INQUIMAE   12526
Unidad Ejecutora - UE
congresos y reuniones científicas
Nanostructured oxides with biological activity
Workshop; workshop on oxide materials: novel multifunctional properties; 2014
Nanostructured oxides with biological activity Sara A. Bilmes Universidad de Buenos Aires, Facultad Ciencias Exactas y Naturales, Instituto de Química Física de los Materiales, Medio Ambiente y Energía ? INQUIMAE- DQIAQF, Ciudad Universitaria Pab II, Ciudad Autónoma de Buenos Aires, C1428EHA, Argentina Encapsulation of cells in mineral matrices allow the design of materials with biological activity (MBAs) that can work for long times if they are put in contact with appropriate nutrients in a physical space allowing cellular division. The main advantage of these matrices is that they are not easily biodegradable, and the control of porosity and mechanical performance provides a scaffold for the design of new MBAs that can be used in natural systems without being predated nor released to the environment. Around 200 1012 moles of Si are processed in a year by diatoms in the oceans. From these living organisms producing hierarchical nanostructured silica we learned that life is possible within silica ?cages? and silica structures can be built at room temperature by a sol-gel process. However, even the mild conditions in ?chimie douce? the extension of this concept for encapsulating cells and microorganisms in the lab is a real challenge as the concentrations of precursors usually exceeds the toxicity limits accepted by living species. In this talk different strategies developed in our group for encapsulating different living organisms - i.e. algae, fungi, bacteria, plants - are presented. These were planned in order to protect the biological species against the toxicity of reagents, as well as osmotic stress induced at high ionic strength. Even most of the work has been carried out with silica or silica-biopolymer hybrids using silicate, silica nanoparticles or silica alkoxydes as precursors, we explored other oxides, such as zirconia and alumina whose precursors exhibit more detrimental effects. These can be managed in conditions in which the cells are protected. These new biomimetic materials based on oxides open the possibility of designing sensors, bio-reactors and bio-remediation devices.