Magnetic poly epsilon-caprolactone nanoparticles containing Fe3O4 and gemcitabine enhance anti-tumor effect in pancreatic cancer xenograft mouse model.

We prepared magnetic (Fe(3)O(4)) poly epsilon-caprolactone (PCL) nanoparticles (mean diameter 164 +/- 3 nm) containing an anticancer drug (gemcitabine) using emulsion-diffusion method in order to develop more efficient drug delivery for cancer treatment. Nanoparticles were smooth, well individualized and homogeneous in size. The values of magnetizations for the magnetic PCL nanoparticles were observed around 10.2 emu/g at 2000 Oe magnetic field intensity and showed super-paramagnetic property. In case of the drug, the drug loading contents was 18.6% and entrapment efficiency was 52.2%. The anti-tumor effects caused by these particles were examined using nude mice bearing subcutaneous human pancreatic adenocarcinoma cells (HPAC) in vivo. We divided that these mice were randomly assigned to one of five treatment groups for experimental contrast. The antitumor effect was showed with 15-fold higher dose when compared to free gemcitabine. From the result, the magnetic PCL nanoparticles may provide a therapeutic benefit by delivering drugs efficiently to magnetically targeted tumor tissues, thus achieving safe and successful anti-tumor effects with low toxicity.

Retargeting of adenoviral gene delivery via Herceptin-PEG-adenovirus conjugates to breast cancer cells.

Targeted adenoviral gene delivery using human epidermal growth factor receptor 2 (HER2/neu) is one of the promising strategies for enhancing the transduction efficacy of PEGylated adenovirus (PEG-ADV). The viral capsid of adenovirus carrying the green fluorescent protein (GFP) was conjugated with bifunctional polyethylene glycol (PEG). The surface of PEG-ADV was then further conjugated with anti-HER2/neu monoclonal antibody (MAb), Herceptin (Trastuzumab; HER) to grant HER2/neu over-expressed breast cancer cells specific targeting. The PEG-ADV and Herceptin immobilized PEG-ADV (HER-PEG-ADV) extents of retargeting were evaluated, as compared to those of naked ADV. In summary, HER-PEG-ADV exhibited more enhanced level of GFP expression than PEG-ADV did for MDA-MB-435 and MDA-MB-468 cells (a HER2/neu positive cell line), but not for a HER2/neu deficient U251N cells. PEGylated ADV significantly reduced innate immune response likewise, as judged from the amount of interleukin 6 released from macrophage cells. Consequently, this study suggests that HER-PEG-ADV conjugates enable ADV to become more potential therapeutic tools through overcoming the limitation of ADV against immune system and non-specificity.