Increased stability in plasma and enhanced cellular uptake of thermally denatured albumin-coated liposomes

Liposomes are nano-scale vesicles that can be used as one of drug carriers. The liposomes are, however, plagued by rapid opsonization of them and hence making their circulation time in bloodstream to be shortened. In this study, cationically charged liposomes of which surface was modified with bovine serum albumin (BSA) were prepared by using electrostatic interaction between cationic liposomes and anionically charged BSA molecules at higher pH than isoelectric point (pI) of BSA. The BSA-coated liposomes (BLs) were denatured by thermal treatment of BL at 100 °C. The thermally denatured BSA-coated liposomes (DBLs) have mean particle diameter of 109 ± 1 nm. Encapsulation of model drug, doxorubicin (DOX), in the liposomes was carried out by using, so called, remote loading method and loading efficiency of DOX in liposomes was about 90%. DBL800 showed higher stability in plasma compared to Doxil^®. Results of intracellular uptake evaluated by flow cytometry and confocal microscopy studies showed higher intracellular uptake of DBL800 than that of Doxil^®. Consequently, the DBL, of which surface was complexed with denatured protein may be applicable as drug delivery carriers for increasing stability in plasma and enhanced cellular uptake efficacy of anticancer drugs.