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)

'Border' and 'Tehran' 2006

'Border' and 'Tehran 2006' are two related parts of a photographic project on Iran dealing with hardship and isolation on both sides of the border. 'Border' comprises twelve photographs (size 4'x6'). 'Tehran 2006' is one panoramic image (size 4'x10') which combines ten images. ‘Border’ focuses on untold stories of Iranians in exile. Using the codes of documentary, yet avoiding the usual generic approach, ‘Border’ combines fact and fiction. Reminiscent of movie posters, the work concentrates on the fantasy of return, using Beckett’s notion of waiting in ‘Waiting for Godot’ as a metaphor for the bleak situation facing Iranians today. Set against the cityscape of post–revolution Iran, ‘Tehran 2006’ focuses on the reality of the ordinary in extraordinary times. The project eschews the usual representations of Iran such as social documentary, abstract photography, or exotica. Instead, it echoes contemporary Iranian cinema, using non- actors and focusing on an apparently ‘small’ subject, treated allegorically to allude to wider social issues. Together, the projects deal with hardship and isolation on both sides of the border, challenging the fantasies Iranians have of both East and West. Those living in Iran idealize life in the West; those living outside long for ‘home’. But both groups share the will to survive - evident in the stories participants told Tabrizian - seeing survival as a strategy of resistance. These are large-scale productions akin to film shoots, with high production values and meticulous research. Tabrizian is creative author and director, assisted by Golding (lighting) and Nava (producer). Both projects were funded by AHRC (Small Grants and Research Leave) and ACE (total £6000). ‘Tehran 2006’ was purchased for Moderna Museet’s permanent collection, auctioned at Christies, Dubai (November 2007), and will show at Tate Modern 2008. Both projects were discussed at Tate Modern conference ‘Global Photography Now’ (Sept 2006). Images and related essays were published in Portfolio No 44 (‘Border’ alongside Hamid Naficy essay); Next Level, No.2 Vol 5 (‘Tehran’ alongside Tabrizian essay); New Formations, No. 62 (forthcoming

Resveratrol, curcumin and gallic acid attenuate glyoxal-induced damage to rat renal cells

Glyoxal (GO), a by-product of glucose auto-oxidation, is involved in the glycation of proteins/ lipids and formation of advanced glycation (AGE) and lipoxidation (ALE) end products. AGE/ALE were shown to contribute to diabetic complications development/progression such as nephropathy. Diabetic nephropathy progression has an oxidative nature. Given the antioxidant effects of polyphenols, potential protective effects of resveratrol, curcumin and gallic acid, in rat renal cells treated with GO, were evaluated in the present work. According to our results, incubation of GO with the cells reduced their viability and led to membrane lysis, reactive oxygen species (ROS) formation, lipid peroxidation, mitochondrial membrane potential collapse, and lysosomal membrane leakage. These findings were prevented by pre-treatment with resveratrol, curcumin and gallic acid. Mitochondrial and lysosomal toxic interactions appear to worsen oxidative stress/cytotoxicity produced by GO. Resveratrol, curcumin and gallic acid inhibited ROS formation and attenuated GO-induced renal cell death. © 2020 The Author(s