Soft tissues, like lungs, easily collapse during the transport and slicing. However, a major breakthrough called the precision-cut lung slices (PCLS) came by infusion of the airways of lungs with heated liquid agarose, which solidified at temperatures below 25 °C and therefore have the advantage to maintain the tissue structure. Among ex vivo models, PCLS technology offers many advantages including:
- The preservation of anatomy including alveolar architecture, respiratory parenchyma, structural and immune cell populations, and connective tissue.
- PCLS provides three-dimensional lung tissue slices that retain the majority of intact lung cells and their function.
- The slices containing cells are biologically active and the segments are similar to the condition found in vivo.
- Slices can be cryopreserved and used in culture studies from explanted human lungs particularly those with rare disorders.
- The slices are able to accurately reflect any changes to the underlying extracellular matrix associated with the disease.
- PCLS can be regarded as a “mini” lung that can be studied in the context of asthma, COPD, idiopathic pulmonary fibrosis, allergy, infections as well as in toxicology studies.
- PCLS has also been utilized to evaluate alternative targets for testing different therapeutic agents in addition to its use in toxicological studies.
- Frozen-thawed PCLSs show significant metabolic activity.
The tissue slices can be subsequently cultured with drug candidates or test substances. After several hours or days, the tissue response can be observed. For example, the airways in the tissue slices may show microscopic alterations, or release of signaling molecules can be found. In addition, they use this model to study the effects of new drugs – at an early stage of drug development.
Lung samples from research-consented donors with a number of pulmonary abnormalities can be collected, cut and frozen and shipped to the entire US.