Preparation, characterization, and transport of dexamethasone-loaded polymeric nanoparticles across a human placental in vitro model

Abstract

The purpose of this study was to prepare dexamethasone-loaded polymeric nanoparticles and evaluate their potential for transport across human placenta. Statistical modeling and factorial design was applied to investigate the influence of process parameters on the following nanoparticle characteristics: particle size, polydispersity index, zeta potential, and drug encapsulation efficiency. Dexamethasone and nanoparticle transport was subsequently investigated using the BeWo b30 cell line, an in vitro model of human placental trophoblast cells, which represent the rate-limiting barrier for maternal-fetal transfer. Encapsulation efficiency and drug transport were determined using a validated high performance liquid chromatography method. Nanoparticle morphology and drug encapsulation were further characterized by cryo-transmission electron microscopy and X-ray diffraction, respectively. Nanoparticles prepared from poly(lactic-co-glycolic acid) were spherical, with particle sizes ranging from 140–298 nm, and encapsulation efficiency ranging from 52–89%. Nanoencapsulation enhanced the apparent permeability of dexamethasone from the maternal compartment to the fetal compartment more than 10-fold in this model. Particle size was shown to be inversely correlated with drug and nanoparticle permeability, as confirmed with fluorescently-labeled nanoparticles. These results highlight the feasibility of designing nanoparticles capable of delivering medication to the fetus, in particular, potential dexamethasone therapy for the prenatal treatment of congenital adrenal hyperplasia.

Transport of digoxin-loaded polymeric nanoparticles across BeWo cells, an in vitro model of human placental trophoblast

“…We hypothesized that the nanoparticles may result in increased transfer of digoxin across trophoblast cells by reducing the interaction of the drug from the efflux transporter P-gp. Each nanoparticle carries multiple drug molecules into and across the trophoblast cell barrier (the translocation of fluorescent PLGA nanoparticles across BeWo cell monolayers has been demonstrated previously [20]). Drug molecules encapsulated within the nanoparticles could be shielded from interaction with P-gp as they are delivered across the trophoblast cells.…”

“…future science group Transport of digoxin-loaded polymeric nanoparticles across BeWo cells Research Article sulation efficiency was calculated as described previously [20], with correction for any nonspecific binding of digoxin to the filter membranes. Details regarding the equations relating drug loading and encapsulation efficiency have been published previously [21].…”

“…No endotoxin contamination was expected as all studies were conducted under sterile conditions and the cell culture medium components were already tested for endotoxin contamination. A continuous trophoblast layer is important in the protective function of the placenta [26], and therefore, transepithelial e lectrical resistance (TEER) measurements were used to measure the integrity of cell monolayers [20]. TEER values were measured using an EndOhm ® voltohmmeter (World Precision Instruments, FL, USA), at 25°C starting on day 4 post seeding to ensure monolayer formation.…”

“…These ranges of TEER values are the same which resulted in strong comparisons of transplacental permeability measured by both BeWo cell transport studies and ex vivo placental perfusions [15,29]. Ali et al utilized BeWo b30 cells with similar TEER values and demonstrated an inverse relationship between TEER values and the permeability of the paracellular marker Lucifer yellow, which provides confidence of monolayer formation appropriate for transport studies when TEER values are in this range [20].…”

Studying nanoparticle interaction with human placenta: Festina lente!

“…Poulsen et al, 2015), but even more studies using only a single monolayer of choriocarcinoma cells like BeWo on a crude collagen matrix (e.g. Correia Carreira et al, 2015 or Ali et al, 2013), do not explain much about nano biokinetics in early human gestation (Juch et al, 2013). Especially, the critical period of organogenesis, when severe malformations can be induced, is not represented by such experiments, an essential teratologic issue worth mentioning in the discussions.…”