953 research outputs found

    Microchips and their significance in isolation of circulating tumor cells and monitoring of cancers

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    In micro-fluid systems, fluids are injected into extremely narrow polymer channels in small amounts such as micro-, nano-, or pico-liter scales. These channels themselves are embedded on tiny chips. Various specialized structures in the chips including pumps, valves, and channels allow the chips to accept different types of fluids to be entered the channel and along with flowing through the channels, exert their effects in the framework of different reactions. The chips are generally crystal, silicon, or elastomer in texture. These highly organized structures are equipped with discharging channels through which products as well as wastes of the reactions are secreted out. A particular advantage regarding the use of fluids in micro-scales over macro-scales lies in the fact that these fluids are much better processed in the chips when they applied as micro-scales. When the laboratory is miniaturized as a microchip and solutions are injected on a micro-scale, this combination makes a specialized construction referred to as "lab-on-chip". Taken together, micro-fluids are among the novel technologies which further than declining the costs; enhancing the test repeatability, sensitivity, accuracy, and speed; are emerged as widespread technology in laboratory diagnosis. They can be utilized for monitoring a wide spectrum of biological disorders including different types of cancers. When these microchips are used for cancer monitoring, circulatory tumor cells play a fundamental role

    Microfluidics for studying metastatic patterns of lung cancer

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    The incidence of lung cancer continues to rise worldwide. Because the aggressive metastasis of lung cancer cells is the major drawback of successful therapies, the crucial challenge of modern nanomedicine is to develop diagnostic tools to map the molecular mechanisms of metastasis in lung cancer patients. In recent years, microfluidic platforms have been given much attention as tools for novel point-of-care diagnostic, an important aspect being the reconstruction of the body organs and tissues mimicking the in vivo conditions in one simple microdevice. Herein, we present the first comprehensive overview of the microfluidic systems used as innovative tools in the studies of lung cancer metastasis including single cancer cell analysis, endothelial transmigration, distant niches migration and finally neoangiogenesis. The application of the microfluidic systems to study the intercellular crosstalk between lung cancer cells and surrounding tumor microenvironment and the connection with multiple molecular signals coming from the external cellular matrix are discussed. We also focus on recent breakthrough technologies regarding lab-on-chip devices that serve as tools for detecting circulating lung cancer cells. The superiority of microfluidic systems over traditional in vitro cell-based assays with regard to modern nanosafety studies and new cancer drug design and discovery is also addressed. Finally, the current progress and future challenges regarding printable and paper-based microfluidic devices for personalized nanomedicine are summarized.publishedVersio

    Applications of molecular communications to medicine: A survey

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    In recent years, progresses in nanotechnology have established the foundations for implementing nanomachines capable of carrying out simple but significant tasks. Under this stimulus, researchers have been proposing various solutions for realizing nanoscale communications, considering both electromagnetic and biological communications. Their aim is to extend the capabilities of nanodevices, so as to enable the execution of more complex tasks by means of mutual coordination, achievable through communications. However, although most of these proposals show how devices can communicate at the nanoscales, they leave in the background specific applications of these new technologies. Thus, this paper shows an overview of the actual and potential applications that can rely on a specific class of such communications techniques, commonly referred to as molecular communications. In particular, we focus on health-related applications. This decision is due to the rapidly increasing interests of research communities and companies to minimally invasive, biocompatible, and targeted health-care solutions. Molecular communication techniques have actually the potentials of becoming the main technology for implementing advanced medical solution. Hence, in this paper we provide a taxonomy of potential applications, illustrate them in some detail, along with the existing open challenges for them to be actually deployed, and draw future perspectives

