Layer-by-layer self-assembled emerging systems for nanosized drug delivery

New frontiers in the development of stimuli-responsive surfaces that offer switchable properties according to the end-use application have added a new dimension to the design of drug-delivery systems (DDS). In this respect, layer-by-layer (LbL) self-assembled technologies have attracted interest in nano-DDS (NDDS) design due to the advantage of encapsulating different drug types either individually or in multiple formulations as an easy-to-apply and cost-effective strategy. LbL-based microcapsules and core-shell structures in the form of polyelectrolyte multilayers (PEMs) have been proposed as versatile vehicles for NDDS over the last quarter. This review aims to provide a global view of LbL-PEMs used as templates in NDDS for the last 5 years with an emphasis on emerging drug loading and release strategies.