Prolonged Preservation and Evaluation of Human Lungs With Portable Normothermic EVLP

Advances in bioreactors for lung bioengineering: From scalable cell culture to tissue growth monitoring

Lung bioengineering has emerged to resolve the current lung transplantation limitations and risks, including the shortage of donor organs and the high rejection rate of transplanted lungs. One of the most critical elements of lung bioengineering is bioreactors. Bioreactors with different applications have been developed in the last decade for lung bioengineering approaches, aiming to produce functional reproducible tissue constructs. Here, the current status and advances made in the development and application of bioreactors for bioengineering lungs are comprehensively reviewed. First, bioreactor design criteria are explained, followed by a discussion on using bioreactors as a culture system for scalable expansion and proliferation of lung cells, such as producing epithelial cells from induced pluripotent stem cells (iPSCs). Next, bioreactor systems facilitating and improving decellularization and recellularization of lung tissues are discussed, highlighting the studies that developed bioreactors for producing engineered human-sized lungs. Then, monitoring bioreactors are reviewed, showing their ability to evaluate and optimize the culture conditions for maturing engineered lung tissues, followed by an explanation on the ability of ex vivo lung perfusion systems for reconditioning the lungs before transplantation. After that, lung cancer studies simplified by bioreactors are discussed, showing the potentials of bioreactors in lung disease modeling. Finally, other platforms with the potential of facilitating lung bioengineering are described, including the in vivo bioreactors and lung-on-a-chip models. In the end, concluding remarks and future directions are put forward to accelerate lung bioengineering using bioreactors.

How to build a lung: latest advances and emerging themes in lung bioengineering

Chronic respiratory diseases remain a major cause of morbidity and mortality worldwide. The only option at end-stage disease is lung transplantation, but there are not enough donor lungs to meet clinical demand. Alternative options to increase tissue availability for lung transplantation are urgently required to close the gap on this unmet clinical need. A growing number of tissue engineering approaches are exploring the potential to generate lung tissue ex vivo for transplantation. Both biologically derived and manufactured scaffolds seeded with cells and grown ex vivo have been explored in pre-clinical studies, with the eventual goal of generating functional pulmonary tissue for transplantation. Recently, there have been significant efforts to scale-up cell culture methods to generate adequate cell numbers for human-scale bioengineering approaches. Concomitantly, there have been exciting efforts in designing bioreactors that allow for appropriate cell seeding and development of functional lung tissue over time. This review aims to present the current state-of-the-art progress for each of these areas and to discuss promising new ideas within the field of lung bioengineering.