Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Structural features of Fab fragments of rheumatoid factor IgM-RF in solution.

The structural features of the Fab fragments of monoclonal (Waldenstrom's disease) immunoglobulin M (I-M) and rheumatoid immunoglobulin M (lgM-RF) were studied by a complex of methods, including small-angle X-ray scattering (SAXS), electron spin resonance (ESR), and mass spectrometry (MS). The Fab-RF fragment was demonstrated to be much more flexible in the region of interdomain contacts, the molecular weights and the shapes of the Fab and Fab-RF macromolecules in solution being only slightly different. According to the ESR data, the rotational correlation time for a spin label introduced into the peptide sequence for Fab is twice as large as that for Fab-RF (21 +/- 2 and 11 +/- 1 ns, respectively), whereas the molecular weights of these fragments differ by only 0.5% (mass-spectrometric data), which correlates with the results of molecular-shape modeling by small-angle X-ray scattering. The conclusion about the higher flexibility of the Fab-RF fragment contributes to an understanding of the specificity of interactions between the rheumatoid factor and the anti-ens of the own organism. © 2008, Springer