IPL- Isolated-perfused lung

At Fraunhofer ITEM, the IPL has recently been established as a tool for investigations into the systemic uptake of inhaled substances through the lung. To this end, lungs from rats are ventilated and perfused with a physiologic buffer solution. Respiratory parameters, such as tidal volume, dynamic compliance, and pulmonary arterial pressure (VT, Cdyn, PAP), are measured online for monitoring of pulmonary viability.

For investigations into mass transfer processes through the lung, IPLs are exposed to rat-respirable aerosols. The concentration profile of the substance is subsequently analyzed in the perfusate.

Studies at Fraunhofer ITEM have shown that the analysis of such concentration profiles for small molecules delivered to the lungs as aerosols enables a qualitative ranking in regard to the transfer velocity through the lung into the systemic circulation, which is in good agreement with data from human clinical trials.

These experiments as well as further studies performed at Fraunhofer ITEM show a strong potential of the model for systematic investigations of mass transfer through the lung for different substances, though a quantitative comparison to the human situation and in this context between different products has not been carried out yet. In the context of absorption studies, the IPL model is also useful for further mechanistic investigations, such as the elucidation of transport-relevant mechanisms through the alveolar-epithelial membrane.