The Role of Microfluidics for Organ on Chip Simulations

Abstract

A multichannel three-dimensional chip of a microfluidic cell culture which enables the simulation of organs is called an "organ on a chip" (OC). With the integration of many other technologies, OCs have been mimicking organs, substituting animal models, and diminishing the time and cost of experiments which is better than the preceding conventional in vitro models, which make them imperative tools for finding functional properties, pathological states, and developmental studies of organs. In this review, recent progress regarding microfluidic devices and their applications in cell cultures is discussed to explain the advantages and limitations of these systems. Microfluidics is not a solution but only an approach to create a controlled environment, however, other supporting technologies are needed, depending upon what is intended to be achieved. Microfluidic platforms can be integrated with additional technologies to enhance the organ on chip simulations. Besides, new directions and areas are mentioned for interested researchers in this field, and future challenges regarding the simulation of OCs are also discussed, which will make microfluidics more accurate and beneficial for biological applications.

Keywords: 3D biopringting; Bioengineering; Biosensors; Microbiome; Microfluidics.

Figure 1

Heart on a chip [23]: (a) Scheme of the fabrication process; (b) Assembly of the microfluidic device, consisting of an aluminum bottom, a recess for holding the chip, polycarbonate top held by three screws, and barbed fittings with fluidic tubes for fluidic input/output.

Figure 2

Liver on a chip [79] with cell culture: Red colour represents the hepatocytes, gray colour represents the endothelium like gaps, and yellow colour represents the medium. Channels are separated with microfabricated barriers for the separation of hepatocytes from fluid.

Figure 3

Bone on a chip [83]: Polydimethylsiloxane (PDMS) device with cylindrical cavity filled with induced bone material (open at either ends or closed at one end) is to form engineered bone marrow (eBM) in vivo for 8 weeks and then this eBM is cultured in a microfluidic device. The green and blue channels are medium perfusion channels for maintaining the eBM in the central chamber.

Figure 4

Gut on a chip [21]: (a) Gut on a chip device showing an extra cellular matrix (ECM) coated flexible porous membrane with gut epithelial cells through the middle of the central microchannel and vacuum chambers on both sides; (b) An image of the gut on a chip device. Syringe pumps are used to perfuse the blue and red dyes (directions indicated by arrows) to visualize these channels.