Bioengineered functional humanized livers: An emerging supportive modality to bridge the gap of organ transplantation for management of end-stage liver diseases

Table 3 List of recent studies reporting use of omentum as transplantation site to support the lost organ function from ectopic transplantation of engineered tissues or grafts

Animal model	Site of transplantation	Mode of graft used	Results	Reference
Femoral bone of New Zealand rabbit was	Greater omentum on the left side	Free transplant of the greater omentum	Process of the callus formation and its mineralisation are much quicker and thicker on the defect that was covered with the free transplant of the greater omentum.	[107]
Pancreatectomized dogs	Spleen or Omentum	Islet auto-transplantation	Beta cell response to mild non-insulin induced hypoglycemia was normal, whereas the alpha cell response was not.	[108]
Murine carotid artery injury model	Omentum was applied to the injured vessel	Omentum + Omental progenitor cells	Omentum can directly contribute reparative progenitor cells to injured tissues upon treatment with Tβ4.	[109]
Nondiabetic nude rats	Omentum/kidney capsule	Perinatal porcine islet cell grafts	In both sites, the A-cell volume increased fourfold between weeks 1 and 10 reflecting a rise in A-cell number. In the omental implants, however, the cellular insulin reserves and the percent of proliferating cells were twofold higher than in kidney implants. In parallel, the blood vessel density in omental implants increased twofold, reaching a density comparable with islets in adult pig pancreas.	[110]
Diabetic rat and nonhuman primate (NHP) models	Intra-omental	In situ-generated adherent, resorbable plasma thrombin biologic scaffold	Improved metabolic function and preservation of islet cytoarchitecture, with reconstitution of rich intrainsular vascular networks in both species.	[21]
Adult male Spraguee Dawley rats	Omental transposition	Hepatic tissue sutured into the omentum mobilization of the omentum and transposition onto the left hepatic lobe	Omental transposition provided adequate microcirculation for proliferation of ectopic hepatic cells after liver resection.	[111]