Liver transplantation remains the only definitive treatment for end-stage liver disease¹^,²^,³. However, the critical shortage and declining quality of donor organs have heightened the need for alternative treatments⁴. In the realm of regenerative medicine, bioartificial livers (BALs) utilizing decellularized liver matrix (DLM) have emerged as promising solutions⁵^,⁶^,⁷. The DLM preserves the original liver structure, including its intricate microvascular network and components of the ECM, offering a scaffold for creating transplantable BALs that could potentially alleviate liver diseases.

Despite the promise, the adoption of this technology faces challenges, particularly in sourcing suitable DLMs. Human-derived DLMs are in short supply, while those from animal sources carry the risks of disease transmission and immune rejection. In an innovative approach, our research has explored the use of a decellularized spleen matrix (DSM) as a foundation for BALs⁸^,⁹^,¹⁰^,¹¹. Spleens are more readily available in various medical situations, such as portal hypertension, traumatic rupture, idiopathic thrombocytopenic purpura, and donation after cardiac death. Therefore, spleens are more widely available than livers for research purposes. Patients who have undergone splenectomies do not suffer from severe conditions, further confirming the dispensability of the spleen. The microenvironment of the spleen, particularly the extracellular matrix and sinusoids, is similar to that of the liver. This makes the spleen a suitable organ for cell adhesion and proliferation in hepatocyte transplantation research. Based on these findings, our previous investigations have demonstrated that DSMs share comparable microstructures and components with DLMs and can support the survival and function of hepatocytes, including albumin and urea production. Furthermore, DSMs have been shown to enhance the hepatic differentiation of bone marrow mesenchymal stem cells, leading to improved and consistent functionality.

By employing DSMs treated with heparin, we have engineered functional BALs capable of demonstrating effective short-term anticoagulation and partial liver function compensation¹¹. Consequently, this three-dimensional DSM holds significant promise for the advancement of liver tissue engineering and cell therapy. In this work, we present the detailed methods of harvesting rat spleens and preparing DSM that preserve the microstructures and components of the ECM.

Rat Spleen Harvest for the Preparation of Decellularized Spleen Matrix