There isn't one specific final concentration to be used for such an application. It is advised to refer to scientific literature for more details on experimental setup. Below is a citation of an article that could be of potential interest.
't Hart DC, Yildiz D, Palacio-Castañeda V, Li L, Gumuscu B, Brock R, Verdurmen WPR, van der Vlag J, Nijenhuis T. Co-Culture of Glomerular Endothelial Cells and Podocytes in a Custom-Designed Glomerulus-on-a-Chip Model Improves the Filtration Barrier Integrity and Affects the Glomerular Cell Phenotype. Biosensors (Basel). 2023 Mar 3;13(3):339. doi: 10.3390/bios13030339. PMID: 36979551; PMCID: PMC10046631.