Carbohydrate Nanotechnology and its Applications for the Treatment of Cancer

Carbohydrate-functionalized Liposomes in Cancer Therapy

“…Many tumors exhibit increased glucose uptake. Several theories have been presented to explain this exacerbated glucose consumption including, the increase of hexokinase (HK) expression, the expression of modified glycan chains, the decrease of glucose-6-phosphatase (G6P) mediated glucose dephosphorylation, and the overexpression of sugar transporters [17][18][19]. The following sections detail each of the presented explanations.…”

“…The different classes of glycoconjugates include glycosphingolipids, proteoglycans, and glycoproteins. Some of the processes controlled by glycans in eukaryotic cells include protein folding, cell signaling, pathogen recognition, inflammation, tissue organization, and cell proliferation [16,18] Glycosylation is an enzymatic process that links saccharides to other saccharides, proteins or lipids [24]. Proteins can be glycosylated by the covalent attachment of a saccharide to a polypeptide backbone via nitrogen or oxygen linkages (N-linkage to asparagine or an O-linkage to serine or threonine).…”

“…Liposomes are biocompati-ble, biodegradable, non-toxic, and non-immunogenic. Moreover, liposomes have both lipophilic and aqueous environments making them useful for delivering hydrophobic, amphipathic, and hydrophilic drugs [18,35,36] Liposomal surface functionalization unlocks the enormous potential in the application of liposomes. Various biomolecules have been conjugated to liposome surfaces for a variety of biomedical applications.…”

“…The presence of PEG also helps reduce vesicle aggregation, thus enhancing the stability of the liposomal formulations [37]. Carbohydrate-functionalized liposomes have been used to study carbohydrate-carbohydrate recognition events; however, the primary application of glycan-coated liposomes is to direct the targeted liposomes to cells or tissues where carbohydrate-binding proteins are upregulated [18] Lectins are carbohydrate-binding proteins that are highly specific for sugar groups of other molecules [38]. A number of cells express the lectin receptors on their surfaces; hence when carbohydrate moieties are conjugated to liposomes, the resultant glycosylated vehicles will be recognized and endocytosed by lectin receptors [39].…”