Overview

Women's health research has historically been overlooked, creating gaps where patient outcomes have been left to fall, particularly among minority groups. The 2025 BostonU iGEM team set out to join the growing group of researchers worldwide working to address these gaps and improve women's healthcare. Our research contributes to this effort by enabling future iGEM teams and other researchers to build on three key developments: a platform for testing vaginal swab samples using whole-cell biosensors, a new framework for integrating human practices feedback, and new parts for detecting bacterial vaginosis (BV) biomarkers and interfacing with our custom hardware.

A platform for testing vaginal swab samples

The vaginal microbiome is a diverse and dynamic microenvironment that varies widely from person to person. Because of this, we identified a need for better temporal resolution in vaginal microbiome health diagnostics, particularly concerning bacterial vaginosis. By looking at a patient over time, we can get a better understanding of their unique microbiome and what an unhealthy state might look like for that individual. Current diagnostics for bacterial vaginosis require in-person clinic visits or lab testing which cause friction and often have long turnaround times. This motivated our design of an at-home testing platform for vaginal swabs.

Building on the work of BostonU iGEM 2024, we sought to expand the possibilities of deployable whole-cell biosensor technology through an integrated hardware and biology platform. We started with rebuilding and improving upon the excitation/emission optics hardware from BostonU iGEM 2024. In doing so, our device enables relatively low-cost fluorescence detection in an at-home form factor.

For biosensor deployment, we evaluated the efficacy of agar hydrogels for E. coli biosensor longevity and responsivity. Our testing showed that E. coli producing eGFP under a constitutive promoter maintained expression after one week, meeting our target for initial testing. By combining a mobile fluorescence detection system and hydrogel-embedded biosensors, this work demonstrates a workable platform for at-home biosensor deployment.

Applying our deployable fluorescence detection setup to the problem of BV diagnostics, we designed and built a mechanism for vaginal swab sample testing. Our hardware enables consistent, standardized sample collection from vaginal swabs. Currently, our internal control monitors biosensor activity for better signal normalization. In the future, more internal standard controls could be implemented to ensure proper sample collection and normalization.

By laying the groundwork for at-home vaginal microbiome analysis, we hope to enable new research opportunities in women’s health. Using our low-cost open source hardware, future iGEM teams can build on our platform to study the vaginal microbiome further. Our research and conversations with experts made it clear that more data is needed to enable further improvements in our understanding of the vaginal microbiome. This platform makes that possible.

A framework for human practices integration

Recognizing that inadequate stakeholder engagement has been a key downfall of previous research efforts in women’s health, our team sought a rigorous method for feedback collection from the beginning. We developed and utilized the Observe, Ask, Implement (OAI) cycle—a systematic framework to capture diverse perspectives throughout the design process. This approach begins with observing current practices and identifying knowledge gaps, proceeds to actively soliciting input from experts, stakeholders, and end users, and concludes with implementing design modifications based on this feedback. The key is that this process is iterative, allowing us to continually improve our device and incorporate feedback as the project progresses. Through this method, we ensured that our platform development remained responsive to the needs and concerns of users, researchers, and other stakeholders. This framework not only strengthened our project, but also provided a replicable model for future projects seeking to methodically integrate human practices feedback. The systematic nature of OAI helps us move beyond token consultation toward meaningful collaboration with the communities our work aims to serve.

New Parts

To monitor bacterial vaginosis using whole-cells biosensors, we focused on putrescine as a biomarker of vaginal dysbiosis. We adapted the putrescine sensing circuit from Selim et al., (1) bringing the PuuR repressor protein into the iGEM parts registry. (See our part here. Part Number: BBa_25087KBX )

PuuR is a repressor protein that binds to the PuuO operator sequence. Selim et al. (1) generated synthetic promoters utilizing this operator sequence and we adapted one for this work. We characterized the response of the repressor protein using eGFP as a reporter and mCherry as an internal control (Figure 1).

The PuuO operator sequence is contained within the pHyb(1B) promoter, allowing PuuR to bind. PuuR is under the control of the constitutive T7 promoter for expression in BL21(DE3) E. coli. mCherry is an internal control reporter and eGFP is the circuit reporter.

Using this part, future teams can now sense and respond to the biogenic amine putrescine. The PuuR-responsive promoter, pHyb(1B) from Selim et al.(1), has also been turned into a basic part that can work in tandem with PuuR for building circuit logic. Our full expression testing cassette is also available as a composite part for other teams to build off.