The skin plays an important role as a protective barrier against toxic environments and also is a route of drug administration. The skin represents the main interface between our organs and the external environment. Through the skin we release biological fluids (like sweat, sebum) full of analytes and hormones, useful biomarkers to test our healthy or pathological status. Moreover the cutaneous treatment still represents the most investigated way between available administration routes for local and systemic diseases.
For this purpose we study the transdermal transport phenomena of different molecules, nanoparticles and drugs both from epidermis to dermis and dermis to epidermis by means of Franz-type diffusion cell.
In particular in the last year we are focusing on some nanoparticles (NPs) as promising candidate for a transdermal drug delivery system. In collaboration with University of Milano-Bicocca (UNIMIB) we performed several experiments using colloidal iron oxide NPs in two different formulations. Our specific goal is to evaluate NPs permeability through the human skin. Franz diffusion cell system is employed to show the NPs penetration through all layers of human skin, then the samples are studied by ultrastructural analysis (SEM and TEM). The preliminary results indicated a successful NPs penetration up to dermis, as observed in the microphotographs performed in UNIMIB (see the images below)A: Experimental set up of Franz-type diffusion cell with ex-vivo human skin and Nps formulation in the donor chamber.
B and C: Ultrasctructural analysis of Nps penetration in the dermis, the black arrows indicates the Nps penetrated (B: SEM analysis, C: TEM analysis)