    Development of targeted therapeutic strategies for metastatic lung cancer

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    El cáncer de pulmón es el cáncer que se diagnostica con más frecuencia y la principal causa de muerte por cáncer en todo el mundo. Es importante destacar que alrededor del 75% de los pacientes son diagnosticados en estadios metastásicos avanzados, cuando la cirugía ya no es posible, lo que supone una caída dramática de la tasa de supervivencia a 5 años al 6%. El principal objetivo de esta tesis es definir nuevas estrategias terapéuticas inspiradas en la biología para pacientes con cáncer de pulmón metastásico. Para ello, se exploraron diferentes estrategias terapéuticas inspiradas en la biología del tumor, una de ellas proviene de los exosomas tumorales y la otra de las células que diseminan desde el tumor primario para formar las metástasis

    Escaping Antiangiogenic Therapy: Strategies Employed by Cancer Cells

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    IndexaciĂłn: Web of ScienceTumor angiogenesis is widely recognized as one of the hallmarks of cancer. Consequently, during the last decades the development and testing of commercial angiogenic inhibitors has been a central focus for both basic and clinical cancer research. While antiangiogenic drugs are now incorporated into standard clinical practice, as with all cancer therapies, tumors can eventually become resistant by employing a variety of strategies to receive nutrients and oxygen in the event of therapeutic assault. Herein, we concentrate and review in detail three of the principal mechanisms of antiangiogenic therapy escape: (1) upregulation of compensatory/alternative pathways for angiogenesis; (2) vasculogenic mimicry; and (3) vessel co-option. We suggest that an understanding of how a cancer cell adapts to antiangiogenic therapy may also parallel the mechanisms employed in the bourgeoning tumor and isolated metastatic cells delivering responsible for residual disease. Finally, we speculate on strategies to adapt antiangiogenic therapy for future clinical uses.http://www.mdpi.com/1422-0067/17/9/148

    The use of microfluidic technology for cancer applications and liquid biopsy

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    © 2018 by the authors. There is growing awareness for the need of early diagnostic tools to aid in point-of-care testing in cancer. Tumor biopsy remains the conventional means in which to sample a tumor and often presents with challenges and associated risks. Therefore, alternative sources of tumor biomarkers is needed. Liquid biopsy has gained attention due to its non-invasive sampling of tumor tissue and ability to serially assess disease via a simple blood draw over the course of treatment. Among the leading technologies developing liquid biopsy solutions, microfluidics has recently come to the fore. Microfluidic platforms offer cellular separation and analysis platforms that allow for high throughout, high sensitivity and specificity, low sample volumes and reagent costs and precise liquid controlling capabilities. These characteristics make microfluidic technology a promising tool in separating and analyzing circulating tumor biomarkers for diagnosis, prognosis and monitoring. In this review, the characteristics of three kinds of circulating tumor markers will be described in the context of cancer, circulating tumor cells (CTCs), exosomes, and circulating tumor DNA (ctDNA). The review will focus on how the introduction of microfluidic technologies has improved the separation and analysis of these circulating tumor markers

    Study of Circulating Tumor Cells using Microfluidic Technology: From Isolation to Analysis

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    An intimidating aspect of cancer is its ability to spread out to distant organs causing 90% of cancer-associated deaths. This metastatic progression is driven by circulating tumor cells (CTCs) shed from the primary tumor into bloodstream of carcinoma patients. As a result, CTCs hold great promise as a potential biomarker in areas of cancer diagnosis, monitoring, and evaluation of therapeutic efficacy for personalized medicine, which can serve as surrogate for invasive tissue biopsy. However, theses cells are extremely rare with a frequency of only 1-10 cells surrounded by billions of normal blood cells in 1mL of blood. This thesis delineates the shortcomings of existing CTC isolation methods followed by development and implementation of new microfluidic-based platforms to improve the sensitivity, specificity, and throughput for CTC enrichment. First, an affinity-based CTC isolation chip is introduced incorporating functional graphene oxide for high-density tumor specific antibody presentation. The two-dimensional surface-capture approach shows an overall CTC capture efficiency of >82.3% for flow rates up to 3mL/hr, while maintaining high viability (>90%) from low shear stress generated during sample processing. The extremely low blood cell contamination rate in the order of 100 cells/mL enables subsequent downstream analysis of CTCs. The clinical validity of the chip is demonstrated in a cohort of 47 metastatic breast cancer patients. Second, a size based CTC isolation chip is presented utilizing the inertial force effects to isolate CTCs by differentially focusing. Channel design parameters including the height, width, and radius of curvature and flow conditions are investigated to observe their effect on particle/cell focusing and streak migration. Optimal flow regimes to achieve maximum separation of 10/20 ÎĽm particles, representing leukocytes and CTCs respectively, in various channel configurations are identified. Based on these results, a cascaded spiral chip is designed for label-free CTC isolation achieving 87.76% recovery rate with 97.91% leukocyte depletion. Finally, a catheter based in-vivo CTC isolation system is implemented for large blood volume CTC screening. The system includes a dual lumen catheter to connect the patient blood veins, a peristaltic pump for continuous blood sampling, heparin injector to prevent blood clogging and clotting, and a CTC capture module.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/138501/1/tztaebo_1.pd

