Background: A small nose-only exposure chamber was evaluated for inhalation delivery of drug carrier systems (DCSs) to mice for the treatment of lung cancer. The chamber then was used for inhalation delivery of an anticancer drug, antisense oligonucleotides (ASO), and small interfering RNA (siRNA) directly to the cancerous lungs of mice. Methods: The uniformity of particle delivery across the ports of the exposure chamber and stability of the DCS (liposomes) during continuous aerosolization by a Collison nebulizer were examined. The mean produced particle size by number was approximately 130 nm, and the mass median diameter was approximately 270 nm. The system was then used to deliver DCS containing doxorubicin (DOX) and ASO or siRNA targeted to multidrug resistance-associated protein 1 (MRP1) mRNA as suppressors of cancer cell resistance. The retention of the drug in the lungs and the effect on tumor size were compared after inhalation delivery and intravenous injection in a nu/nu mouse model of lung cancer. Results: The aerosol mass across the four inhalation ports had a coefficient of variation of less than 12%, and approximately 1.4% of the nebulized mass was available for inhalation at each port. The mean size of 130 nm of liposomal DCS did not change significantly during continuous 60-min aerosolization. For inhalation delivery of DCS with DOX+ASO/siRNA, the amount of drugs available for inhalation was lower compared with intravenous injection of DOX; however, the observed lung dose and the retention time were significantly higher. The delivery of DOX+ASO/siRNA via inhalation resulted in tumor volume reduction of more than 90%, whereas only about 40% reduction was achieved after intravenous injection of DOX. Conclusions: The investigated exposure system is suitable for inhalation delivery of complex DCS, and its use to deliver DCS containing anticancer drugs and resistance suppressors via inhalation offered a superior method for lung cancer treatment in mice compared with intravenous injections.

This article presents a dual-wavelength band broadband photoacoustic spectroscopy technique ideally suited with low energy broadband sources for industrial and environmental multi-gas sensing applications. The broad spectral range of the supercontinuum source is used to cover a wide range of absorption bands of various gases. The major limitation in most of the gas sensors with broadband sources is the effect of interference between gases. This paper proposes a dual-wavelength technique to eliminate the impact of cross-sensitivity among gases. This sensor exhibits a comprehensive concentration measurement from part per million (ppm) to % levels. The proposed technique showed a ±1.2% error between the calculated and calibrated concentration values. We achieved a minimum detection limit (MDL) of 0.4 ppm, 0.7 ppm for methane (CH ₄ ) with an integration time of 142 s and 200 s using 2315 nm and 1650 nm band, respectively, 0.3 ppm, 1.8 ppm of ammonia (NH ₃ ) with an integration time of 100 s and 48 s using 2315 nm and 2017 nm band, respectively, also 2.6 ppm of carbon monoxide (CO) with an integration time of 71 s using 2315 nm band.