Engineering Modular 3D Liver Culture Microenvironments In Vitro to Parse the Interplay between Biophysical and Biochemical Microenvironment Cues on Hepatic Phenotypes

Modeling Tumor Cell Dormancy in an Ex Vivo Liver Metastatic Niche

Despite decades of research into metastatic disease, our knowledge of the mechanisms governing dormancy are still limited. Unraveling the process will aid in developing effective therapies to either maintain or eliminate these dormant cells and thus prevent them from emerging into overt metastatic disease. To study the behavior of dormant tumor cells-mechanisms that promote, maintain, and disrupt this state-we utilize the Legacy LiverChip®, an all-human ex vivo hepatic microphysiological system. This complex, bioengineered system is able to recreate metastatic disease that is reflective of the human situation and is among only a handful of systems able to mimic spontaneous tumor cell dormancy. The dormant subpopulation reflects the defining traits of cellular dormancy-survival in a foreign microenvironment, chemoresistance, and reversible growth arrest. This microphysiological system has and continues to provide critical insights into the biology of dormant tumor cells. It also serves as an accessible tool to identify new therapeutic strategies targeting dormancy and concurrently evaluate the efficacy of therapeutic agents as well as their metabolism and dose-limiting toxicity.

Liver-on-a-chip: Considerations, advances, and beyond

The liver is the largest internal organ in the human body with largest mass of glandular tissue. Modeling the liver has been challenging due to its variety of major functions, including processing nutrients and vitamins, detoxification, and regulating body metabolism. The intrinsic shortfalls of conventional two-dimensional (2D) cell culture methods for studying pharmacokinetics in parenchymal cells (hepatocytes) have contributed to suboptimal outcomes in clinical trials and drug development. This prompts the development of highly automated, biomimetic liver-on-a-chip (LOC) devices to simulate native liver structure and function, with the aid of recent progress in microfluidics. LOC offers a cost-effective and accurate model for pharmacokinetics, pharmacodynamics, and toxicity studies. This review provides a critical update on recent developments in designing LOCs and fabrication strategies. We highlight biomimetic design approaches for LOCs, including mimicking liver structure and function, and their diverse applications in areas such as drug screening, toxicity assessment, and real-time biosensing. We capture the newest ideas in the field to advance the field of LOCs and address current challenges.