Regenerating re-absorption function of proximal convoluted tubule using microfluidics for kidney-on-chip applications

Abstract

Human kidney is a sophisticated organ with 1 Million nephrons arranged in subtle form. Kidney has the most failure cases in the world compared to the rest of the body organs. Kidney failure is a severe problem, where cardiac blood output is not filtered. Dialysis is one available substitute for kidney failure, which seems to help the patient incompletely. There is a great necessity for a device (artificial kidney) that can be implanted into the body to resume the kidney function. In replicating kidney function there are many potential challenges, which must be addressed for faithful regeneration. This paper primarily focuses on regenerating the proximal convoluted tubule (PCT) size dependent re-absorption, mimicking this function using microfluidics is not reported earlier. Different structural changes in the design have been adopted and the accomplishments are discussed. It is observed that the total flow (the total of flow through all 1000 channels) in straight is 0.4 × 10−16 m3/s, in the diagonal channel is 0.4 × 10−16 m3/s, in step is 0.32 × 10−16 m3/s and in serpentine is 0.38 × 10−16 m3/s. The size-dependent re-absorption of solutes, proteins, and urea with the help of array of channels has been achieved. The dimensions of the main tubule and channel are selected to replicate cell–cell interactions. The re-absorption rate obtained is around 48%, which is closely reaching the PCT re-absorption rate. The increase in the number of channels shows increase in re-absorption rate. The novelty of reported work lies in regenerating the human kidney proximal tubule cell function of size and shape dependent re-absorption using microfluidics technology. The proposed device performance proves its prevalence in kidney-on-chip applications.