20.07.2022: Publication Alert - Evaluation of Polyoxazolines Insertion into the Epidermis: From Membrane Models to in Vivo Studies
The aim of our study was to evaluate the interaction of amphiphilic POx with different biological membrane models of increased complexity: simple lipid bilayers, cell membranes and murine skin. Overall, POx proved to be an excellent choice for topical delivery, which might offer novel possibilities for skin treatments in different diseases, such as psoriasis or melanomas.
In this study, we evaluated the potential of amphiphilic polyoxazolines (POx) to interact with biological membranes thanks to models of increasing complexity, from a simple lipid bilayer using giant unilamellar vesicles (GUV), to plasma membranes of three different cell types, fibroblasts, keratinocytes and melanocytes, which are found in human skin. Upon assessing an excellent penetration into GUV membranes and cultured cells, we addressed POx’s potential to penetrate the murine skin within an in vivo model. Exposure studies were made with native POx and with POx encapsulated within lipid nanocapsules (LNC). Our findings indicate that POx’s interactions with membranes tightly depend on the nature of the alkyl chain constituting the POx. Saturated C 16 POx insert rapidly and efficiently into GUV and plasma membranes, while unsaturated C 18:2 POx insert to a smaller extent. The high amount of membrane-inserted saturated C 16 POx impacts cell viability to a greater extent than the unsaturated C 18:2 POx. The in vivo study, performed on mice, showed an efficient accumulation of both POx types in the stratum corneum barrier, reaching the upper epidermis, independently of POx’s degree of saturation. Furthermore, the formulation of POx into lipid nanocapsules allowed delivering an encapsulated molecule, the quercetin, in the upper epidermis layers of murine skin, proving POx’s efficacy for topical delivery of active molecules. Overall, POx proved to be an excellent choice for topical delivery, which might in turn offer new possibilities for skin treatments in diseases such as psoriasis or melanomas.