Dialdehyde starch-cross-linking agent for biomedical applications

Abstract

Polysaccharides are an important class of biological polymers joined by glycosidic bonds, universally found in all living organisms. Due to their diversity of structures and their properties, polysaccharides constitute interesting sources of materials that can be used as in many fields of science and industry. They are biocompatible, non-toxic, biodegradable, and wide availability in nature. To the most commonly known and available polysaccharide is starch. Starch is a polymer consisting residue of α-D-glucose units. In fact the polysaccharide is not a chemically uniform compound. It consists of unbranched amylose and branched amylopectin. The native and modified starch are both used for food and other applications such as textile industries, pharmaceutics, and drug delivery systems. Controlled periodate oxidation of polysaccharides results in partial oxidation of the hydroxyl groups on carbons 2 and 3. The partial oxidation of these groups leads to the rupture of bond between carbons 2 and 3 and to the formation of two aldehyde groups in each oxidized monomeric units. Dialdehyde polysaccharides have found wide application in tissue engineering, the food industry, and in biomedical applications, where they perform the function of cross-linking agents. In this study, potato and corn starch were oxidized by sodium periodate to prepare a dialdehyde functionalized material. The obtained modified starches have been characterized with chemical analysis, scanning electron microscopy, and ATR-FTIR spectroscopy. The samples were exposed to high-energy ultraviolet radiation and the photochemical reaction was monitored by ATR-FTIR spectroscopy. The surface properties of native and dialdehyde starches before and after UV irradiation were determined by measuring the contact angles and calculating the surface free energy. The crystallinity of the samples were characterized by X-ray diffractometry (XRD).

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The project was supported by research grant: National Science Centre 2014/15/D/NZ7/01805