Intestinal toxicity evaluation of long-circulating and pH-sensitive liposomes loaded with cisplatin.

Cisplatin (CDDP) is a chemotherapeutic agent widely used in several anticancer protocols for instance head and neck, testicle, ovarian, lung and peritoneal carcinomatosis. According to the literature, the use of CDDP is associated with several side effects; among them, we highlighted the mucositis. CDDP, when administered by IP, promoted significant intestinal epithelium alterations in an experimental model. Our research group has proposed that the incorporation of CDDP into long-circulating and pH-sensitive liposomes (SpHL-CDDP) could help to overcome some side effects induced by this drug. Thus, we evaluated signs of intestinal toxicity 24h and 72h after the administration of a single i.p dose of free CDDP or SpHL-CDDP to healthy Swiss mice. Twenty-four hours after administration of free CDDP, the mice showed signs of intestinal toxicity, principally weight loss, increased intestinal permeability associated with a decrease in expression of tight junctions, and histological damage with the presence of inflammatory infiltrates and activation of ERK1/2 and NF-κB. These changes persisted after 72h. While signs of intestinal toxicity were also observed 24h after administration of SpHL-CDDP, after 72h body weight and intestinal permeability of mice in this group were similar to those of mice in the control group. In comparison with the free CDDP treatment group, 72h after treatment mice in the SpHL-CDDP group showed better histological parameters, lower levels of inflammatory infiltrate with increased IL-10 and IgA levels, and less activation of caspase-3, ERK1/2 and NF-κB. These differences could account for the recovery of the intestinal epithelium observed in mice treated with SpHL-CDDP but not in mice treated with free CDDP. In conclusion, here we show that encapsulation of CDDP in SpHL lessens intestinal damage and that, as such, SpHL-CDDP is a promising candidate for clinical use.