The Strategy Of Decellularization/Recellularization And (Liver) Organ Replacement

End-stage liver disease(ESLD)is a common clinically important disease,mainly including acute liver failure and chronic cirrhosis.Liver transplantation is the only treatment option,but the biggest problem facing the transplantation community today is the extreme shortage of organs.Biological tissue engineering offers a new direction to solve this problem.The decellularization/recellularization strategy can completely preserve the extracellular skeleton of the organ(liver)has consequently become a key technology for organ remodeling,such as liver,pancreas,heart,bile,lung,kidney.Since the na?ve decellularized liver scaffold(nDLS)lacks the necessary active substances,optimizing the scaffolds material including nDLS remain a problem to be solved in the academic field.This study uses a regenerative liver scaffold to solve this problem,and shows that the regenerative decellularized liver scaffold(rDLS)can create a liver regeneration microenvironment that improve efficient survival of seed cells,promote smooth blood flow and liver organogenesis compared with nDLS.1"natural liver regeneration microenvironment"characteristics of rDLSrDLS was obtained from a 30-55%partial hepatectomy that was maintained in vivo for 3-5 days and then perfused with detergent in vitro.Compared to nDLS,its extracellular matrix component expressed cytokines which were essential for liver regeneration,e.g.TNF-α,which made rDLS have an"active microenvironment".2 Improve the survival efficiency of primary hepatocytesThe primary hepatocytes obtained by the isolation were planted on rDLS for Ki-67 staining and trypan blue activity assay.It was found that the survival rate of hepatocytes in rDLS was significantly higher than that of nDLS,indicating that the compatibility of rDLS was better than that of rDLS.3 Facilitate the flow of blood between donor and recipient after transplantationThe in vitro and in vivo blood flow function evaluation model and Doppler blood flow evaluation showed that the ability to promote endothelial cell differentiation of rDLS was better than that of nDLS.This showed that the“active microenvironment”of rDLS had the effect of blood flow-function reconstruction.4 Induce the potential of stem cells in(liver)organogenesisNG2~+HPCs were planted on rDLS,cultured in vitro or transplanted into mice.Its(liver)organ formation ability was superior to nDLS.Further studies found that this ability is related to pluripotency.In summary,rDLS provides new scaffolding materials for biological tissue engineering.Chronic cirrhosis is a chronic progressive disease in which connective tissue proliferates due to persistent damage to liver cells.Although using exogenous stem cells has become a new idea for treatment,the activity of endogenous stem cells in chronic cirrhosis is still incompletely understood.Hence,this study aims to investigate the survival of endogenous hepatocytes in chronic cirrhosis.We used the established diethylnitrosamine(DEN)-induced liver cirrhosis model in C57BL/6 mice,randomly selected mice liver specimens every week,and performed specific histological staining to pathohistologically identify,isolate and culture stem cells.The inflammatory activity grade(G)was aaseesd via hematoxylin-eosin staining(H&E)and fibrosis stage(S)was observed using Masson’s Trichrome.Neuron-glial antigen 2 hepatic stem/progenitor cells(NG2+HPCs)were isolated using the "Percoll-Plate-Wait" method until 12 weeks of tumor formation.1 Pathological grading and staging Liver pathology was graded according to the 2007 International Simplified Grading and Staging System(inflammation was divided into G1-G4 and fibrosis into S1-S4).The results showed that inflammation occurred during the 1st week,fibrosis occurred in the 3rd week,G/S gradually increases with increasing age,inflammation reached G4 level at the 8th week,and the degree of fibrosis reached S4 stage at the 11 th week.2 G/S correlation According to the International Simplified Grading and Staging System,the G/S was positively correlated before S2 stage,and had no correlation after the S3 stage.3 Correlation between endogenous hepatocytes and fibrosis The endogenous stem cell culture results showed that stem cells survived within 3and 8 weeks,decreased their activity within 9-10 weeks,and tended to die after 11weeks(fibrosis was at the S3 stage).Thus,stem cells survived in the S1-S2 stage,and may die or lose activity in the S3-S4 stage.