Recent clinical success of nucleic acid loaded lipid nanoparticles (LNPs) is paving the way for their use in numerous healthcare applications, including the delivery of therapeutics to advance prenatal and women’s health. The limited information on pharmaceutical interactions during pregnancy drives the need for research on how drug and gene delivery vehicles interact with the placental barrier for the development of therapies for pregnancy-related complications. Three main types of trophoblast cells comprise the placenta: cytotrophoblast, extravillous trophoblast, and syncytiotrophoblast cells, each with their own distinct functions contributing to a healthy pregnancy. This study aims to compare ionizable lipids that have been used in FDA-approved formulations for nucleic acid delivery to placental trophoblast cells and evaluate the effects of trophoblast cell behavior on transfection efficiency. LNPs are most notably used for the delivery of nucleic acids in the COVID-19 vaccines, as well as in a therapeutic for polyneuropathy. In this study, LNPs were formulated with ionizable lipids, helper lipids, cholesterol, and polyethylene glycol-conjugated lipids through microfluidic mixing. These LNP formulations incorporated either ALC-0315, Dlin-MC3-DMA (MC3), or SM-102 ionizable lipids. All LNPs were loaded with luciferase-producing messenger RNA (mRNA). Physicochemical properties of LNPs were measured and found to have uniform size distributions with an average diameter of 86.5 nm, neutral zeta potential, and encapsulation efficiency of mRNA > 85%. To measure their uptake and gene expression across different placental trophoblast cell types, HTR-8/SVneo extravillous trophoblast cells, BeWo b30 choriocarcinoma cells which are commonly used for cell monolayer transport studies, and primary human placental stem cells were used in transfection studies. Results demonstrated that all LNPs had successful uptake and subsequent gene expression by all trophoblast cell types. The SM-102 formulation resulted in ~10-fold increased gene expression compared to the formulations containing ALC-0315 and MC3 in HTR-8/SVneo cells. Similar trends were observed across all placental cell types studied, with comparable expression between immortalized and primary stem cells. Green fluorescent protein (GFP)-tagged mRNA loaded LNPs were formulated and characterized to confirm luciferase results. These results are an initial step to designing delivery vehicles for therapeutics to treat pregnancy-related complications.
