Serum-reduced and serum-free media for differentiation of Caco-2 cells.

Human intestinal Caco-2 cells were differentiated using serum-reduced medium with fetal bovine serum (FBS) added only to the basolateral (BL) medium, and four serum-free media, containing insulin, transferrin, selenium (ITS), or MITO+™ serum extender (ITS plus growth factors), with or without addition of a lipid mixture, respectively. Differentiation was assessed by monitoring monolayer permeability, alkaline phosphatase and sucrase activities, and the transport of digoxin and cephalexin. Notably, the serum-reduced protocol produced results that were comparable to cells differentiated in the control medium and should be recommended as an alternative to the use of 10% FBS in both apical (AP) and BL media. ITS serum-free medium elicited permeability values and cephalexin transport similar to control cells. MITO+™ medium was the most efficient in promoting the two transport activities investigated, and it should be further evaluated with a larger set of substances, although its undisclosed composition represents a limit that may override these advantages.