RESUMO
PURPOSE: Pancreatic cancer is the fourth most common cause of cancer-related death in the USA. This is mainly because of the chemoresistance of this type of tumor; thus, the development of novel therapeutic modalities is needed. METHODS: Long-circulating and pH-sensitive liposomes containing cisplatin (SpHL-CDDP) were administered systemically into pancreatic tumor-bearing mice for a period of 14 days. The antitumor efficacy and toxicity of this new treatment method on the basis of cisplatin-loaded liposomes was compared with the classical free-CDDP method. Tc-HYNIC-ßAla-bombesin(7-14) tumor uptake and histopathologic findings were used to monitor and compare the two treatment modalities. RESULTS: The antitumor activity of SpHL-CDDP treatment was shown by (a) decrease in tumor volume, (b) development of tumor necrotic areas, and (c) decrease in Tc-HYNIC-ßAla-bombesin(7-14) tumor uptake. Toxicity was evaluated by the development of inflammation and necrotic areas in the kidneys, liver, spleen, and intestine: toxic effects were greater with free-CDDP than SpHL-CDDP. CONCLUSION: SpHL-CDDP showed significant antitumor activity in pancreatic cancer-bearing mice, with lower toxicity in comparison with free-CDDP.
