02266nas a2200229   4500008004100000022001400041245015400055210006900209260009900278300001200377490000800389520136000397653002101757653001401778653001801792653000801810653001001818100002501828700003501853700002301888856012501911       2014                        eng d  a0144-861700aSupramolecular transitions in native cellulose-I during progressive oxidation reaction leading to quasi-spherical nanoparticles of 6-carboxycellulose0 aSupramolecular transitions in native celluloseI during progressi  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcNOV  a615-6230 v1133 a<p>Cellulose-I swells considerably in phosphoric acid, and converts to amorphous cellulose via a cellulose-II transition state. Controlled oxidation of cellulose-I to 6-carboxycellulose (6CC) using HNO3-H3PO4-NaNO2 oxidation system led to the selective production of 6CC's of varying carboxyl contents (1.7-22%) as well as various shapes and sizes (macro-sized fibrils of several micron length and/or spherical nanoparticles of 25-35 nm), depending on the reaction conditions. 6CC's having less than 14% carboxyl content were largely in cellulose-II form (WAXRD values in-between cellulose I and cellulose II), whereas at 14-22% the 6CC's were largely amorphous; only trace crystallinity was observed at 19% and 22% carboxyl 6CC. Spherical nanoparticles retained a high degree of crystallinity having cellulose-I structure, whereas the macro-sized fibrils were largely converted to cellulose-II structure. Analysis by WAXRD as well as by CP-MAS C-13 NMR studies gave similar conclusions. Reduced molecular weight with progressive oxidation, including presence of oligomers, was also evident from an increase in the reducing-end carbon peak at similar to 92 ppm. For high oxidation levels (&gt;14%) the NMR 92-96 ppm peaks disappeared on extracting with dilute alkali, due to soluble oligomers being removed. (C) 2014 Elsevier Ltd. All rights reserved.</p>10aCarboxycellulose10acellulose10aNanoparticles10aNMR10aWAXRD1 aSharma, Priyanka, R.1 aRajamohanan, Pattuparambil, R.1 aVarma, Anjanikumar  uhttps://library.ncl.res.in/content/supramolecular-transitions-native-cellulose-i-during-progressive-oxidation-reaction-002057nas a2200241   4500008004100000022001400041245009800055210006900153260007300222300001200295490000700307520118200314653001901496653001401515653002801529653002401557100002501581700001801606700001901624700001901643700002301662856013001685       2016                        eng d  a0141-813000aShape and size engineered cellulosic nanomaterials as broad spectrum anti-microbial compounds0 aShape and size engineered cellulosic nanomaterials as broad spec  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a460-4650 v873 a<p>Oxidized celluloses have been used for decades as antimicrobial wound gauzes and surgical cotton. We now report the successful synthesis of a next generation narrow size range (25-35 nm) spherical shaped nanoparticles of 2,3,6-tricarboxycellulose based on cellulose I structural features, for applications as new antimicrobial materials. This study adds to our previous study of 6-carboxycellulose. A wide range of bacteria such as Escherichia coli, Staphloccocus aureus, Bacillus subtilis and Mycobacterium tuberculosis (non-pathogenic as well as pathogenic strains) were affected by these polymers in in vitro studies. Activity against Mycobacteria were noted at high concentrations (MIC99 values 250-1000 mu g/ml, as compared to anti-TB drug Isoniazid 0.3 mu g/ml). However, the broad spectrum activity of oxidized celluloses and their nanoparticles against a wide range of bacteria, including Mycobacteria, show that these materials are promising new biocompatible and biodegradable drug delivery vehicles wherein they can play the dual role of being a drug encapsulant as well as a broad spectrum anti-microbial and anti-TB drug. (C) 2016 Published by Elsevier B.V.</p>10aAnti-microbial10acellulose10aSpherical nanoparticles10aTricarboxycellulose1 aSharma, Priyanka, R.1 aKamble, Sunil1 aSarkar, Dhiman1 aAnand, Amitesh1 aVarma, Anjanikumar  uhttps://library.ncl.res.in/content/shape-and-size-engineered-cellulosic-nanomaterials-broad-spectrum-anti-microbial-compounds