Administration-dependent efficacy of ferrociphenol lipid nanocapsules for the treatment of intracranial 9L rat gliosarcoma.

ABSTRACT

The anti-tumour effect of ferrociphenol (FcdiOH)-loaded lipid nanocapsules (LNCs), with or without a DSPE-mPEG2000 coating, was evaluated on an orthotopic gliosarcoma model after administration by convection-enhanced delivery (CED) technique or by intra-carotid injection. No toxicity was observed by MRI nor by MRS in healthy rats receiving a CED injection of FcdiOH-LNCs (60µL, 0.36mg of FcdiOH/rat) when the pH and osmolarity had been adjusted to physiological values prior to injection. At this dose, the treatment by CED with FcdiOH-LNCs significantly increased the survival time of tumour-bearing rats in comparison with an untreated group (28.5 days vs 25 days, P=0.0009) whereas DSPE-mPEG2000-FcdiOH-LNCs did not exhibit any efficacy with a median survival time of 24 days. After intra-carotid injection (400µL, 2.4mg of FcdiOH/rat), hyperosmolar DSPE-mPEG2000-FcdiOH-LNCs markedly increased the median survival time (up to 30 days, P=0.0008) as compared to the control (20%). This was strengthened by their evidenced accumulation in the tumour zone and by the measure of the fluorescent brain surface obtained on brain slides for these DiI-labelled LNCs, being 3-fold higher than for the control. These results demonstrated that, depending upon the administration route used, the characteristics of LNC suspensions had to be carefully adapted.