Question 1

What is decellularization in whole organ tissue culture?

Accepted Answer

Decellularization is the removal of all native cells from an excised donor organ while preserving its three-dimensional structure and extracellular matrix. This process uses detergent perfusion, where solutions like Triton and sodium deoxycholate systematically cleanse the organ of its cell population. The result is a sterile acellular organ matrix that serves as a scaffold for recellularization with new cells.

Question 2

How do bioreactors support organ recellularization?

Accepted Answer

Bioreactors dynamically culture organs by mimicking the native in vivo environment through mechanical stimulation and nutrient circulation. They use peristaltic pumps to simulate blood flow through the vasculature and ventilation systems to inflate organs like lungs. These specialized devices promote cell proliferation, attachment, and tissue growth by providing controlled conditions that replicate physiological signals, similar to principles found in batch and continuous bioreactors.

Question 3

What are the differences between autologous and allogenic cell transplantation?

Accepted Answer

Autologous cell transplantation uses cells from the recipient, which mitigates rejection and enhances biocompatibility of the engineered organ. Allogenic transplantation uses cells from a different donor and may be necessary when sufficient cells cannot be harvested from the recipient. Both approaches involve seeding specific cell types, such as stem cell lines, onto the decellularized organ matrix.

Question 4

What cell types are used to recellularize whole organs?

Accepted Answer

Whole organs are recellularized using specific cell types tailored to organ function. For lung culture, bone marrow-derived mesenchymal stem cells are used for airway seeding to recellularize the alveoli, while endothelial cells are introduced via peristaltic pump to recellularize small vessels. Established stem cell lines and autologous cells from the recipient are common choices for seeding the decellularized matrix.

Question 5

How is a donor lung prepared for whole organ culture?

Accepted Answer

Donor lungs are first cannulated with luer connectors in the pulmonary artery and trachea. Phosphate buffered saline containing heparin and sodium nitroprusside is perfused to remove blood and facilitate vessel dilation. The lungs are then inflated and permeated with deionized water, followed by submersion in detergent solutions like Triton and sodium deoxycholate to remove cells while preserving the organ matrix structure.

Question 6

What are practical applications of whole organ tissue culture beyond organ replacement?

Accepted Answer

Whole organ culture is used to test pharmaceutical agents and drug delivery devices by observing how experimental drugs are transported through organ tissue, providing realistic in vitro models of in vivo drug transfer. It also enables study of tissue behavior under various conditions, such as using bovine intervertebral discs with specialized bioreactors to understand how mechanical loading impacts disc degeneration mechanisms.

Question 7

How does histology confirm successful organ recellularization?

Accepted Answer

Histology is performed after tissue growth is complete to confirm attachment and growth of seeded cells on the decellularized matrix. The analysis shows whether mesenchymal stem cells and endothelial cells have successfully attached to the alveoli and small vascular vessels, creating tissue that resembles native lung architecture and demonstrating functional recellularization of the engineered organ.

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