Hepatic stellate cell A decreases progressively in liver injury. The activated stellate cell is also responsible for secreting collagen scar tissue, which can lead to cirrhosis. More recent studies have also shown that in vivo activation of hepatic stellate cells by agents causing liver fibrosis can eventually lead to senescence in these cells, marked by increased SA-beta-galactosidase staining, as well as p53 accumulation and activation of Rb–hallmarks of cellular senescence. Senescent hepatic stellate cells have been demonstrated to limit liver fibrosis by activating interactions with NK cells. The cells of Ito were named for Toshio Ito, a twentieth-century Japanese physician, who introduced a
Organ-on-a-chip models that replicate aspects of the human body as closely as possible and give examples that demonstrate their potential use in drug development, such as identifying synergistic drug interactions as well as simulating multi-organ metabolic interactions. Multi compartment micro fluidic-based devices, particularly those that are physical representations of physiologically based pharmacokinetic (PBPK) models that represent the mass transfer of compounds in compartmental models of the mammalian body, may contribute to improving the drug development process. Mathematical pharmacokinetic (PK) models aim to estimate concentration-time profiles within each organ on the basis of the initial drug dose. Such mathematical models can be