In vivo activity of bleomycin incorporated with biodegradable poly-d,l-lactic acid and implanted in the mediastinum of dogs.

The possible usefulness of bleomycin incorporated with biodegradable poly-d, l-lactic acid (BLM-PLA) for targeting chemotherapy for esophageal cancer was studied in vivo. Local levels of BLM after administration were compared with those after injection of BLM-SOL, an aqueous solution of BLM. BLM-PLA or BLM-SOL was administered into the upper mediastinum under a right thoracotomy in 36 mongrel dogs. On days 10, 20, and 30 after administration, connective tissues, lymph nodes, lung, liver, kidney, and spleen were removed, and BLM activity was measured. High activity of BLM was detected for 30 days after BLM-PLA administration in both the connective tissues and the lymph nodes, compared with BLM-SOL administration. BLM activity was low in the other organs after BLM-PLA administration. BLM in the blood was significantly lower after administration of BLM-PLA than BLM-SOL. The results indicate that BLM-PLA may become a useful tool in targeting chemotherapy for esophageal cancer.