Assistant Professor Oregon State University Corvallis, Oregon, United States
Introduction: In the realm of feminine hygiene products, the variable amount of market regulation has recently raised concern about what qualifies as proper testing. Relevant products include tampons, liners, pads, sprays, douches, anti-itch creams, wipes, and powders. One product that has raised particular concern in recent literature is tampons. This staple of feminine hygiene, which is estimated to be used by 50-86% of women, has been found to release harmful plastic nanoparticles and per- and polyfluoroalkyl substances (PFAS). There is a significant risk that these contaminants are being released into surrounding tissues with unknown implications. Specifically, these products pose a risk to the delicate mucosal barrier, elevating the threat of infections. To bridge this knowledge gap, we are developing three-dimensional (3D) models of the vaginal mucosal epithelium to study the impacts of these contaminants on permeability and apparent diffusivity. These models can approximate the response of vaginal tissue to contaminates and create potential standards for comprehensive scrutiny and regulation within the realm of feminine hygiene products, ensuring the safeguarding of women's health and well-being.
Materials and
Methods: Primary vaginal epithelial cells (VEC) and human microvascular endothelial cells (hMVECs) are seeded in a layered three-dimensional structure composed of natural and synthetic extracellular matrix components such as: Collagen (COL) I/III, Heparin, Elastin, Lamin, Hyaluronan, Versican, Fibrinogen, Fig 1A. To evaluate the apparent role of COL I density on permeability we analyzed the diffusion of a synthetic dye through COL I hydrogels fabricated in transwells at concentrations of 2.5 and 6 mg/mL.
Results, Conclusions, and Discussions: We were able to create a standard curve of the dye, Fig. 1B, determine the absorbance values from the base well solution, Fig. 1C, and calculate the cumulative percent release of the dye from the gel, Fig 1D. In comparing the resultant apparent diffusion coefficients with those in a phosphate-buffered saline (PBS) solution. We observed an inverse correlation between collagen density and apparent diffusivity, with a 3.5-fold reduction in the diffusion coefficient at 6 mg/mL of collagen compared to PBS alone. This finding underscored the significant influence of ECM density on diffusion properties, validating our experimental approach for future investigations into drug diffusion dynamics.
From this data it can be concluded that the hydrogel composition regulates the diffusive properties of the in vitro models. Expanding on these insights, we will use our multi-layer, multicellular model of the vaginal epithelium in transwell plates to investigate the transport of potential toxins from tampons. Additionally, by calculating the apparent diffusivity and transepithelial resistance, we aim to determine how physiological changes, such as cell viability, coverage, and microvessel length, affect mucosal presence and permeability in the presence of polyethylene and PFAS. This comprehensive approach not only promises to deepen our understanding of the vaginal mucosal barrier but will also quantify the effects of feminine products contaminate the body.
