>Cellular repopulation has been used for years, a process that injects healthy liver cells into the patient’s damaged organ through a portal vein where they adhere themselves to the existing cellular scaffolding and grow into new, functional liver tissue.

>Creating an immediately available and inexhaustible supply of functioning liver cells from autologous tissue would allow early intervention in patients with hepatic failure and would allow liver cells to be infused over a longer period of time,” the 2016 study’s authors note. “Combined with recent advances in genome-editing technology, such liver cells could be used widely to treat devastating liver-based inborn errors of metabolism and to eliminate the need for a life-long regimen of immunosuppressive drugs and their complications.” The downside to this technique is the pace at which the donor cells proliferate, making it a poor tool against acute liver failure.

>Extracellular Vesicle-based therapies, on the other hand, leverage the body’s intracellular communications pathways to deliver drugs with, “high bioavailability, exceptional biocompatibility, and low immunogenicity,” according to 2020’s Extracellular Vesicle-Based Therapeutics: Preclinical and Clinical Investigations. “They provide a means for intercellular communication and the transmission of bioactive compounds to targeted tissues, cells, and organs” including “fibroblasts, neuronal cells, macrophages, and even cancer cells.”

>EVs are the postal letters that cells send one another. They come in a variety of sizes from 30 to 1000 nm and have exterior membranes studded with multiple adhesive proteins that grant them entry into any number of different types of cells. Exploiting the biological equivalent to a janitor’s key ring, researchers have begun tucking therapeutic nanoparticles into EVs and using them to discreetly inject treatments into the targeted cells. However, these treatments are still in the experimental stages and are most effective against acute liver failure and inborn metabolic diseases rather than end-stage liver failure.