# The Effect of Nutritional Supplementation in Ex Vivo Lung Perfusion Perfusate on Human Lung Endothelial Cell Function

## TL;DR

This study explores how adding specific nutrients to lung perfusion solutions improves lung cell function and survival during ex vivo lung perfusion.

## Contribution

The study introduces a high-throughput in vitro model to systematically evaluate the effects of specific nutritional supplements on lung endothelial cell function.

## Key findings

- GlutaMAX alone significantly reduced apoptosis and improved cell viability and migration compared to other supplements.
- Combining GlutaMAX, cysteine, and glycine further reduced apoptosis by targeting the glutathione synthesis pathway.

## Abstract

Clinical application of ex vivo lung perfusion (EVLP) has increased marginal donor lung utilization. It has been developed as a platform for donor lung reconditioning. However, many of the current repair strategies are limited by a maximum reliable EVLP circuit duration of 12 h. Past studies have successfully extended EVLP through nutrient supplementation, but the exact components and respective mechanisms by which EVLP is extended remains unknown. As such, the focus of this study was to systematically evaluate the effects of nutritional supplements in EVLP perfusates on cell apoptosis, viability, confluence, and migration. To test this, we developed a high-throughput human lung endothelial cell culture platform where experimental perfusates with various combinations of GlutaMAX (a glutamine dipeptide), Travasol (amino acids), Intralipid (lipids), Multi-12 (vitamins), cysteine, and glycine were tested using the Incucyte Live imaging system. GlutaMAX supplementation alone significantly reduced apoptosis, improved viability and cell migration beyond all other supplements and further outperformed standard endothelial cell culture medium. Travasol offered short-term benefits, while Intralipid offered minimal functional support. Multi-12 improved viability and apoptosis independently and in combination with other supplements. The best experimental perfusate targeted the glutathione synthesis pathway, combining GlutaMAX, cysteine and glycine and further reduced apoptosis compared with GlutaMAX alone. Collectively, these results suggest that nutrient selection during EVLP is critical and highlights the need to systematically evaluate perfusate modifications as opposed to broad-spectrum nutrient delivery. This in vitro model provides a cost-effective platform for preclinical screening of perfusate modifications to enhance organ viability during EVLP.