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Introduction to Cancer, Conventional Therapies, and Bionano-Based Advanced Anticancer Strategies
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
Some of the cells found in the tumor microenvironment interact with the tumor to promote its growth. For instance, tumor-associated macrophages (TAMs) are found to be pro-tumorigenic as they are implicated in the migration, invasion, and metastasis of malignant cells. Studies have shown that an abundance of TAMs in the tumor microenvironment is linked to a poor prognosis. TAMs are also the main contributors to tumor angiogenesis. Furthermore, in hypoxic areas of tumors, TAMs are found to accumulate there due to the release of hypoxia-induced chemo-attractants. Other cells found in the tumor microenvironment and that are associated with tumor development are tumor-associated neutrophils (TANs). There is evidence that TANs contribute to tumor growth and metastasis. In addition, studies have shown that TANs have a pro-tumorigenic effect by suppressing the immune system and enhancing angiogenesis. Cancer-associated fibroblasts (CAFs) arise from residential fibroblasts that differentiate into myofibroblasts, during tissue injury. Studies have shown that CAFs increase the risk of development of malignant cells. In addition, the arrangement of CAFs in the tumor microenvironment enables them to restrict the ability of the chemotherapeutic agents from reaching malignant cells [62].
Metal-Based Nanoparticles and the Immune System: Activation, Inflammation, and Potential Applications
Published in Raj Bawa, János Szebeni, Thomas J. Webster, Gerald F. Audette, Immune Aspects of Biopharmaceuticals and Nanomedicines, 2019
Yueh-Hsia Luo, Louis W. Chang, Pinpin Lin
During acute inflammation, polymorphonuclear neutrophil cells (PMNs) are the first type of leukocytes to migrate to an inflammatory site and then produce several proinflammatory mediators including chemokines, which further attract other PMNs and other cell types like monocytes-macrophages and lymphocytes, corresponding to chronic inflammation. Gold nanoparticles were found trapped by neutrophils in their extracellular traps (NETs), being composed mainly of DNA and a variety of antibacterial proteins [61]. The cell-gold networks were visible after as early as 15 min of treatment of neutrophils with the gold nanoparticles. NETs may contribute to alerting the immune system of a danger signal by activating DNA receptors such as TLR9. This activation might turn out to help in the recruitment of immune cells to mount an acquired immune response or to resolve the inflammation. NETs can either fight inflammatory disease or cause disease depending on the place, time, and dose [62]. However, NETs triggered by nanoparticles need further investigation to figure out their physiological roles. Wang et al. found that the delivery of drugs into inflammatory neutrophils by nanoparticles can prevent vascular inflammation [63]. This study provides a novel nanoparticle-based therapeutic approach for targeting activated neutrophils to treat a range of inflammatory disorders.
Biomaterial Surface Properties
Published in Nihal Engin Vrana, Biomaterials and Immune Response, 2018
Tuğba Endoğan Tanır, Güneş Esendağlı, Eda Ayşe Aksoy
Polymorphonuclear neutrophils (PMN) are the most abundant type of leukocytes in the blood. Even though they have a short life-span, they are a vital part of the immune system. PMNs are the most motile leukocytes with their high capacity to easily travel through the stroma and they are usually the first to reach to the site of injury, especially in the acute phase of inflammation. Neutrophils respond to any type of stress including infections, cancer, trauma, heat changes, sterile inflammation, changes in the oxygen levels and pH and other disorders and disruptions of homeostasis. Similar to other phagocytic cells (i.e., macrophages), neutrophils are indispensable in fighting against extracellular bacteria through phagocytosis, releasing reactive molecules and enzymes to remove the invading microorganisms. In the context of biomaterials, neutrophils are also one of the first cell types that interact with biomaterial surfaces upon implantation.
Acute toxicity and health effect of perfluoroisobutyronitrile on mice: a promising substitute gas-insulating medium to SF6
Published in Journal of Environmental Science and Health, Part A, 2020
Xiaoxing Zhang, Fanchao Ye, Yi Li, Shuangshuang Tian, Baojuan Xie, Yadong Gao, Song Xiao
Table 3 shows the blood cell test results of mice after exposure. It can be found that the lymphocytes percentage of mice that died at a concentration of 1202 ppm significantly decreased and the neutrophils percentage increased significantly, which are all deviated from the reference value. Neutrophils belong to a type of white blood cells that play an important role in the immune system. A high percentage of neutrophils are common in acute inflammation. Lymphocytes can produce and carry antibodies and prevent viral infections. The decrease in lymphocyte percentage is common in immunodeficiency diseases, which indicates that acute inhalation of C4F7N gas within 4 h will cause inflammation and decline of immune system function. In addition, the number of red blood cells and hemoglobin that transport oxygen through blood in the animal in the dead mice at 1202 ppm is high, which is due to the impaired heart and lung function of the mice (the clinical manifestation is that the mice have shortness of breath).