Cytotoxicity of doxorubicin-loaded Con A-liposomes

The present study investigated the potential of Concanavalin A lectin (Con A) conjugated to liposomes (Con A‐liposomes) for targeting doxorubicin (DOX) to cells. The physicochemical properties and the cytotoxicity of DOX‐loaded Con A‐liposomes were evaluated. DOX‐loaded Con A‐liposomes were prepared by incubation of DOX‐loaded liposomes with a Con A‐SATA derivative. Lectin biological activity was monitored before and after conjugation by a hemagglutinating assay. The cytotoxicity of DOX‐loaded Con A‐liposomes was evaluated in terms of the inhibition of NCI‐H299 and HEp‐2 cell proliferation using the MTT method. The affinity of lectinized liposomes with these cells was thus assessed by evaluating the cytotoxic effect of the DOX released into cells. Stable DOX‐loaded Con A‐liposomes were obtained and their high affinity for cells was corroborated. The encapsulation of DOX into Con A‐liposomes produced an inhibition of roughly 70% of Hep‐2 cell proliferation and 50% of cell inhibition was verified on HCI‐H292. DOX in solution was able to inhibit only 20% of cell proliferation for both cell lines. Unloaded Con A‐liposomes were not cytotoxic. The encapsulation of DOX into Con A‐liposomes improves drug penetration into cells, thereby enhancing its cytotoxicity, especially in Hep‐2 cells. Drug Dev. Res. 67:430–437, 2006. © 2006 Wiley‐Liss, Inc.