Simplifying Molecular Transport in Polyelectrolyte Multilayer Thin Films

The matrix properties of polyelectrolyte multilayer thin films (PEM) are critical in making them a viable candidate for various biomedical applications. The location and ability of molecules to diffuse through the PEM architecture determines their encapsulation and release capabilities in a given matrix for various biomedical applications. The main aim of this review article is to provide a complete understanding of molecular transport on the surface as well as across the bulk of the PEM matrix. Different physiochemical strategies to promote or suppress the diffusivity of various molecules inside the PEM are mentioned in brief. A set of guiding principles is uncovered for getting a complete picture of loading and release of molecules across the PEM structure, which can play a key role in designing a desirable PEM assembly and have important implications for designing multicomponent, targeted and controlled drug-delivery vehicles. Understanding the molecular diffusivity in PEM stack at the nano and micro scales will help to design superior host materials for biomedical engineering applications.