Anti-metastatic activity of MDP-L-alanyl-cholesterol incorporated into various types of nanocapsules.

A lipophilic immunomodulator (MTP-Chol) was included in nanocapsules prepared from different polymers and the anti-metastatic effects of the resulting drug delivery systems were evaluated in a murine model of liver metastases. Loaded nanocapsules were effective if they were given 2 days before tumor inoculation. Neither the nature of the polymer nor the total dose of immunomodulator affected the antimetastatic capacity. However, enhanced anti-metastatic activity was obtained when indomethacin nanocapsules were associated with MTP-Chol nanocapsules. These results show that nanocapsules containing an immunomodulator possess anti-metastatic activity, but only when given as a prophylactic treatment; this would correspond, in the clinic, to patients undergoing surgery for a primary tumor and at risk of developing liver metastases.