TABLE 1.

Kidney 3D culture models.

	Organoids	Microphysiological systems (MPS)
Advantages	• Derived from human pluripotent stem cells (hPSCs) allowing models of disease states and genetic variability	• Engineered microchips with primary human kidney cells to mimic kidney functions
	• Contains more than 1 cell type allowing simultaneous toxicity screenings of multiple cell types	• Recapitulate fluid shear stress and mechanical strain
	• Recapitulates interactions between different cell types present in the system	• Media to cell ratios approximate physiological values
	• Cells maintain proper gene expression and phenotypes longer than traditional 2D cultures, allowing for longer treatments and studies	• Under consideration by pharmaceutical industry and regulatory agencies
	• Ability to respond to stress by expressing and/or releasing injury markers in specific cell types
	• Can be automated allowing for higher-throughput screening
Disadvantages	• Lack of vascularization	• Inconsistent reproducibility due to variability from both donors and suppliers
	• Lacks physiologically relevant components such as fluid flow	• Lack of standardized kidney chip format allows more variability
	• Limited ability to grow and mature	• The majority of reported kidney MPS models are limited to PTECs
	• Differences in hPSC sources and differentiation protocols could lead to batch-to-batch variability, affecting experimental reproducibility	• High cost of a single MPS platform
		• Potential adsorption of test agents by PDMS in many systems
		• In vitro-in vivo translation requires optimization in multi MPS scaling
Culture time	• Slower (weeks to months) to establish due to lengthy hPSC induction	• Faster (days to weeks)