p53 aerosol formulation with low toxicity and high efficiency for early lung cancer treatment

Purpose: To develop an optimal nonviral aerosol formulation for locoregional treatment of early lung cancer. Experimental Design: The formulation was made of polylysine/protamine combination (AND) as the carrier and p53 gene (p53sm) as therapeutic agent. To estimate the aerosol deposition, the aerodynamic size of the AND-p53sm was measured with extrusion-precipitation method. To accurately determine the dose, the aerosol efficiency in mice was measured with a fluorescent dye. The transfection efficiency and DNA protection function of the aerosolized formulation in cultured cells and mouse lungs were detected with reporter gene assays and/or reverse transcription-PCR. The preclinical safety and efficacy of AND-p53sm were studied in healthy mice and mice bearing orthotopic human non–small-cell lung cancer (NSCLC) xenograft. Results: After aerosolization, AND is 3- to 17-fold more effective than commonly used PEI or cationic lipid formulations in transfecting the NSCLC cells (relative light units, 1,494 versus 534 and 86; P P = 0.014). Inhalation of AND produced low and reversible pulmonary toxicity and no systemic toxicity. Conclusions: This optimal formulation is suitable for delivering biological materials to human lung with aerosol administration. This therapeutic strategy is an option for patients with early lung cancer and bronchoalveolar carcinoma.