Chitosan is a biodegradable, biocompatible and non-toxic natural polymer derived from chitin. The control of their chemical and physical properties allows chitosan derivatives to be used for different biomedical and industrial applications.  On the other hand, Selenium is an essential trace element. In Nature, its main biological function is associated with the incorporation in the form of selenocysteine into certain proteins having redox motifs, such as Glutathione Peroxidase (GPx), among others. Different selenium containing compounds resulted to be bio-inspired catalysts, good antioxidant agents and good GPx-mimics. 
Our research focuses on the preparation of new selenoureidyl chitosan derivatives with tunable physicochemical properties by reaction of the biopolymer with a series of diversely substituted isoselenocyanates. This purpose will be carried out by taking advantage of the reactivity of chitosan´s amino group.
All new compounds have been characterized by NMR techniques both in solution and in solid state. To study the applicability of the new chitosan-derived selenoureas, antioxidant capacity and GPx-mimics ability have been investigated.
The authors thank the Junta de Andalucía (2011/FQM-142, and Project P09-AGR-4597); Spanish Ministerio de Economía, Industria y Competitividad (MINECO), Spain (CTQ2016-78703-P); A. J. Galera-Carrillo also thanks Universidad de Sevilla (PEJUS-2, 2017-2-EJ-070) for funding support. The authors also thank the CITIUS, Universidad de Sevilla, for the facilities.
- Prasanthi , N.L., Roy , H., Jyothi , N., Vajrapriya ,V.S. 2016 A Brief Review on Chitosan and Application in Biomedical Field American Journal of Pharmtech Research, 6, 41-51
- (a) Santi, C; Bagnoli. 2017 Celebrating Two Centuries of Research in Selenium Chemistry: State of the Art and New Prospective Molecules, 22, 2124. (b) Shchendrina, V.A.; Novoseleov, S.V.; Malinouski, M.Y.; Gladyshev, V.N. Identification and characterization of a selenoprotein family containing a diselenide bond in a redox motif Proc. Natl. Acad. Sci. 2007, 104, 13919-13924.