Organ Model: Reproductive System

Organ Models: Vagina and cervix

Application: Microbiome

Abstract

Background: The cervicovaginal mucus that coats the upper surface of the vaginal epithelium is thought to serve as a selective barrier that helps to clear pathogens, however, its role in modulating the physiology and pathophysiology of the human vagina is poorly understood. Bacterial vaginosis (BV), a common disease of the female reproductive tract that increases susceptibility to sexually transmitted infections, pelvic inflammatory disease, infertility, preterm birth, and both maternal and neonatal infections is characterized by the presence of a wide array of strict and facultative anaerobes, often including Gardnerella vaginalis.

Objective: To assess the role of cervical mucus in preventing dysbiosis-associated complications and preserving vaginal health.

Study Design: To better understand the role of cervicovaginal mucus in vaginal health, we used human organ-on-a-chip (Organ Chip) microfluidic culture technology to analyze the effects of cervical mucus produced in a human Cervix Chip when transferred to a human Vagina Chip BV model. Both chips are lined by primary human organ-specific (cervical or vaginal) epithelium interfaced with organ-specific stromal fibroblasts.

Results: Our data show that mucus-containing effluents from Cervix Chips protect Vagina Chips from inflammation and epithelial cell injury caused by co-culture with dysbiotic microbiome containing G. vaginalis. Proteomic analysis of proteins produced by the Vagina Chip following treatment with the Cervix Chip mucus also revealed a collection of differentially abundant proteins that may contribute to the vaginal response to dysbiotic microbiome, which could represent potential diagnostic biomarkers or therapeutic targets for management of BV.

Conclusions: This study highlights the importance of cervical mucus in control of human vaginal physiology and pathophysiology, and demonstrates the potential value of Organ Chip technology for studies focused on health and diseases of the female reproductive tract.

Products Used In This Publication

Organ Model: Cervix

Application: Microbiome

To learn more about these findings, view our webinar “Organ-Chips 201: The Importance of Flow, Stretch, and Stroma for in vitro Modeling”.

How Organ-Chips Were Used: The Chip-S1 Organ-Chip consumable was used to create human Cervix-Chips, which represent physiologically relevant in vitro models to study cervix physiology and host-microbiome interactions, and hence may be used as a preclinical testbed for the development of therapeutic interventions to enhance women’s health.

Products Used In This Publication

Organ Model: Vagina

Application: Microbiome

Abstract: Women’s health, and particularly diseases of the female reproductive tract (FRT), have not received the attention they deserve, even though an unhealthy reproductive system may lead to life-threatening diseases, infertility, or adverse outcomes during pregnancy. One barrier in the field is that there has been a dearth of preclinical, experimental models that faithfully mimic the physiology and pathophysiology of the FRT. Current in vitro and animal models do not fully recapitulate the hormonal changes, microaerobic conditions, and interactions with the vaginal microbiome. The advent of Organ-on-a-Chip (Organ Chip) microfluidic culture technology that can mimic tissue-tissue interfaces, vascular perfusion, interstitial fluid flows, and the physical microenvironment of a major subunit of human organs can potentially serve as a solution to this problem. Recently, a human Vagina Chip that supports co-culture of human vaginal microbial consortia with primary human vaginal epithelium that is also interfaced with vaginal stroma and experiences dynamic fluid flow has been developed. This chip replicates the physiological responses of the human vagina to healthy and dysbiotic microbiomes. A detailed protocol for creating human Vagina Chips has been described in this article.

Featured session at Bethesda MPS Day, which took place on November 9, 2023.

Dr. Gautam Mahajan’s presentation highlights the development of a human Vagina-on-a-Chip model, enabling the study of host-microbiome interactions in the female reproductive tract with unprecedented physiological relevance. Traditional methods, such as 2D cell culture and animal models, lack the complexity and conditions needed to accurately recapitulate the vaginal environment, including hormone sensitivity, low-oxygen gradients, and dynamic microbiome communities. To address these gaps, Dr. Mahajan’s team engineered a microfluidic chip that co-cultures stratified vaginal epithelial layers with stromal fibroblasts under controlled conditions.

This human Vagina-Chip model spontaneously forms a multi-layered epithelium that mimics in vivo structure and responds to physiologically relevant hormone levels (e.g., estrogen), demonstrating the model’s functional fidelity. A key feature is the chip’s ability to sustain and study diverse vaginal microbiota. Using optimal consortia of lactobacilli, the team established conditions that maintain the low vaginal pH and produce lactic acid, reflecting a state of “optimal” (not merely “healthy”) microbiome dominance. On the other hand, introducing dysbiotic consortia (e.g., Gardnerella species) altered pH, induced epithelial cell death, and triggered proinflammatory cytokine release—hallmarks of vaginal infections such as bacterial vaginosis.

Importantly, this platform can maintain bacterial-epithelial co-cultures for up to 72 hours, surpassing limitations of simpler in vitro models. The system also allows for precise manipulation of physiological parameters (flow rates, hormone concentrations) and in-depth analysis (imaging, cytokine assays, and relative abundance of microbial species), making it suitable for investigating microbial shifts, infection mechanisms, and potential therapeutic interventions without the translational challenges posed by animal models.

Key learnings from this presentation include:

• In vivo-like structure and function: The Vagina-Chip recreates a stratified epithelium responsive to hormonal cues, oxygen gradients, and bacterial colonization.
• Support for diverse microbiota: The model can sustain both beneficial lactobacillus-dominant and dysbiotic communities, capturing clinically relevant pH changes, cellular responses, and inflammatory mediators.
• Extended culture and complexity: Unlike traditional 2D cultures, the chip supports microbiome co-culture for multiple days, enabling more realistic infection and intervention studies.
• Broad applicability: This platform may help reduce reliance on animal models, guide therapeutic development for infections (like bacterial vaginosis), and inform screening for materials and interventions relevant to women’s reproductive health.

Dr. Mahajan’s groundbreaking work has been covered by numerous publications, including the New York Times and Scientific American.

Organ Model: Vagina

Application: Microbiome

Abstract: A dominance of non-iners Lactobacillus species in the vaginal microbiome is optimal and strongly associated with gynecological and obstetric health, while the presence of diverse obligate or facultative anaerobic bacteria and a paucity in Lactobacillus species, similar to communities found in bacterial vaginosis (BV), is considered non-optimal and associated with adverse health outcomes. Various therapeutic strategies are being explored to modulate the composition of the vaginal microbiome; however, there is no human model that faithfully reproduces the vaginal epithelial microenvironment for preclinical validation of potential therapeutics or testing hypotheses about vaginal epithelium-microbiome interactions.