Chapter 1.4 - Layer-by-Layer Assembly for Nanoarchitectonics

Abstract

Nanoarchitectonics is a new term that has been proposed in the nanotechnology field to define a technology based on the arrangement of nanoscale units as a whole, which enables the structuring of functional nanomaterials. Different interactions of the single components allow the fabrication of structures with different functionalities, and, therefore, the layer-by-layer (LbL) assembly technique is linked with the nanoarchitectonics concept. The LbL technique is based on the deposition of two (or more) spontaneous interacting components, generally polyelectrolytes with opposite charges. The number of polyelectrolyte layers, the deposition technology, the nature of the interactions between the components and the chosen components, as well as the produced systems, make LbL a versatile technique. For that reason, throughout the past decades, the LbL assembly technique has elicited the interest of the research community. Recently, the application of the LbL towards innovative assemblies has evolved exponentially. The application of LbL in the production of drug delivery systems, mainly by the deposition of the commonly used bilayer pair of poly(allylamine hydrochloride) (PAH) and poly(sodium styrenesulfonate) (PSS), confers protection to the molecule of interest, increases the circulation durability, and enables a targeted and controlled release. In this chapter, a comprehensive review of the literature regarding LbL assembly technique is presented, highlighting the particularities of the use of LbL in the fabrication of hollow capsules, gelatin nanostructures, and coated drug-core nanoparticles. Among those, the cell coating topic is emphasized as a recent line of research that combines the LbL technique and the deposition of nanomaterials in the surface of biological cells, giving rise to upgraded cells with a wide spectrum of promising applications.