Percutaneous intratumoral injection of cisplatin microspheres in tumor-bearing rats to diminish acute nephrotoxicity

Poly(o,L-lactlde) microspheres loaded with cisplatin (PLA-CDDP MS) were prepared by a solvent evaporation technique for direct Intratumoral ln|ectlon. The microspheres, 50-100 |im, containing 40.04% of cisplatin produce sustained release In vitro. PLA-CDDP MS (6 mg/kg body weight of cisplatin) suspensions were Injected Intratumorally Into mammary tumors In rats. Cisplatin solution (6 mg/kg body weight) was Injected either Intratumorally or Intraperltoneally In two groups. After treatments, the tumor size decreased In each of the groups as a function of time. Sixteen days post-Injection, the tumors had either disappeared or significantly shrunk. PLA-CDDP MS had a similar antltumor effect compared with cisplatin aqueous solution. Blood urea nitrogen, serum creatlnlne and hlstopathology examinations revealed that the renal toxlclty In the PLA-CDDP MS group was significantly less than In the control groups. These results indicate that intratumoral injection of PLACDDP MS maintains antlcancer potency and reduces acute renal toxlclty.