Free peptide was removed from the liposome formulation by gel filtration using a Sephadex G50 filled column. 750 μL of the liposome suspension was transferred to the column. Once fully permeated into the column 200 μL of 20 mM Tris buffer (pH 7.4) was added. Next, fractions were collected by sequential addition of 750 μL of buffer. The liposomes eluted in fractions 4-6. After collection of the liposomes, 8 mL of buffer was flown through the column to remove free peptide (Supporting Information, Section S1).