Vaginal Cervical Decidual Fetal-Maternal Interface Organ-on-Chip (VCD-FMi-OOC) Model for Analyzing the Ascension of the Pathological Core of Bacterial Vaginosis to the Maternal-Fetal Interface during Metronidazole Treatment

• Grant number: 24/17377-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2025
• End date: December 31, 2027
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Márcia Guimarães da Silva
• Grantee: Mariana de Castro Silva
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 24/07342-9 - Organ-on-chip traffic dynamics of bacterial vaginosis-associated bacteria in the genital tract, gestational tissues, and induction of compartmentalized inflammatory response., AP.R

Abstract

Introduction: The microbiota of the female reproductive tract as a whole, especially the vaginal microbiota, plays a critical protective role in women's reproductive health by maintaining vaginal health and consequently reducing vulnerability to sexually transmitted infections (STIs). Bacterial vaginosis (BV) is the main dysbiosis affecting women of reproductive age, being associated with an increased risk of acquiring STIs as well as leading to adverse pregnancy outcomes. In vivo and in vitro models used to study these interactions have limitations in terms of representativeness and ethics, highlighting the importance of alternative models, such as organ-on-chip, to better mimic human physiology and investigate bacterial ascension and the inflammatory response associated with BV in pregnant women. These models also emerge as tools for pharmacological testing. Objective: To mimic the polymicrobial environment of bacterial vaginosis in an organ-on-chip device integrating vaginal, cervical, and decidual cell types (VCD-OOC), as well as chorioamniotic membranes (FMi-OOC), for the analysis of the ascension of the pathological core of bacterial vaginosis to the maternal-fetal interface during Metronidazole treatment. Methods: Organ-on-chip devices integrating VCD-OOC and FMi-OOC will be employed as a model for studying polymicrobial infection of the amniotic cavity and the cytotoxic and inflammatory effects of Metronidazole. The analysis of bacterial and Metronidazole diffusion will be conducted in the devices, with monitoring via fluorescence microscopy and flow cytometry. To assess the effects of bacterial stimuli and Metronidazole treatment, lactate dehydrogenase cytotoxicity assays and bacterial count by flow cytometry will be performed. To analyze the inflammatory profile, a LUMINEX assay will be conducted for mediators of the innate immune response (IL-1¿, IL-6, sIL-6R, sgp130, mIL-6R, gp130, IL-8, IL-10, IL-13, TNF-¿, GM-CSF). The data obtained will be subjected to statistical analysis, and the choice of comparative tests will consider the assumptions determined by the results, characteristics, and behaviors of the study variables. A significance level of 5% will be adopted for all tests.