Cisplatin (CDDP) intravenous treatments suffer several dose-limiting toxicity issues. Hyaluronan (HA), a naturally occurring biopolymer in the interstitium, is primarily cleared by the lymphatic system. An alteration in input rate and administration route through pulmonary delivery of hyaluronan-cisplatin (HA-Pt) conjugate may increase local lung CDDP concentrations and decrease systemic toxicity. Sprague-Dawley rats were split into four groups: i.v. CDDP (3.5 mg/kg), i.v. HA-Pt conjugate (3.5 mg/kg equivalent CDDP), lung instillation CDDP and lung instillation HA-Pt conjugate. Total platinum level in the lungs of the HA-Pt lung instillation group was 5.7-fold and 1.2-fold higher than the CDDP intravenous group at 24 and 96 h, respectively. A 1.1-fold increase of Pt accumulation in lung draining nodes for the HA-Pt lung instillation group was achieved at 24h relative to the CDDP i.v. group. In the brain and kidneys, the CDDP i.v. group had higher tissue/plasma ratios compared to the HA-Pt lung instillation group. Augmented tissue distribution from CDDP i.v. could translate into enhanced tissue toxicity compared to the altered input rate and distribution of the intrapulmonary nanoformulation. In conclusion, a local pulmonary CDDP delivery system was developed with increased platinum concentration in the lungs and draining nodes compared to i.v. therapy.
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