New Folate-Grafted Chitosan Derivative To Improve Delivery of Paclitaxel-Loaded Solid Lipid Nanoparticles for Lung Tumor Therapy by Inhalation.

Inhaled chemotherapy for the treatment of lung tumors requires that drug delivery systems improve selectivity for cancer cells and tumor penetration and allow sufficient lung residence. To this end, we developed solid lipid nanoparticles (SLN) with modified surface properties. We successfully synthesized a new folate-grafted copolymer of polyethylene glycol (PEG) and chitosan, F-PEG-HTCC, with a PEG-graft ratio of 7% and a molecular weight range of 211-250 kDa. F-PEG-HTCC-coated, paclitaxel-loaded SLN were prepared with an encapsulation efficiency, mean diameter, and zeta potential of about 100%, 250 nm, and +32 mV, respectively. The coated SLN entered folate receptor (FR)-expressing HeLa and M109-HiFR cells in vitro and M109 tumors in vivo after pulmonary delivery. The coated SLN significantly decreased the in vitro half-maximum inhibitory concentrations of paclitaxel in M109-HiFR cells (60 vs 340 nM, respectively). We demonstrated that FR was involved in these improvements, especially in M109-HiFR cells. After pulmonary delivery in vivo, the coated SLN had a favorable pharmacokinetic profile, with pulmonary exposure to paclitaxel prolonged to up to 6 h and limited systemic distribution. Our preclinical findings therefore demonstrated the positive impact of the coated SLN on the delivery of paclitaxel by inhalation.

In vivo assessment of temozolomide local delivery for lung cancer inhalation therapy.

The aim of this study was to compare the efficacy of local drug delivery by inhalation to intravenous delivery in a B16F10 melanoma metastatic lung model. Temozolomide was formulated as a suspension, which was elaborated and evaluated in terms of particle size, shape and agglomeration. An endotracheal administration device was used to aerosolise the suspension. This mode of delivery was evaluated at different temozolomide concentrations and was optimized for the uniformity of delivered dose, the droplet size distribution and the distribution of droplets in vivo. Of the particles in the stabilised suspension, 79% were compatible with the human respirable size range, and this formulation retained 100% in vitro anticancer activity as compared to temozolomide alone in three distinct cancer cell lines. The pulmonary delivery device provided good reproducibility in terms of both the dose delivered and the droplet size distribution. Most of the lung tissues that were exposed to aerosol droplets contained the particles, as revealed by fluorescent microscopy techniques. The global in vivo antitumour activity of the inhaled temozolomide provided a median survival period similar to that for intravenous temozolomide delivery, and three out of 27 mice (11%) survived with almost complete eradication of the lung tumours. The present study thus shows that inhalation of a simple liquid formulation is well tolerated and active against a very biologically aggressive mouse melanoma pulmonary pseudo-metastatic model. This inhalation delivery could be used to deliver other types of anticancer drugs.