Biofabricated Adipose-Derived Mesenchymal Cell Sheets Recover Cryo-Injured Kidneys in Rats

This study aimed to develop a treatment for chronic kidney disease (CKD) by investigating whether transplantation of biofabricated adipose-derived mesenchymal cell (AMC) sheets could improve renal tissue and function. Thirty-nine ten-week-old male Sprague-Dawley rats underwent the harvesting of adipose tissues and right nephrectomy. AMCs that were collected from adipose tissues were labeled and cultured on temperature-responsive dishes and applied to a gelatin hydrogel sheet. Subsequently, two identical AMC-gelatin sheets were attached together to biofabricate a bilayered AMC-gelatin sheet. Furthermore, 3 weeks after nephrectomy, the renal artery and vein of the left kidney were clamped, and the kidney was sprayed with liquid nitrogen for 60 s. The biofabricated AMC sheet was autologously transplanted into the renal capsule of the cryo-injured region (n = 14). Control rats were given acellular sheet (n = 25). One day before and 4 weeks after transplantation, blood and 24-h urinary specimens were collected. Histological analysis of the experimental kidneys was performed 4 weeks after transplantation. Four weeks after transplantation, in the acellular control-transplanted rats, creatinine clearance levels tended to increase, and serum creatinine levels significantly increased. However, in the biofabricated AMC sheet-transplanted rats, creatinine clearance levels significantly increased, and serum creatinine levels remained unchanged and were significantly lower than that of the control rats. The ratio of damaged to undamaged renal tubules in the AMC sheet-transplanted rats was lower than that in the control rats. In addition, the occupancy rate of fibrotic areas in the renal cortex under the AMC sheet-transplanted regions was significantly lower than that in the control regions. After transplantation, while the expressions of transforming growth factor-beta 1 and hypoxia-inducible factor-1 alpha were observed in both the control- and AMC sheet-transplanted regions, these expressions tended to be lower in the AMC sheet-transplanted rats than in the control rats. The labeled transplanted AMCs were detected in the transplanted regions, with some of them also showing positive staining for the vascular endothelial growth factor antibody. In conclusion, the biofabricated AMC sheets improved renal functions by ameliorating renal tubule disorders and renal fibrosis. Therefore, biofabricated AMC sheets would serve as a potential treatment for CKD.