Inducing Controlled Release and Increased Tumor-Targeted Delivery of Chlorambucil via Albumin/Liposome Hybrid Nanoparticles.

Liposomes possess good biocompatibility and excellent tumor-targeting capacity. However, the rapid premature release of lipophilic drugs from the lipid bilayer of liposomes has negative effect on the tumor-targeted drug delivery of liposomes. In this study, a lipophilic antitumor drug-chlorambucil (CHL)-was encapsulated into the aqueous interior of liposomes with the aid of albumin to obtain the CHL-loaded liposomes/albumin hybrid nanoparticles (CHL-Hybrids). The in vitro accumulative release rate of CHL from CHL-Hybrids was less than 50% within 48 h, while the accumulative CHL release was more than 80% for CHL-loaded liposomes (CHL-Lip). After intravenous injection into rats, the half-life (t _1/2β  = 5.68 h) and maximum blood concentration (C _max  = 4.58 μg/mL) of CHL-Hybrids were respectively 1.1 times and 3.5 times higher than that of CHL-Lip. In addition, CHL-Hybrids had better tumor-targeting capacity for it significantly increased the drug accumulation in B16F10 tumors, which contributed to the significantly control of tumor growth compared with CHL-Lip. Furthermore, CHL-Hybrid-treated B16F10 melanoma-bearing mice displayed the longest median survival time of 30.0 days among all the treated groups. Our results illustrated that the proposed hybrids drug delivery system would be a promising strategy to maintain the controlled release of lipophilic antitumor drugs from liposomes and simultaneously facilitate the tumor-targeted drug delivery.