European Journal of Cardio-Thoracic Surgery, Vol 10, 574-578, Copyright © 1996 by European Association for Cardio-thoracic Surgery
Potentials of liposomes in diagnosis and treatment of pulmonary metastases: an experimental study in the rat
L Roveda, U Prati, L Diomede, M Salmona, G Bottiroli, N Scoppetta and S Nazari
Department of Surgery, IRCCS Pol. S. Matteo, Pavia, Italy.
OBJECTIVE: The ultimate goal of the therapy of lung metastases is to
destroy all malignant cells while sparing normal ones. Liposomes represent
a novel approach for the selective transport of tracers and therapeutic
agents to cancer cells because of their flexibility, low toxicity, wide
range of possible variants, simplicity to make, and because agents can be
entrapped in them in their native states in large amounts. We have studied
the biodistribution of "Stealth" liposomes in the experimental model of
lung metastases in the rat. METHODS: The secondaries were induced by i.v.
injection 20. 10(6) cancer cells (DHD/K12/TRb line) in BD-IX rats. The
study of the liposome biodistribution in the rat was carried out by the use
of unilamellar liposomes with homogeneous size distribution (0.1 microns),
the liposomes were labeled with Cholesteryl-Bodipy. The rats were
sacrificed at scheduled times after the injection; blood, urine, metastatic
and healthy lung, colon, liver and spleen were analysed by a
microcytofluorimetric examination. RESULTS: Liposomes prolonged the
circulation time of Cholesteryl-Bodipy. Only spleen and lung metastases
exhibited an accretion of fluorescent liposomes. CONCLUSIONS: The
biodistribution of such formulation of liposomes in rats with lung
metastases, may be of considerable importance in diagnosis and therapy of
the secondaries, for increasing the concentration of tracers and
therapeutic agents in tumor tissue while minimizing the likelihood of
aspecific distribution and toxicity to non target tissue.
