In vitro M‐like cells genesis through a tissue‐engineered triple‐culture intestinal model

Abstract Although fewer in number, M‐cells are considered antigen sampling cells, acting as a gateway for antigens from the gut lumen and presenting an impressive aptitude for particle transcytosis. These features make M‐cells attractive targets for oral drug delivery studies, but this has been poorly explored. New and reproducible tissue‐like in vitro models for studying intestinal sampling and permeability mechanisms are needed. The combination of different cell players in such models offers improved microenvironments with higher physiologic relevance. Here, a tissue‐engineered model was established, by co‐culturing Caco‐2 absorptive cells, HT29‐MTX mucus‐producing cells and Raji B lymphocytes. After 3 weeks of cell co‐culture, the presence of M‐like cells was evidenced by the loss of brush‐border organization, detected by the lack of microvilli. The triple‐culture model showed to be efficient for insulin transport, a process that was influenced by the tightness of junctions between epithelial cells and the presence of mucus and M‐like cells. Ultimately, the proposed tissue‐engineered model provides a more complete and reliable tool to perform drug permeability tests, as compared to traditional models, and may also find applicability as an in vitro system to study transdifferentiation mechanisms of M cells. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 104B:782–788, 2016.