    Sensor-integrated microfluidic approaches for liquid biopsies applications in early detection of cancer

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    Cancer represents one of the conditions with the most causes of death worldwide. Common methods for its diagnosis are based on tissue biopsies the extraction of tissue from the primary tumor, which is used for its histological analysis. However, this technique represents a risk for the patient, along with being expensive and time-consuming and so it cannot be frequently used to follow the progress of the disease. Liquid biopsy is a new cancer diagnostic alternative, which allows the analysis of the molecular information of the solid tumors via a body fluid draw. This fluid-based diagnostic method displays relevant advantages, including its minimal invasiveness, lower risk, use as often as required, it can be analyzed with the use of microfluidic-based platforms with low consumption of reagent, and it does not require specialized personnel and expensive equipment for the diagnosis. In recent years, the integration of sensors in microfluidics lab-on-a-chip devices was performed for liquid biopsies applications, granting significant advantages in the separation and detection of circulating tumor nucleic acids (ctNAs), circulating tumor cells (CTCs) and exosomes. The improvements in isolation and detection technologies offer increasingly sensitive and selective equipment's, and the integration in microfluidic devices provides a better characterization and analysis of these biomarkers. These fully integrated systems will facilitate the generation of fully automatized platforms at low-cost for compact cancer diagnosis systems at an early stage and for the prediction and prognosis of cancer treatment through the biomarkers for personalized tumor analysis

    Carbon nanotubes micro-arrays: characterization and application in biosensing of free proteins and label-free capture of breast cancer cells

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    Circulating tumor cells (CTCs) are cells released into the bloodstream from primary tumors and are suspected to be one of the main causes behind metastatic spreading of cancer. The ability to capture and analyze circulating tumor cells in clinical samples is of great interest in prevailing patient prognosis and clinical management of cancer. Carbon nanotubes, individual rolled-up graphene sheets, have emerged as exciting materials for probing the biomolecular interactions. With diameter of about 1 nm, they can attach themselves to cell surface receptors through specific antibodies and hold a great potential for diagnostic cellular profiling. Carbon nanotubes can be either semiconducting or metallic, and the electronic properties of either type rivals the best known materials. Small size of nanotubes and the ability to functionalize their surface using 1-Pyrenebutanoic Acid, Succinimidyl Ester (PASE), enables a versatile probe for developing a platform for capture and analysis of cancer biomarkers and circulating tumor cells. Although nanotubes have previously been used to electrically detect a variety of molecules and proteins, here for the first time we demonstrate the label free capture of spiked breast cancer cells using ultra-thin carbon nanotube film micro-array devices in a drop of buffy coat and blood. A new statistical approach of using Dynamic Time Warping (DTW) was used to classify the electrical signatures with 90% sensitivity and 90% specificity in blood. These results suggest such label free devices could potentially be useful for clinical capture and further analysis of circulating tumor cells. This thesis will go in-depth the properties of carbon nanotubes, device fabrication and characterization methodologies, functionalization protocols, and experiments in buffy coats and in blood. Combination of nano and biological materials, functionalization protocols and advanced statistical classifiers can potentially enable clinical translation of such devices in the future
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