Topical anti-inflammatory potential of quercetin in lipid-based nanosystems: In vivo and in vitro evaluation
Purpose: To develop quercetin-loaded phospholipid vesicles, namely liposomes and PEVs (Penetration Enhancer-containing Vesicles), and to investigate their efficacy on TPA-induced skin inflammation. Methods: Vesicles were made from a mixture of phospholipids, quercetin and polyethylene glycol 400 (PEG), specifically added to increase drug solubility and penetration through the skin. Vesicle morphology and self-assembly were probed by Cryo-Transmission Electron Microscopy and Small/Wide Angle X-ray Scattering, as well as the main physico-chemical features by Light Scattering. The anti-inflammatory efficacy of quercetin nanovesicles was assessed in vivo on TPA-treated mice dorsal skin by the determination of two biomarkers: oedema formation and myeloperoxidase activity. The uptake of vesicles by 3T3 fibroblasts was also evaluated. Results: Small spherical vesicles were produced. Their size and lamellarity was strongly influenced by the PEG content (0%, 5%, 10% v/v). The administration of vesicular quercetin on TPA-inflamed skin resulted in an amelioration of the tissue damage, with a noticeable attenuation of oedema and leukocyte infiltration, especially using 5% PEG-PEVs, as also confirmed by confocal microscopy. In vitro studies disclosed a massive uptake and diffusion of PEVs in dermal fibroblasts. Conclusions: The proposed approach based on quercetin vesicular formulations may be of value in the treatment of inflammatory skin disorders. ; This study was supported by a grant from the University of Valencia (Relacions Internacionals I Cooperació), a grant from MIUR, Italy (PRIN 2010-2011, Prot. 2010H834LS_004), a grant from the Ministerio de Ciencia e Innovación, Spain (BIO2011-25039), which included FEDER funds, and by a grant from the Generalitat de Catalunya, Spain (2009SGR-760). Dr. C. Caddeo gratefully acknowledges Sardinia Regional Government for the financial support (P.O.R. Sardegna F.S.E. Operational Programme of the Autonomous Region of Sardinia, European Social Fund 2007-2013 - Axis IV Human Resources, Objective l.3, Line of Activity l.3.1 "Avviso di chiamata per il finanziamento di Assegni di Ricerca". ; Peer reviewed