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Polymeric Nanoparticles for Drug Delivery
Published in Severian Dumitriu, Valentin Popa, Polymeric Biomaterials, 2020
Karine Andrieux, Julien Nicolas, Laurence Moine, Gillian Barratt
Although many of the targeted delivery systems described earlier are destined for intravenous administration, the possibility of targeting by other routes has not been ignored. In particular, different targeting systems have been proposed to increase bioadhesion by the oral route. One approach is the use of specific lectins to promote binding to particular sugars in the mucus or on the intestinal cell surface (Lehr and Puzstai, 1995, Irache et al., 1996, Russell-Jones et al., 1999, Clark et al., 2000). The biotin–avidin system is a convenient way of attaching lectins to NPs (Gref et al., 2003, Weiss et al., 2007). Lectin-mediated targeting has been used, for example, to deliver antigens across Peyer’s patches for oral immunization (Gupta et al., 2007).
Proteins and proteomics
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2018
Many ligand transport proteins bind specific small biomolecules and transport them to other locations in the body of a multicellular organism. These proteins must have a high binding affinity when their ligand is present in high concentrations but must also release the ligand when it is present at low concentrations in the target tissues. The canonical example of a ligand-binding protein is hemoglobin, which transports oxygen from the lungs to other organs and tissues in all vertebrates and has close homologues in every biological kingdom. Lectins are sugar-binding proteins, which are highly specific for their sugar moieties. Lectins typically play a role in biological recognition phenomena involving cells and proteins. Receptors and hormones are highly specific binding proteins. Transmembrane proteins can also serve as ligand transport proteins that alter the permeability of the cell membrane to small molecules and ions. The membrane alone has a hydrophobic core through which polar or charged molecules cannot diffuse. Membrane proteins contain internal channels that allow such molecules to enter and exit the cell. Many ion channel proteins are specialized to select for only a particular ion. For example, potassium and sodium channels often discriminate for only one of the two ions.
Innovations in Noninvasive Instrumentation and Measurements
Published in Robert B. Northrop, Non-Invasive Instrumentation and Measurement in Medical Diagnosis, 2017
Lectins are proteins that have specific binding activity toward the carbohydrate residues of glycoproteins and glycolipids such as those found on cell surface membranes. On example of a glycated protein is HbA1c (glycated hemoglobin (Hb) in erythrocytes), an indicator of present and past blood glucose levels. Over 300 lectins have been identified in a variety of species, ranging from viruses and bacteria to plants and animals. The lectin sugar-binding proteins can be classified into five groups according to the monosaccharide to which they have the highest affinity: (1) Mannose; (2) Galactose/N-acetylgalactosamine; (3) N-acetylglucosamine; (4) Fucose; and (5) Sialic acid. “These proteins, which function as recognition molecules in cell–molecule and cell–cell interactions, have been implicated in a number of essential biological processes including cell proliferation, cell arrest, apoptosis, tumor cell metastasis, leukocyte homing and trafficking, and especially microbial (viral and bacterial) infection” (Hu and Wong 2009).
The emergence of nanoporous materials in lung cancer therapy
Published in Science and Technology of Advanced Materials, 2022
Deepika Radhakrishnan, Shan Mohanan, Goeun Choi, Jin-Ho Choy, Steffi Tiburcius, Hoang Trung Trinh, Shankar Bolan, Nikki Verrills, Pradeep Tanwar, Ajay Karakoti, Ajayan Vinu
Redox responsiveness can be initiated through several other gated channels. Zhou et al. used the protein-carbohydrate recognition as a gating factor for redox responses and the corresponding drug release from MSN. The study utilised the lectin gated mesoporous glyconanoparticles. Lectins are non-immunogenic proteins that can interact with carbohydrates. The fluorescent MSN were functionalised with D-mannose using a photochemical nitrene-mediated approach and then modified again with redox-sensitive disulphide linkers (Figure 10C). These linkers were further attached with the per fluorophenyl azide (PFPA) groups for the glutathione responsive drug release [342]. The cell internalization studies and the release profile of the DOX from the gated MSN in lung cancer cells have been confirmed using further FITC conjugation (Figure 10D, 10E). The high glutathione concentration in the tumours destroyed the lectin gatekeepers and released the drug to the environment, resulting in 61% of drug release in 7 hours. These recent studies demonstrated a trend towards developing biological components and their hybrids for drug delivery due to the reduction in side effects.
Aqueous two phase partitioning of Pisum sativum lectin in PEG/citrate salt system
Published in Preparative Biochemistry and Biotechnology, 2018
Rashmi Bommenahalli Shashidhara, Regupathi Iyyaswami
Lectin is a protein of non-immune origin which is different from other plant proteins due to its higher degree of specificity and reversible binding capacity to carbohydrates. A wide variety of applications are exploited based on the carbohydrate specificity of lectin. Even though lectin is widely distributed among plants, animals, and microorganisms, the legume seeds are considered as the richest source of lectins.[1] The demand for different types of lectins from different sources is drastically increasing due to their potential application in various fields such as lectins in diagnostics—agricultural and food industry, environmental detection,[2] medical sample analysis,[3] lectin in separation and characterization of glycoproteins and glycopeptides—lectin-based affinity tag for one-step protein purification,[4] glycan profiling,[5] and therapeutic applications of lectins—diagnosis of malignant tumors,[6] drug delivery,[7] antiviral, immunomodulatory activity, and antifungal activity.[8]
Purification of a lectin from Cratylia mollis crude extract seed by a single step PEG/phosphate aqueous two-phase system
Published in Preparative Biochemistry & Biotechnology, 2020
Cynthia Oliveira Nascimento, Romero Marcos Pedrosa Brandão Costa, Paulo Antônio Soares, Polyanna Nunes Herculano, Tatiana Souza Porto, Thiago Pajeú Nascimento, Carolina de Albuquerque Lima, Raquel Pedrosa Bezerra, José Antônio Teixeira, Luana Cassandra Breitenbach Barroso Coelho, Maria Tereza dos Santos Correia, Maria das Graças Carneiro-da-Cunha, Ana Lúcia Figueiredo Porto
Various proteins have the capacity to recognize specifically and reversely different substances in organisms. Well-known examples are proteins able to bind to substrates or inhibitors that can specifically recognize an epitope at the surface of a cell membrane.[1] Lectins are carbohydrate-binding proteins with substantial structural diversity in the biology world; they bind selectively and non-covalently to carbohydrate residues and are involved in several biological processes and activities like antibacterial and antifungal assays.[2]