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.Innovations in stimuli-responsive surfaces, whose properties can be modified according to end-use application, have opened new doors for the design of drug-delivery systems (DDS). In this context, the layer-by-layer (LbL) method has attracted interest in the preparation of nano-sized DDS (NDDS) due to its low cost and ease of application to load individual or multiple drugs. In the last quarter, microcapsules and core-shell structures prepared by the LbL method, in multilayered form of highly charged particles (polyelectrolyte multilayers; PEMs), have been proposed as vehicles in NDDS. This review aims to provide an overview of LbL-PEMs in NDDS with an emphasis on emerging drug loading and releasing strategies in the last five years.