Layer by layer self assembly of Polyelectrolytes and S-layers

Layers represent the outermost cell envelope component of many prokaryotic organisms. Isolated S-layer subunits have the capability to assemble into monomolecular arrays. Combination of S-layer self assembled proteins with Polyelectrolyte (PE) multilayers and PE capsule (S-Capsules) gives the possibility to functionalize the surface of the capsules. The properties and the composition of PE plays an important role in the crystallization pattern of S-layers and subsequently in immobilization of macromolecules. In this work the layer by layer self assembly of polyelectrolytes and S-layers was monitored and the resulting assemblies used to fabricate S-Capsules. Results showed S-layers were absorbed on both positive and negative planar polyelectrolyte films. 200 ng of S-layer was deposited on PSS which corresponds to a layer with a thickness of 4 nm. After 1 hour the amount of S-layer deposited on PSS and PAH was 470 and 490 ng respectively. The layer thickness was found to be 8 and 9 nm. The crystallization of S-layer was also carried successfully on polyelectrolyte capsules with PSS as the final layer. The S-capsules are suitable tool for technological application and drug delivery purposes.