FlowTiss: Protocol for dynamic culture of human placental villous tissue

Placental villous explants preserve the native three-dimensional architecture and cellular complexity of the human placenta but are commonly maintained under static culture conditions that do not reproduce continuous maternal-side fluid movement. FlowTiss is a reusable macrofluidic platform developed for the dynamic culture of intact human placental villous tissue. The method immobilizes villous explants by their stems while leaving the branching villous tree freely suspended and exposed to recirculating culture medium. Five explants are cultured per chamber in 8 mL medium at a controlled volumetric flow rate of 1 mL/min. Depending on the experimental design, tissue can be maintained under continuous flow for 12 h to 7 days, with 48 h representing the culture duration used during initial validation of the platform. Following culture, the freely suspended, flow-exposed tissue is separated from the mechanically immobilized region and used for downstream analyses. The setup provides sufficient tissue and conditioned medium for subsequent morphological, molecular and biochemical analyses. FlowTiss therefore provides a flexible tissue-based approach for exposing intact human placental villi to controlled dynamic culture conditions while retaining native tissue complexity and enabling a broad range of downstream applications.