Characterization of Mixed Langmuir Monolayers of Cyclosporine a With the Phospholipid DPPC at the Chitosan Subphase

Abstract

The properties of one-component and mixed monolayers of phospholipid 1,2–dipalmitoyl–sn–glycero–3–phosphocholine (DPPC) and polypeptide cyclosporine A (CsA) on the chitosan subphase were studied. DPPC is the main component that builds biological membranes, and CsA is an immunosuppressive drug typically used in medicine to prevent transplant rejections. The stability and reversibility of compression of these insoluble monolayers in the presence of chitosan (Ch) were examined by the Langmuir technique. The stability of the monolayers depended on the monolayer composition as well as the initial pressure (π0) of the relaxation process. The smallest changes in the relative pressure as a function of time were obtained at π0 = 10 mN/m. During compression–decompression cycles, the effect of chitosan was noticeable and caused isotherm shifts.