Binding of liposomes to human bladder tumor epithelial cell lines: implications for an intravesical drug delivery system for the treatment of bladder cancer.

Present therapy of human superficial bladder cancer includes the intravesical administration of antitumor drugs and immunomodulators. The purpose of these studies was to determine whether liposomes can bind to human bladder cancer cells and thereby provide a mechanism to improve the delivery of anticancer agents to diseased urothelium. Negatively charged large multilamellar vesicles (MLVs) bound to four different human bladder tumor cell lines (253J, J82, T24, TCCSUP) more avidly than did small sonicated vesicles or vesicles consisting of uncharged phosphatidylcholine (PC). Of the three types of negatively charged MLVs tested, phosphatidylcholine/phosphatidylserine (7:3, mol ratio) (PC/PS) MLVs bound the most. MLV binding to tumor cells was saturable and appeared to be specific. In contrast, the binding of liposomes to normal fetal bladder cells was minimal. These data suggest that targeting of drugs to superficial bladder cancer can be achieved by the intravesical administration of PC/PS MLV.