Rational design of a nonclassical liposomal nanoscale drug delivery system for innovative cancer therapy

Advanced drug delivery systems are widely considered to be powerful approaches for treating cancer and many other diseases because of their superior ability to improve pharmacokinetics, promote lesion-targeted delivery efficacy, and/or reduce the toxic effects of diverse therapeutics. Owing to the unique biomimetic structure of lipid bilayers surrounding aqueous cavities, liposomes have been found to encapsulate various therapeutics, ranging from small molecules with different hydrophobicities to biomacromolecules. With the advent of surface PEGylation, stealth liposomes with excellent in vivo long-circulating behaviors have been generated, thus these liposomes have been extensively explored for the development of liposomal drugs with greatly improved in vivo pharmacokinetic behaviors by functioning as delivery vehicles. Inspired by their successes in clinical practice, stealth liposomes have recently been utilized as the main building scaffold or surface coating layers of other nanoparticulate formulations, which are coined as nonclassical liposomal nanoscale drug delivery systems (NDDSs) in this review, to enable the rational design of next-generation liposomal nanomedicine. Therefore, after overviewing the latest progress in the development of conventional liposome-based nanomedicine, we will introduce the development of these nonclassical liposomal NDDSs as well as their innovative cancer treatment strategies. We will subsequently provide a critical perspective on the future development of new cancer nanomedicines based on these rationally designed nonclassical liposomal NDDSs.