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Introduction to the Biological System
Published in Ashutosh Kumar Dubey, Amartya Mukhopadhyay, Bikramjit Basu, Interdisciplinary Engineering Sciences, 2020
Ashutosh Kumar Dubey, Amartya Mukhopadhyay, Bikramjit Basu
Tissue is a self-assembly of groups of cells having a similar structure and origin, which together perform a specific function. Various cell types and their functionality are summarized in Table 8.1. Based on the structure and function, tissues are classified into four major types, connective tissue, muscle tissue, nervous tissue, and epithelial tissue. Among these, the connective tissues consist of fibrous tissues embedded in ECM and provide structural framework to an organ. Connective tissue also contains spindle-shaped fibroblasts. Bone, adipose tissues, tendon, ligament, and blood are classical examples of connective tissues. As shown in Figure 8.5, the muscle tissue consists of muscle cells which have contractile nature that produce force and control the motion (movement or locomotion) in an organism. Among different types of muscle tissues, smooth muscle constitutes the inner linings of hollow organs like digestive tracts, blood vessels, etc., while the skeletal muscle are found to be attached to bone. Another type of muscle tissue is cardiac muscle, which is found only in the heart, has self-contracting nature that helps in rhythmic blood pumping throughout an organism. The neural tissue consists of neurons and neuroglia. In the central and peripheral nervous system, the nerve tissue constitutes the brain and spinal cord, and cranial nerves and spinal nerves, respectively. The epithelial tissues consist of closely packed epithelial cells, which cover the outer and inner surfaces of the organ.
Identifying Nanotoxicity at the Cellular Level Using Electron Microscopy
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
Kerry Thompson, Alanna Stanley, Emma McDermott, Alexander Black, Peter Dockery
Epithelial tissue, or epithelium (which comes from the Latin meaning ‘upon sheets’) is found covering surfaces of the body that either come into contact with the exterior or line the internal tubes and cavities. The initial interaction of nanoparticles with cells in an in vivo system tend to be primarily with epithelial cells. Moreover, many nanotoxicological studies at the ultrastructural level using EM will use epithelial cells in culture to classify and investigate the interaction at the bio-nano interface (Muhlfeld et al., 2007b, Ye et al., 2015). All epithelia are avascular but adhere to a vascularised bed of connective tissue, with the two layers being separated by an intermediate layer known as the basement membrane, which is generally manufactured by and secreted from the epithelial cells themselves. Epithelial cells display three key characteristics: cells are tightly bound together to form these sheet-like structures through junctional complexes; there are functionally different membrane domains within the cell (apical, basal, and lateral), and cells adhere to the underlying basement membrane (Gray et al., 1995, Ross, 1995, Young and Wheater, 2006). Therefore, they present the ideal model system for studying nanoparticle uptake.
Magnetic Separation in Integrated Micro-Analytical Systems
Published in Nguyễn T. K. Thanh, Clinical Applications of Magnetic Nanoparticles, 2018
Many types of cancer are categorized as a carcinoma, where tumours develop from epithelial cells. EpCAM is a type of molecule that mediates cell–cell adhesion in epithelia. Because EpCAM is exclusively found in epithelial cells and not in blood cells, it is very commonly used to separate circulating epithelial cells, which are most likely tumour cells. Currently, EpCAM may be the only successful biomarkers that can be used to separate many types of tumour cells. A problem associated with the use of EpCAM is EMT, which is a cellular process where epithelial cells lose cell–cell adhesion and polarity and gain properties similar to mesenchymal cells. Carcinoma cells often lose cell–cell adhesion, meaning they lose EpCAM expression. Some types of tumour cells that have gone through EMT are known to escape EpCAM-based screening. Other types of biomarkers used for CTC separation include human epidermal growth factor receptor 2 (HER2) for breast cancer cells and prostate-specific antigen for prostate cancer cells. Because they are also found in normal cells, they are not as an efficient marker as EpCAM in terms of the purity of selection. In CTC detection, they are often used as an additional antibody in combination with the use of EpCAM.
Disinfection of Human Amniotic Membrane Using a Hydrodynamic System with Ozonated Water
Published in Ozone: Science & Engineering, 2023
Sílvia Móbille Awoyama, Henrique Cunha Carvalho, Túlia de Souza Botelho, Sandra Irene Sprogis Dos Santos, Debora Alicia Buendia Palacios, Sebastian San Martín Henríque, Renato Amaro Zângaro, Carlos José de Lima, Adriana Barrinha Fernandes
Figure 5 shows the histological images obtained from the hAM samples in natura (A, B); samples submitted to 10 minutes of disinfection (C, D) and 15 minutes (E, F) of disinfection with ozonated water. Because 5 minutes (1.95 mg/cm2 (O3)) of sample disinfection was only partially effective, only the samples disinfected for 10 and 15 (3.9 and 5.85 mg/cm2 (O3)) minutes were considered for analysis. The results showed that the samples (Figure 5a, Figure 5b) had preserved cuboidal epithelial cells (a), basement membrane (b) stroma (c) and the presence of fibroblasts. Samples (Figure 5c, Figure 5d) showed preserved round epithelial cells (a) and presence of intercellular spaces, basement membrane (b), stroma (c) and the presence of fibroblasts (d). Samples (Figure 5e, Figure 5f) showed undefined and degenerated (a) epithelial cells and the presence of numerous intracellular spaces. The others structures were preserved.
Decellularized inner body membranes for tissue engineering: A review
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Ilyas Inci, Araz Norouz Dizaji, Ceren Ozel, Ugur Morali, Fatma Dogan Guzel, Huseyin Avci
Decellularized body membranes are promising tools to utilize in tissue engineering applications. As described in details in the previous parts of this review, decellularized forms of epithelial membranes and connective tissue membranes have been used in tissue engineering for preparation and regeneration of tissues such as tendon, skin, cornea, bone, cartilage, ocular surface, uterine, periodontium, vascular and cardiovascular. Even though, there are many studies have been performed in order to develop methods for decellularization, further improvement of decellularization agents is required for more effective cell removal and less destructive properties on tissue structures and ECM. In addition, development of decellularization agents which target in particular removal of MHC and α-gal antigens is also essential because these structures are one of the main reasons of tissue-organ rejections in allogeneic and xenogeneic tissue-organ implantations [206]. Moreover, in most cases there are reductions in the mechanical properties of tissues after decellularization therefore combination of decellularized membranes with synthetic biomaterials could be used to improve mechanical properties of decellularized membranes as described in some of the previous studies [53,109].