Bacterial Cellulose Film Produced by Gluconacetobacter hansenii as a Source Material for Oxidized Nanofibrillated Cellul
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Bacterial Cellulose Film Produced by Gluconacetobacter hansenii as a Source Material for Oxidized Nanofibrillated Cellulose M. S. Rubinaa,*, M. A. Pigalevab, A. V. Naumkina, and T. I. Gromovykhc Presented by Academician A.R. Khokhlov, May 7, 2020 Received May 8, 2020; revised May 25, 2020; accepted June 15, 2020
Abstract—Nanofibrillated cellulose was obtained according to the TEMPO-mediated oxidation protocol. Bacterial cellulose produced by Gluconacetobacter hansenii served as the starting material for oxidation. The oxidation gave a stable aqueous dispersion of a novel form of nano-cellulose, which was used to cast a film. It was found that the oxidized bacterial cellulose film is formed by fibrils with an average width of ~6 nm and a length from 300 nm to several micrometers. The presence of carboxyl groups on the film surface was confirmed by IR and X-ray photoelectron spectroscopy. Keywords: nanofibrillated cellulose, bacterial cellulose, oxidation DOI: 10.1134/S0012501620080023
Nanofibrillated cellulose (NFC) is a nanostructured cellulose material with characteristic size of constituent units of 100 nm (width) and 1–10 μm (length) [1]. This nano-scale cellulose has a large aspect ratio (fibril length to width ratio), which gives rise to quite a few unique mechanical, rheological, and barrier properties. NFC is used as a drug carrier, film coating, and porous material for wound healing in regenerative medicine. An efficient method for the production of NFC is oxidation of cellulose with sodium hypochlorite in alkaline medium mediated by (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). It is known that TEMPO-mediated oxidation of polysaccharides is regioselective and can be used to oxidize primary alcohol groups in the polysaccharide unit to aldehyde or carboxyl groups under mild conditions at room temperature and normal pressure [2]. In the method proposed previously [3], in which TEMPO/NaClO/NaBr was used as the oxidative system at pH 10, virtually all primary alcohol groups at C6 atoms of the cellulose polysaccharide units were a Nesmeyanov
Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, 119991 Russia b Physical Faculty, Moscow State University, Moscow, 119991 Russia c Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, 119991 Russia *e-mail: [email protected]
oxidized to carboxyl groups. The oxidized nanofibrillated cellulose (ONFC) obtained in this way and ONFC-based materials can be used for medical purposes, in particular, as hemostatic drugs for the treatment of acute and chronic skin wounds and as drug fillers and carriers in pharmaceutical industry [4]. Bacterial cellulose (BC) is the product of biosynthesis of some bacterial strains, of which Acetobacter xylinum or Gluconacetobacter xylinum producer strains are used most often [5]. Unlike plant cellulose, BC has a higher degree of purity, crystallinity, and hydrophilic properties, which makes it useful for regenerative medicine [6].
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