Protection capability of polyelectrolyte

The development of an encapsulation method for biologi- cal cells endowed of sufficient permeability that oxygen and nutrients can feed the cells, and appropriate cellular products can be released in a programmed way, can open new avenues in the realization of artificial cellular networks and smart bio- sensors [1]. The capsular material should be restrictive enough to prevent encapsulated cells from the attack of specific pro- teins and enzymes filtered by the permeability properties of the capsule itself. A suitable system to this end can be designed and realized using charged polyelectrolytes assembled by means of the Layer-by-Layertechnique [2, 3]. In the present work we assess the ability of polyelectrolyte nanostructured shells to protect Saccharomyces cerevisae yeast cells inserted within a heterologous organism, the protozoan Paramecium primaurelia, against lysosomial enzymes attack. To investigate the influence of preparation conditions we used PE solutions at three different ionic strengths. This allowed to stress the role of salt concentration on the properties of the multilayer shell. As well, we modulated the number of layers of the shell in order to derive those conditions enabling protection of the cells from digestion by Paramecium's lysosomal enzymes. Yeast cells via- bility was tested by observing population growth dynamics. This study has been carried out by means of confocal laser scanning microscopy and fluorescence labelling [4]. Results about optimal conditions for the protection of the yeast against destruction by lytic enzymes are reported