Experimental study on paratumoral injection of cisplatin-loaded microspheres for gastric cancer.

Microspheres from glycolide-L-lactide copolymers incorporating cisplatin (CDDP-MS) were prepared to evaluate the sustained release and anticancer effect by paratumoral injection on the gastric cancer with regional lymphnode metastases induced by VX2 tumor in rabbits. In the first set of experiment, the rabbits were divided into three groups subjected to treatment and compared the tissue cisplatin distribution. In the first group (CDDP-MS pt group), 1 mg/kg of cisplatin was administered by the method of paratumoral injection in the form of CDDP-MS. In the second group (CDDP solution pt group), the same dose was given in the form of CDDP aqueous solution in the same way and in the third group (CDDP solution i.v. group), the same dose was intravenously administered. In the second set of experiment, after twice of each therapy the anticancer effects were compared between CDDP-MS pt and CDDP solution i.v. groups. In results, the platinum concentrations of the tumor and regional lymphnodes were 3.14 +/- 6.22, 0.65 +/- 0.79 micrograms/g in the first group, 0.43 +/- 0.39, 0.16 +/- 0.16 microgram/g in the second group and 0.03 +/- 0.01, 0.07 +/- 0.05 microgram/g in the third group, respectively.