3D bioprinted placenta-on-a-chip platform for modeling the human maternal–fetal barrier

The placenta plays a vital role in pregnancy by regulating selective exchange between maternal and fetal circulations and producing essential hormonal signals. Here, we present an in vitro placenta-on-a-chip platform that leverages 3D bioprinting to replicate the structural and functional features of the human placental barrier. This microengineered system utilizes digital light processing 3D bioprinting to fabricate the microfluidic mold and to construct 3D encapsulated cell cultures within a biomimetic hydrogel scaffold, enabling co-culture of three human cell types, including two derived from primary placental tissue. We demonstrate excellent cell viability, high metabolic activity, placental hormone secretion, and native-like selective barrier transport properties within the model. This system offers a versatile platform for experimental perturbations to explore mechanisms of normal placental function and identify contributors to placental dysfunction.