In vitro binding of HSA, IgG and HDL on liposomes of different compositionand its correlation with the BLOOD/RES ratio of liposomes

The in vitro binding of the serum proteins human serum albumin (HSA), human serum immunoglobulin (IgG) or human serum high density lipoprotein (HDL) o n unilamellar liposomes of different lipid composition was studied. HDL bou nd on liposomes at higher amounts than IgG and IgG at higher amounts than H SA. The protein binding on liposomes decreased when bovine brain monosialga nglioside (GM(1)) or poly(ethyleneglycol)-distearoylphosphatidylethanolamin e (DSPE-PEG) was included in liposome membrane. With all three proteins, an inverse relationship was found between the amount of protein bound on lipo somes after 1 h liposome-protein incubation in vitro and the BLOOD/RES rati o of the same liposomes 2 min after i.v. administration in mice (Panagi et al., Drug Dev. Ind. Pharm., 22 (1996) 217-224). The potential value of this in vitro-in vivo correlation, provided it is extended to additional liposo me compositions, is that it may provide an in vitro method to screen liposo mes in terms of blood clearance rates. (C) 1999 Elsevier Science B.V. All r ights reserved.