Nanoliposomes in skincare products http://creativecommons.org/licenses/by-nc-sa/4.0/legalcode Skin is the largest human organ, and topical formulations have been applied to the skin for centuries for cosmetic and therapeutic purposes. Topical formulations active ingredients can be easily administered with a minimal invasion, leading to an increased compliance. Advanced topical formulations have been developed to stabilize active molecules, but mostly for increasing the depth of penetration within the skin. The skin acts as an extraordinary barrier for actives’ delivery (Dragicevic & Maibach, 2024). The outermost skin layer, the stratum corneum (SC), is the major permeation obstacle for most molecules, especially for hydrophilic ones, due to SC structure that has been described as a “brick and mortar model,” representing the corneocytes and the surrounding intercellular lipids (El Maghraby et al., 2008). Liposomes were the first lipid vesicles introduced by Bangham and Horne in 1964 (Bangham & Horne, 1964) considered for drug delivery. These vesicles have been used as models of biological membranes and, later, as carriers of bioactive agents in different areas such as therapeutics, cosmetics, vaccines, tissue engineering, imaging, and food technology (Akbarzadeh et al., 2013). Several generations of liposomes can be considered. The designation of nanoliposome became popular; however, it contains a redundancy, as liposomes are, by definition, nanostructured vesicular systems. In this work, the term nanoliposomes will be used for describing the different types of phospholipid nanosized vesicles or liposome-like structures composed of at least one bilayer that encloses a number of spherical aqueous compartments. For therapeutic purposes, liposomes have evolved strategies to escape from capture by the mononuclear phagocytic system (MPS) upon parenteral administration or to the vectorization for cellular or extracellular compartments. In parallel, for skin care, the strategy followed the incorporation of molecules able to destabilize the lipid bilayer to modify the deformability of the vesicles and change the vesicles interaction with the skin. Conventional liposomes are nondeformable structures, and once applied to the skin, they fuse and create an occlusive layer, increasing skin hydration and promoting the permeation of active molecules. In 1992, a new type of vesicle called elastic or (ultra)deformable liposomes/vesicles was developed where the lipid bilayer can be doped with a surfactant or an edge activator (Cevc & Blume, 1992) that destabilizes the vesicle, making it deformable. After that, many other deformable vesicles have been proposed. Some of these technological approaches have reached the cosmetic market, and many active molecules have been studied to be transported to the skin by means of such modified liposomes. info:eu-repo/semantics/bookPart https://phaidrabg.bg.ac.rs/o:36962 doi: https://doi.org/10.1016/B978-0-443-30184-1.00022-3 ISBN: 978-0-443-30184-1 eng 2025 application/pdf 774632 bytes Simões, Sandra Jovanović, Aleksandra Ali, Nsrein Ribeiro, Ana Pereira-Leite, Catarina Aruci, Edlira Colley, Helen Lima, Sofia Nanoliposomes in skincare products startpage: 263 endpage: 278 Academic Press is an imprint of Elsevier