Irreversible Electroporation of the Liver Increases the Transplant Engraftment of Hepatocytes

Abstract

Introduction: Irreversible electroporation (IRE) is a tissue ablation technology that kills cells with short electrical pulses that do not induce thermal damage, thereby preserving the extracellular matrix. Preclinical research suggests that IRE may be developed as a tool for regenerative surgery by clearing existing host cells within a solid organ and creating a supportive niche for new cell engraftment. We hypothesized that hepatocytes transplanted by injection into the portal circulation would preferentially engraft within liver parenchyma pretreated with IRE.

Methods: Transgene-positive β-galactosidase-expressing hepatocytes were isolated from B6.129S7-Gt(ROSA)26Sor/J (ROSA26) mice and transplanted by intrasplenic injection into wild-type littermates that received liver IRE pretreatment or control sham treatment. Engraftment of donor hepatocytes in recipient livers was determined by X-gal staining.

Results: Significantly higher numbers of X-gal⁺ donor hepatocytes engrafted in the livers of IRE-treated mice as compared to sham-treated mice. X-gal⁺ hepatocytes persisted in IRE-treated recipients for at least 11 d post-transplant and formed clusters. Immunostaining demonstrated the presence of HNF4A/Ki67/β-galactosidase triple-positive cells within IRE-ablation zones, indicating that transplanted hepatocytes preferentially engrafted in IRE-treated liver parenchyma and proliferated.

Conclusions: IRE pretreatment of the liver increased engraftment of transplanted hepatocytes within the IRE-ablation zone. IRE treatment of the host liver may be developed clinically as a strategy to increase engraftment efficiency of primary hepatocytes and/or hepatocytes derived from stem cells in cell transplant therapies.

Keywords: Cellular transplantation; Engraftment; Hepatocyte; Irreversible electroporation; Liver; Regeneration.