Layer-by-layer assembly for drug delivery and related applications

Introduction: High-performance drug delivery systems are always made through assembly and hybridization of multiple components, each of which possesses its own role within the unified delivery function. The layer-by-layer (LbL) adsorption technique offers huge freedom in material selection and flexibility of structural design, which are fully matched with the fabrication needs of drug delivery materials requiring complicated designs. Areas covered: In this review, film-type LbL assemblies and their drug delivery application are focused on, with selected examples from recent years. In addition to a description of the general progress of this technique in bio-related areas, examples of the delivery of low-molecular-mass drugs, DNA, peptides and proteins are summarized, as well as recent advances in film structures composed of organic/inorganic hybrids. Expert opinion: The authors expect that the highly versatile nature of the LbL assembly can overcome any remaining practical difficulties in delivering therapeutics, because the layer structure, component selection, and the surface nature including biocompatibility, degradability and size/dimension are all adjustable. Furthermore, the simple and inexpensive nature of this technique can also satisfy strict demands from an economic point of view.