures the evolving diagnostic needs of developing countries paired with infrastructural challenges with technological hurdles to healthcare delivery in extreme point-of-care settings. In particular, the requirements for making centrifugal diagnostic devices viable in developing countries are discussed based on a detailed analysis of the demands in different clinical settings including the distinctive needs of extreme point-of-care settings.

20.
Lab Chip ; 15(2): 478-85, 2015 Jan 21.
Article in English | MEDLINE | ID: mdl-25407164

ABSTRACT

ELISA-based devices are promising tools for the detection of low abundant proteins in biological samples. Reductions of the sample volume and assay time as well as full automation are required for their potential use in point-of-care diagnostic applications. Here, we present a highly efficient lab-on-a-disc composed of a TiO2 nanofibrous mat for sensitive detection of serum proteins with a broad dynamic range, with only 10 µL of whole blood within 30 min. The TiO2 nanofibers provide high specific surface area as well as active functional groups to capture large amounts of antibodies on the surface. In addition, the device offers efficient mixing and washing for improving the signal-to-noise ratio, thus enhancing the overall detection sensitivity. We employ the device for the detection of cardiac biomarkers, C-reactive protein (CRP) and cardiac troponin I (cTnI), spiked in phosphate-buffered saline (PBS) as well as in serum or whole blood. The device exhibited a wide dynamic range of six orders of magnitude from 1 pg mL(-1) (~8 fM) to 100 ng mL(-1) (~0.8 pM) and a low detection limit of 0.8 pg mL(-1) (~6 fM) for CRP spiked in CRP-free serum and a dynamic range of 10 pg mL(-1) (~0.4 pM) to 100 ng mL(-1) (~4 nM) with a detection limit of 37 pg mL(-1) (~1.5 pM) for cTnI spiked in whole blood.


Subject(s)
C-Reactive Protein/analysis , Enzyme-Linked Immunosorbent Assay/methods , Nanofibers/chemistry , Titanium/chemistry , Troponin I/blood , Biomarkers/blood , Enzyme-Linked Immunosorbent Assay/instrumentation , Heart Diseases/diagnosis , Humans , Lab-On-A-Chip Devices
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