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Aptamers in Medical Diagnosis
Published in Rakesh N. Veedu, Aptamers, 2017
Veli Cengiz Ozalp, Murat Kavruk, Ozlem Dilek, Abdullah Tahir Bayrac
Microfluidic paper-based devices (μ-PAD) are low-cost alternative platforms for portable and disposable biosensors without dependence on sophisticated instrumentation. Paper-based cytodevices have been reported by chemiluminiscence, fluorescent, electrochemical, or Raman scattering. The formats for μ-PAD sensors have been primarily colorimetric or fluorescent signaling. Colorimetric devices are mostly semiquantitative; however, such yes/no biosensors are not adequate for cancer diagnosis. Likewise, fluorescent devices require advanced instrumentation. A recent report demonstrated that electrochemical detection in μ-PAD format could provide an advantageous device for portable and simple cancer detection [80]. Human acute promyelocytic leukemia is a deadly cancer condition that affects the blood and bone marrow. A gold-paper electrode was fabricated by the growth of a gold nanoparticle layer on the paper surface and employed as the working electrode. Leukemia cancer cells (HL-60) cell-targeting aptamers were immobilized on this Au-paper electrode. The electrochemical paper probe was used for cancer cell detection by the horseradish peroxidase–labeled FA integrated as the specific recognition of the folate receptor on the captured HL-60 cell surface by FA and the amplification of electrochemical signal based on the horseradish peroxidase–catalyzed oxidation of o-phenylenediamine by peroxide.
Immunomodulatory Activities of Silver Nanoparticles (AgNPs) in Human Neutrophils
Published in Huiliang Cao, Silver Nanoparticles for Antibacterial Devices, 2017
PMNs are the most abundant type of leukocytes in human blood, representing more than 65% of total leukocytes. These cells are primordial players of innate immunity and provide a very effective defense against pathogens, especially bacteria and fungus. They are terminally mature nondividing cells that, as other immune cells, develop in the bone marrow from CD34+ stem cells. Importantly, more than 50% of the bone marrow is dedicated to the generation of PMNs. It takes approximately 14 days to obtain fully mature PMNs from precursor cells resulting from a series of cell divisions and stages: myeloblasts, promyelocytes, myelocytes, metamyelocytes, band neutrophils and mature neutrophils. Although the mechanism is still not well understood, it occurs under the influence of regulatory cytokines (Edwards and Hallett 1997; Edwards and Watson 1995; Ward et al. 1999). In a normal adult, it has been estimated that approximately 5 × 1010 neutrophils are released from the bone marrow per day, representing one of the fastest cell turnovers in the human body (Edwards and Watson 1995; Ward et al. 1999). Therefore, it is easy to imagine that PMN cell turnover must be under strict control in order to prevent cell overproduction leading to diseases, including cancer. Indeed, one type of cancer, acute promyelocytic leukemia, is a cancer of the white blood cells characterised by an abnormal accumulation of immature neutrophils, the promyelocytes. In healthy individuals, the number of PMNs remains relatively constant, and this could be explained by the fact that these cells possess a short lifespan with a half-life of ~12 h in circulation. Further, PMNs are well known to undergo constitutive or spontaneous apoptosis, certainly largely responsible for maintaining adequate cell number under normal circumstances. Apoptotic PMNs become unresponsive to extracellular stimuli and will lose and express different kinds of molecules on their surfaces (Akgul et al. 2001; Duffin et al. 2010; Ren and Savill 1998), including some named as ‘eat-me’ signals involved in the elimination of apoptotic PMNs by professional phagocytes (a process called efferocytosis), largely responsible for the resolution of inflammation (Akgul et al. 2001; Duffin et al. 2010; Savill 1997; Silva 2010). Therefore, identification of any agents that could induce or delay PMN apoptosis is of major importance to help control the number of PMNs. In this respect, when the rate of PMN apoptosis is accelerated, this could increase bacterial susceptibility, and inversely, when apoptosis is delayed or suppressed, this could aggravate inflammation and lead to autoimmune diseases (Duffin et al. 2010; Savill 1997).
Phytochemical and biological characterization of aqueous extract of Vassobia breviflora on proliferation and viability of melanoma cells: involvement of purinergic pathway
Published in Journal of Toxicology and Environmental Health, Part A, 2023
Altevir Rossato Viana, Nathieli Bianchin Bottari, Vinícius Rodrigues Oviedo, Daniel Santos, James Eduardo Lago Londero, Maria Rosa Chitolina Schetinger, Erico Marlon Moraes Flores, Aline Pigatto, André Passaglia Schuch, Alexandre Krause, Luciana Maria Fontanari Krause
The results of cell viability assays involving three different methods were similar but variation existed between may be accounted for by Masson-Meyers, Bumah, and Enwemeka (2016), who found greater sensitivity with MTT in detecting cell viability in a study with human dermal fibroblasts compared to trypan blue and neutral red. In our investigation, incubation with V. breviflora extract required a concentration of 0.57 mg/ml to decrease cell viability by 50% in the mouse B16-F10 cell line. Viana et al. (2022) noted a higher concentration of the hexane extract of V. breviflora was necessary to reduce viability of cell lines including mouse B16-F10 (610.41 μg/ml), human cervical cancer HeLa (1.031 μg/ml), human adenocarcinoma epithelial A549 (1.173 μg/ml), human malignant gliomablastoma U87MG (777.7 μg/ml), human acute promyelocytic leukemia NB4 (973 μg/ml) and human hepatocellular carcinoma HepG2 (979 μg/ml).
Structurally improved reduced graphene oxide nanocluster structured assembly with Naringin for the effective photothermal therapy of colon tumour patients and nursing care management
Published in Molecular Physics, 2020
Liwei Han, Juan Tan, Jing Li, Tianyu Meng, Yuhang Wang, Sisi Wang
Chemotherapy is a vital clinical therapeutic modality for an extensive variety of cancers for intense acute promyelocytic leukemia and lung cancer. Though, the less therapeutic efficacy due to the drug resistance, low cellular uptake efficacy, and enhanced side effects such as liver and kidney damage, hair loss, nausea and cardiac toxicity limit the clinical applications of chemotherapy. So, target selective drug delivery with high efficiency, low toxicity and minimal side effects has been developed to improve the efficacy of chemotherapeutics. On the other hand, near-infrared (NIR) photothermal therapy based on nanoparticles provides a promising treatment strategy for efficient tumour ablation with minor injury to the surrounding tissue. A wide variety of nanoparticles including graphene, carbon nanotubes, liposome, polymers or gold nanospheres have been employed to photothermal therapy due to their strong absorbance in the NIR region [16–20]. Combination chemotherapy and photothermal therapy have been established to be an active strategy to enhance the efficiency of cancer treatment and to diminish the drug resistance. Nevertheless, non-targeted delivery of drugs and heat to the tumour site can lead to undesired side effects to normal tissues [6,15,21].