Inhalation Sciences Sweden AB, Stockholm, Sweden.
J Aerosol Med Pulm Drug Deliv. 2010 Oct;23(5):273-84. doi: 10.1089/jamp.2009.0790.
Our aim was to investigate the potential of the DustGun aerosol technology integrated with the isolated, perfused, and ventilated lung of the rat (IPL) to study the pulmonary disposition of an inhaled model biopharmaceutical, the 40-kDa protein horseradish peroxidase (HRP).
The DustGun aerosol technology was used to deliver respirable powder aerosols of HRP (the mass median aerodynamic diameter: 1.7 μm) as an 80-sec bolus to the IPL perfused in a single-pass mode. Lung perfusate was repeatedly sampled for 125 min after the HRP exposure. The amount of active HRP clearing with the perfusate or being retained in the lung was measured enzymatically.
The total amount of HRP deposited in the lungs was 335 ± 100 μg and 568 ± 47 μg for a low- and high-dose exposure, respectively. After inhalation, the initial appearance of HRP in the perfusate was rapid. However, the total amount of HRP that cleared with the perfusate remained below 0.5% of the deposited dose. The effect of opening the tight junctions between the alveolar epithelial cells on HRP absorption was studied by exposing the IPL to nebulized aerosols of either 0.02, 0.2, or 2% poly-L-Arginine (PLA) (MW 42.5 kDa) in phosphate-buffered saline (PBS) for 5 min, at 40 min after the HRP exposure. Subsequent exposure to 0.02% PLA did not affect HRP absorption. However, exposure to 0.2% PLA increased the absorption rate ninefold, and the total amount of HRP clearing with the perfusate increased to approximately 4% of the deposited dose. No further increase was obtained with 2% PLA, indicating a steep dose-response for the enhancer. It was concluded that the pulmonary absorption of HRP is quite slow, and absorption enhancers affecting tight junctions have a distinctive, yet limited efficiency. The presented inhalation technology can be very useful in studying the pulmonary absorption of biopharmaceuticals.
我们的目的是研究 DustGun 气溶胶技术与大鼠离体、灌注和通气肺（IPL）的结合潜力，以研究吸入模型生物制药——40kDa 蛋白辣根过氧化物酶（HRP）在肺部的分布情况。
使用 DustGun 气溶胶技术以 80 秒的时间间隔将可吸入 HRP 粉末气溶胶（质量中值空气动力学直径：1.7μm）作为 80 秒的单次传递方式输送到 IPL 中。在 HRP 暴露后，重复采集肺灌流液 125 分钟。用酶法测量随灌流液清除或保留在肺中的活性 HRP 量。
低剂量和高剂量暴露时，沉积在肺中的 HRP 总量分别为 335±100μg 和 568±47μg。吸入后，HRP 迅速出现在灌流液中。然而，随灌流液清除的 HRP 总量仍低于沉积剂量的 0.5%。通过用雾化的 0.02%、0.2%或 2%聚-L-精氨酸（PLA）（MW 42.5kDa）在 HRP 暴露后 40 分钟时对 IPL 暴露 5 分钟，研究肺泡上皮细胞之间的紧密连接对 HRP 吸收的影响。随后用 0.02% PLA 暴露不会影响 HRP 吸收。然而，用 0.2% PLA 暴露会使吸收速率增加九倍，随灌流液清除的 HRP 总量增加到约沉积剂量的 4%。用 2% PLA 不会再增加，表明增强剂的剂量反应陡峭。结果表明，HRP 的肺部吸收非常缓慢，影响紧密连接的吸收增强剂具有显著但有限的效率。所提出的吸入技术在研究生物制药的肺部吸收方面非常有用。
