The placenta serves as the interface between the maternal and fetal circulations and regulates the transfer of oxygen, nutrients, and waste products. When exogenous substances are present in the maternal bloodstream—whether from environmental contact, occupational exposure, medication, or drug abuse—the extent to which this exposure affects the fetus is determined by transport and biotransformation processes in the placental barrier. Advances in drug delivery strategies are expected to improve the treatment of maternal and fetal diseases encountered during pregnancy.

This chapter provides an overview of cell culture models that may be used to predict drug transport across relevant biological barriers. General considerations regarding the utility of such a model are discussed, followed by a brief description of physiological cell barrier properties and cell culture models that have been utilized or proposed to understand mechanisms of drug transport in the intestinal epithelium, the blood–brain barrier (BBB), nasal and pulmonary epithelium, ocular epithelial and endothelial barriers, the placenta, and renal epithelium.

Background: Fetal arrhythmias can lead to fetal congestive heart failure and hydrops fetalis. Digoxin (the first-line treatment) has low transplacental permeability and high risk of maternal side effects. Biodegradable digoxin-loaded PEGylated poly(lactic-co-glycolic acid) nanoparticles may increase digoxin transport across BeWo b30 cell monolayers (an in vitro model of trophoblast in human placenta) by reducing the drug's interaction with P-gp. Results/methodology: The nanoparticles showed high encapsulation efficiency and sustained release over 48 h.