Evolution of graft morphology and function after recellularization of decellularized rat livers

Abstract

Decellularization of livers is a well-established procedure. Data on different reseeding techniques or the functional evolution and reorganization processes of repopulated grafts remains limited. A proprietary, customized bioreactor was established to repopulate decellularized rat livers (n = 21) with primary rat hepatocytes (150 × 10 cells) via the hepatic artery and to subsequently evaluate graft morphology and function during 7 days of ex vivo perfusion. Grafts were analysed at 1 h, 6 h, 12 h, 24 h, 3 days, 5 days and 7 days after recellularization (all n = 3) by immunohistological evaluation, hepatocyte-related enzyme (aspartate transaminase, alanine transaminase and lactate dehydrogenase) and albumin measurement in the perfusate. This appears to be the first available protocol for repopulation of rat livers via the hepatic artery. Within the first 24 h after repopulation, the hepatocytes seemed to migrate out of the vascular network and form clusters in the parenchymal space around the vessels. Graft function increased for the first 24 h after repopulation with a significantly higher function compared to standard two-dimensional culture after 24 h. Thereafter, graft function constantly decreased with significantly lower values after 6 days and 7 days of perfusion, although histologically viable hepatocytes were found even after this period. The data suggests that, owing to a constant loss of function, repopulated grafts should potentially be implanted as soon as cell engraftment and graft re-organization are completed. Copyright © 2016 John Wiley & Sons, Ltd.

Strategies based on organ decellularization and recellularization

“…Studies investigating whether this approach is feasible are lacking. Several studies have successfully achieved reendothelialization (with or without coating the remaining ECM) and parenchymatous recellularization of liver scaffolds in vitro [8,20,64,73,112,113,[116][117][118][119][120][121][122][123]. Various cell types, such as hepatocytes (e.g.…”

“…The existing studies have achieved an in vitro cultivation of the neo-livers for up to 28 days and revealed restored functionality (e.g. albumin secretion, urea production, ammonium metabolism and enzyme regulation), drug metabolism and viability of the seeded cells [8,20,64,73,79,81,112,113,[116][117][118][119]121]. According to Robertson et al, recellularized livers produce albumin and metabolize midazolam until the end of their study at 28 days.…”

Physical Properties of the Extracellular Matrix of Decellularized Porcine Liver

“…The recellularization of the decellularized tissue should be optimized in order to fabricate a functional reconstructed liver. Previous reports suggested that recellularized liver inoculated with hepatocytes expresses liver-specific functions such as albumin and urea synthesis [5,6]. Also, site-specific cell inoculation has been successfully performed [7].…”

Development of Bioengineered Organ Using Biological Acellular Rat Liver Scaffold and Hepatocytes

“…Thus, allowing liver reconstruction by authentic cell-cell and cell-matrix interactions, which are essential for cell differentiationand maintenance of specialized function. 29 In another study by Butter et al 30 it was suggested, to utilize the repopulated grafts soon after cell engraftment and graft re-organization to avoid loss of functional hepatocytes.…”