INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Polysaccharide-silica hybrids for cell encapsulation
Autor/es:
CARLA LLORENTE, MERCEDES PERULLINI, MATÍAS JOBBÁGY, ALBA MARCELLAN, DOMINIQUE HOURDET AND SARA A. BILMES
Lugar:
Madrid
Reunión:
Congreso; XVII International Sol-Gel Conference; 2013
Institución organizadora:
International Sol-Gel Society (ISGS) and the International Advisory Board (IAB)
Resumen:
Encapsulation of cells and microorganisms in silica based matrices give rise to new strategies for the design of materials with biological activity (MBAs) for a wide scope of applications, such as biosensors, bioreactors or bioremediation devices. Sol gel provides the basis for the synthesis of such matrices in a friendly environment for the encapsulated living species. However, the stress experienced by the cells during encapsulation, as well as the long term losses of water limits their survival. In this work we minimize the osmotic stress during encapsulation in sodium silicate based matrices by introducing a polysaccharide (PS) during the synthesis. The election of the biopolymer (Polyethylenglycol, PEG; Hyaluronic acid, HA) was based on the search of better ageing conditions in order to avoid fractures during syneresis by increasing the elasticity of the network. The synthesis parameters were adjusted in order to get a gelation time at pH = 6.0  0.1 in the 2-5 min range, which is appropriate for cell encapsulation. The Si content was fixed at 3.2 % Si (from Na silicate) and PS varied from 0 to 0.5% for HA and 0 to 30% for PEG. The hybrid material exhibits a complex microstructure from the analysis of scattering plots obtained from SAXS experiments. On the other hand, mechanical compression experiments indicate that the Young modulus increases and hybrid hydrogels exhibit better resistance to fracture. The viability of E. Coli in the hybrid gels is also improved with PS. More remarkable effects are found when HA is employed in the co-polymerization with silica, even the lower mass content due to the longer chains with undergo to physical cross linking before gelation of silicate