Human hepatoma cell lines on gas foaming templated alginate scaffolds for in vitro drug-drug interaction and metabolism studies

Analysis of metabolites and metabolism-mediated biological activity assessment of ginsenosides on microfluidic co-culture system

In vivo, the complex process of drugs metabolism alters the change in drug composition and determines the final pharmacological properties of oral drugs. Ginsenosides are primary constituents of ginseng, whose pharmacological activities are greatly affected by liver metabolism. However, the predictive power of existing in vitro models is poor due to their inability to mimic the complexity of drug metabolism in vivo. The advance of organs-on-chip-based microfluidics system could provide a new in vitro drug screening platform by recapitulating the metabolic process and pharmacological activity of natural product. In this study, an improved microfluidic device was employed to establish an in vitro co-culture model by culturing multiple cell types in compartmentalized microchambers. Different cell lines were seeded on the device to examine the metabolites of ginsenosides from the hepatocytes in top layer and its resulting efficacy on the tumors in bottom layer. Metabolism dependent drug efficacy of Capecitabine in this system demonstrated the model is validated and controllable. High concentrations of CK, Rh2 (S), and Rg3 (S) ginsenosides showed significant inhibitory effects on two types of tumor cells. In addition, apoptosis detection showed that Rg3 (S) through liver metabolism promoted early apoptosis of tumor cells and displayed better anticancer activity than prodrug. The detected ginsenoside metabolites indicated that some protopanaxadiol saponins were converted into other anticancer aglycones in varying degrees due to orderly de-sugar and oxidation. Ginsenosides exhibited different efficacy on target cells by impacting their viabilities, indicating hepatic metabolism plays an important role in determining ginsenosides efficacy. In conclusion, this microfluidic co-culture system is simple, scalable, and possibly widely applicable in evaluating anticancer activity and metabolism of drug during the early developmental phases of natural product.

Innovation in bioanalytical strategies and in vitro drug-drug interaction study approaches in drug discovery

Failure to evaluate actual toxicities of investigational molecules in drug discovery is majorly due to inadequate evaluation of their pharmacokinetics. Limitation of conventional drug metabolism profiling procedure demands advancement of existing approaches. Various techniques such as 3D cell culture system, bio microfluidic OoC model, sandwich culture model is in pipeline to be employed at their full potential in drug discovery phase. Although they outweigh the conventional techniques in various aspects, a more detailed exploration of applicability in terms of automation and high throughput analysis is required. This review extensively discusses various ongoing innovations in bioanalytical techniques. The review also proposed various scientific strategies to be adopted for prior assessment of interaction possibilities in translational drug discovery research.

Three-dimensional hepatic lobule-like tissue constructs using cell-microcapsule technology

The proper functioning of the liver and tissues containing hepatocytes greatly depends upon the intricate organization of the cells. Consequently, controlling the shape of three-dimensional (3D) cellular constructs is an important issue for in vitro applications of fabricated artificial livers. However, the precise control of tissue shape at the microscale cannot be achieved with various commonly used 3D tissue-engineered building units, such as spheroids. Here, we present the fabrication of hepatic lobule-shaped microtissue (HLSM) containing rat liver (RLC-18) cells. By using cell-microcapsule technology, RLC-18 cells were encapsulated in the core region of poly-l-lysine-alginate microcapsules. After 14days of long-term cultivation, RLC-18 cells self-assembled into HLSM, and the cells fully occupied the microcapsule. By monitoring the cell number and albumin secretion during culture and characterizing the dimensions of the fabricated tissue, we demonstrated that the HLSM showed higher hepatic function as compared with normal cell spheroids. We also showcased the assembly of these microtissues into a 3D four-layered hepatic lobule model by a facile micromanipulation method. Our technology for fabricating 3D multilayer hepatic lobule-like, biofunctional tissue enables the precise control of tissue shape in three dimensions. Furthermore, these constructs can serve as tissue-engineered building blocks for larger organs and cellular implants in clinical treatment.

Assessment of metabolism-dependent drug efficacy and toxicity on a multilayer organs-on-a-chip

This work presents a new and multifunctional organs-on-a-chip device that allows for the characterization of the multi-step metabolism processes of pro-drug CAP in liver cells and its resultant efficacy in multiple target cells simultaneously and quantitatively.