The interaction of cationic dendrons with albumin and their diffusion through cellulose membranes

Amphipathic dendrons (partial dendrimers) having three lipidic (C-14) chains coupled to dendritic lysine head groups with 8, 16 or 32 free terminal amino groups have been synthesised by solid phase peptide synthesis. Their interaction with albumin was studied in the presence of NaCl using dynamic dialysis, the diffusion of the dendrons through regenerated cellulose membranes also being studied. The stoichiometry of dendron: albumin interactions was found to be 1:1.5, 1:4 and 1:5 for the dendrons with 8, 16 and 32 amino groups, respectively. Membrane permeability P, membrane diffusion coefficient D and the membrane partition coefficient K values were calculated for each dendron. P and D values were low but highest for the 8 amino group dendron. The membrane partition coefficient K was greatest for the 8 amino group dendron. This was also the case with octanol/water partition coefficient studies. Considerable adsorption of the dendrons to the cellulose membrane occurred but NaCl decreased adsorption and improved diffusion of the dendrons through the cellulose membrane. (C) 2002 Elsevier Science B.V. All rights reserved.