Protection of skin and treatment of lesions using phospholipid vesicles tailored for the topical delivery of phytochemicals from Sardinian flora

Natural bioactives, especially those derived from plants, have gained a great popularity throughout the scientific community and among the final users, as they are considered an ideal alternative to synthetic drugs to prevent chronic diseases and treat minor affections, especially at skin level. To substantiate their activities, different plant-derived molecules and extracts have been tested, mainly in vitro. In addition, in the last decades, several studies have been centred on their incorporation into innovative and effective nanocarriers aiming at improving their beneficial properties upon application on the skin. Among the proposed nanocarriers, phospholipid vesicles appeared to be the most effective thanks to their ability to interact with the skin components and reach the deeper strata, along with their high biocompatibility and feasibility. To exploit phytochemicals obtained from the Sardinian flora to prepare natural and environmentally-friendly formulations based on phospholipid vesicles specifically tailored for the treatment of skin damages and lesions. An extract of Hypericum scruglii, an endangered endemic plant of Sardinia (Italy), was prepared and characterized. It was loaded in special phospholipid vesicles, glycerosomes, which were modified by adding maltodextrin (glucidex) and a polymer (gelatin or hyaluronan). The vesicle dispersions maintained unchanged characteristics during 60 days of storage, were highly biocompatible, and were able to protect keratinocytes against damages due to oxidative stress induced by treating them with hydrogen peroxide. Vesicles were also capable of promoting cell proliferation and migration in vitro by means of a scratch wound assay. The results confirmed the fruitful delivery of the extract of H. scruglii in glycerosomes modified with glucidex and gelatin and their promising ability for skin protection and treatment. Collagen-enriched transfersomes, glycerosomes, glytransfersomes were specifically tailored for skin delivery of oleuropein. Vesicles were prepared by direct sonication and their main physico-chemical and technological properties were measured. Biocompatibility, protective effect and promotion of the healing of a wounded cell monolayer were tested in vitro using fibroblasts.Collagen-enriched vesicles seemed to be promising formulations capable of speeding-up the healing of the wounded skin. Pistacia lentiscus L. is a sclerophyllous shrub capable of growing under harsh climatic conditions especially in the Mediterranean Basin. Different products can be obtained from this plant, such as essential oil, mastic gum or even fixed oil. In this study, the lentisk oil has been incorporated into liposomes prepared with natural soy lecithin, using a green and organic solvent free method, thus obtaining spherical, small (~ 118 nm), homogeneously dispersed (0.27) and highly negatively charged (~ -62 mV) vesicles. Overall findings suggested that the incorporation of lentisk oil in liposomes made from soy lecithin can be an alternative and natural approach suitable for the treatment of skin wounds specifically connected with oxidative stress.