Gold nanoparticle loaded phytosomal systems: synthesis, characterization and in vitro investigations

Most medicinal and pharmaceutical herbal extracts are poorly soluble in aqueous moieties and have reduced adsorption by living cells. Liposomal encapsulation of those so called phytosomes could be a solution to overcome this problem. Meanwhile, much research shows that metallic nanoparticles such as gold nanoparticles ( AuNPs) exhibit biological activity such as wound healing and antioxidant properties on living cells. Here, we constructed a novel liposomal formulation by encapsulating both Calendula officinalis extract and AuNPs. After the preparation of vesicles using the traditional thin film hydration method within extrusion, the resulting AuNP-phytosomes were characterized by dynamic light scattering size measurements, zeta potential and atomic force microscopy. These vesicles are less than 100 nm in size and have a high encapsulation efficiency for chlorogenic acid and quercetin as the model major molecules of Calendula extract. Furthermore, AuNP-phytosomes exhibited antioxidant and wound healing activity significantly according to the free forms of each encapsulated material and the plain liposome as well as the phytosome form. Moreover, the cellular interactions of the vesicles were monitored using the nano-vesicles prepared by Texas-Red labelled lipids under fluorescence microscopy.