liver tissue engineering scaffold materials

A liver regenerative medicine-based approach (bioartificial devices (BALs) and a liver on-a-chip platform) has been recently explored, aiming to temporarily support the organ until transplantation. Moreover, the inability of healthcare professionals to monitor graft health and the frequent cases of rejection limit the use of hepatocyte transplantation in clinical practice. Although the replacement of 5% of liver cells with primary hepatocytes could significantly improve liver function, the general problem with this approach is the limited repopulation capacity of engrafted cells partly due to instant blood-mediated inflammatory reaction (IBMIR). Hepatocyte transplantation has been tested for more than 20 years one approach involved injections of primary hepatocytes into the hepatic parenchyma with the aim of restoring liver activity and metabolic functions. In order to overcome the lack of donors, the development of new therapeutic options, such as cell-based therapies that include liver cell transplantations, bioartificial livers, and engineered hepatic tissues, is mandatory. This results in an increasing mismatch between the numbers of liver donors and recipients. In detail, data from the United States show that more than 15,000 patients have been added to the waiting list for liver transplantation, while only around 6000 liver transplants are actually performed yearly. Allogeneic liver transplantation is still considered the gold standard solution for end-stage organ failure, such as end-stage liver disease, providing a better quality of life in addition to cost effectiveness however, a shortage of donor organs has resulted in extended transplantation waiting lists. Liver dysfunction is one of the most severe health problems worldwide and is characterized by high morbidity and mortality. Future possible clinical applications in regenerative medicine for liver tissue engineering and for drug testing were underlined and dissected. The aim of the present review is to underline the recent developments in cell-on-scaffold technology for liver bioengineering, taking into account: (1) biological and synthetic scaffolds (2) animal and human tissue decellularization (3) scaffold recellularization (4) 3D bioprinting and (5) organoid technology. It has been frequently reported that an extracellular matrix-based scaffold offers a structural support and important biological molecules that could help cellular proliferation during the recellularization process. In the last several years, organ bioengineering has been extensively explored to provide transplantable tissues or whole organs with the final goal of creating a three-dimensional growth microenvironment mimicking the native structure. In order to overcome the lack of donors, the development of new therapeutic options is mandatory. Allogeneic liver transplantation is still deemed the gold standard solution for end-stage organ failure however, donor organ shortages have led to extended waiting lists for organ transplants.

Liver tissue engineering scaffold materials