Stimuli‐responsive liposomes for drug delivery

<jats:p>The ultimate goal of drug delivery is to increase the bioavailability and reduce the toxic side effects of the active pharmaceutical ingredient (<jats:styled-content style="fixed-case">API</jats:styled-content>) by releasing them at a specific site of action. In the case of antitumor therapy, association of the therapeutic agent with a carrier system can minimize damage to healthy, nontarget tissues, while limit systemic release and promoting long circulation to enhance uptake at the cancerous site due to the enhanced permeation and retention effect (<jats:styled-content style="fixed-case">EPR</jats:styled-content>). Stimuli‐responsive systems have become a promising way to deliver and release payloads in a site‐selective manner. Potential carrier systems have been derived from a wide variety of materials, including inorganic nanoparticles, lipids, and polymers that have been imbued with stimuli‐sensitive properties to accomplish triggered release based on an environmental cue. The unique features in the tumor microenvironment can serve as an endogenous stimulus (<jats:styled-content style="fixed-case">pH</jats:styled-content>, redox potential, or unique enzymatic activity) or the locus of an applied external stimulus (heat or light) to trigger the controlled release of <jats:styled-content style="fixed-case">API</jats:styled-content>. In liposomal carrier systems triggered release is generally based on the principle of membrane destabilization from local defects within bilayer membranes to effect release of liposome‐entrapped drugs. This review focuses on the literature appearing between November 2008–February 2016 that reports new developments in stimuli‐sensitive liposomal drug delivery strategies using <jats:styled-content style="fixed-case">pH</jats:styled-content> change, enzyme transformation, redox reactions, and photochemical mechanisms of activation. <jats:italic>WIREs Nanomed Nanobiotechnol</jats:italic> 2017, 9:e1450. doi: 10.1002/wnan.1450</jats:p><jats:p>This article is categorized under: <jats:list list-type="explicit-label"> <jats:list-item><jats:p>Therapeutic Approaches and Drug Discovery > Emerging Technologies</jats:p></jats:list-item> <jats:list-item><jats:p>Biology-Inspired Nanomaterials > Lipid-Based Structures</jats:p></jats:list-item> <jats:list-item><jats:p>Nanotechnology Approaches to Biology > Nanoscale Systems in Biology</jats:p></jats:list-item> </jats:list></jats:p>