In vitro and in vivo anti-tumor effects of gemcitabine loaded with a new drug delivery system.

: In recent years, much attention has been given to liposomal formulation as an efficient drug loading system (DDS) in chemotherapy of cancer. In this study, the advantages of magnetic nanoparticles and Polyethylene Glyco (PEG) materials were considered to synthesize magnetic gemcitabine long-circulating liposomes (MGLL) and the potential of MGLL as a brand new delivery system was evaluated. MGLL was prepared using the reverse-phase evaporation method. In the optimized preparation, MGLL had an average diameter of 201 nm with a narrow size distribution measured by dynamic light scattering (DLS), which could be easily dispersed in ultrapure water under a stable state for 90 days. The encapsulation efficiency of gemcitabine in MGLL reached 87.2% as determined by HPLC. In vitro MTT assay showed that MGLL had significant cytotoxicity to MCF-7 cells compared with the conventional modalities. In vivo, the inhibition of tumor growth in MGLL group was more remarkable than that of other groups (P < 0.05). In conclusion, MGLL under optimized condition could be used as an effective carrier for tumor-targeted therapy.