Figure 1.

Human kidney proximal tubule Tissue-on-a-Chip model: (a) Schematic representation of the nephron and where the kidney tubule chip fits. Perfusion and injection ports are shown and referenced to in Materials and Methods. Each chip represents a segment of a single proximal tubule, with the extrapolation between them conducted using the physiologically-based model in (b). (b) Physiologically-based model for renal clearance including a physical tubular reabsorption model. The “tubule” portion of this model corresponds to either the in vivo tubule or the portion of the “chip” where an in vitro tubule is formed. The remainder of the model is only applicable in vivo. Physical dimensions and other parameters for the human proximal tubule and the kidney tubule chip are described in the text.