Overview

We are a group of 17 high school students passionate about biology, and this year, we formed the iGEM team BGI-MammothEdu-East. Our project, Scentinel: Fragrance for Empowerment, leverages synthetic biology to empower visually impaired women by helping them manage their menstrual cycles using bioengineered fragrance compounds. We aim to develop a material that, when integrated into sanitary pads and laundry detergents, releases specific scents when in contact with menstrual blood or secretions. These scent signals will allow visually impaired women to autonomously track their menstrual cycle, ensuring dignity and confidence in their day-to-day lives.

Over the course of our eight-month project journey, we’ve gained a deep understanding of the needs of visually impaired women through comprehensive human practices activities. By engaging with this often-overlooked group, we learned about their challenges, heard their concerns, and tailored our solution accordingly. Our project also brought blind participants into the lab to experience the power of synthetic biology firsthand, fostering greater awareness of science within this community.

In terms of technical progress, we have tested the synthetic biology production of seven terpenoids, including limonene, ocimene, cineole, nerolidol, nerol, borneol and myrcene. We successfully constructed expression vectors for all seven compounds. Four of these compounds (ocimene, cineole, nerolidol, and nerol) have been biosynthesized using yeast fermentation, with their production confirmed via gas chromatography–mass spectrometry.

Inspiration

The inspiration for our project came from that our team member Jiatong Zhang noticed a viral article on Chinese social media XiaoHongShu about the struggles of visually impaired women, particularly with managing their menstrual cycles. Through brainstorming and literature research, we recognized the significance of this issue. Women with visual impairments face unique challenges in managing their periods, as they cannot visually determine when their menstruation begins, ends, or when to change sanitary products. This often leads to discomfort, inconvenience, and embarrassment.

This realization motivated us to leverage synthetic biology to address these challenges with empathy and innovation. We also recognized that individuals with impaired vision might have a heightened sense of smell, which opened the possibility of using fragrances as a signaling mechanism in their daily lives. Through our interviews with visually impaired women, we confirmed the reality of these challenges, further validating our project’s direction.

Additionally, we were inspired by prior iGEM projects, such as those from Toulouse_INSA-UPS(2020) and BASIS-China(2023), which demonstrated the potential of using synthetic biology to produce fragrance compounds, traditionally extracted from plants. With this inspiration, we set out to select and synthesize pleasant-smelling, distinctive, and safe compounds that could serve as olfactory signals. The selected terpenoids also have antibacterial properties, adding a functional benefit beyond their fragrance.

Our Solution and Products

Currently, there are no products specifically designed to help visually impaired women manage their menstrual cycles. Existing sanitary products and apps rely on visual input, making them unsuitable for this demographic. While scented sanitary pads exist, they do not offer any functional benefit in detecting menstrual cycle changes. We drew inspiration from color-changing diapers that notify parents when a diaper needs changing and sought to develop a scent-based solution for blind women.

Scentinel fills this gap. We are creating a unique product that integrates bioengineered fragrance compounds into sanitary pads and laundry detergents. The core of our innovation lies in scent-releasing materials that dissolve upon contact with menstrual blood, triggering the release of fragrances that act as sensory signals. These signals help visually impaired women manage their periods by indicating:

1. The start of menstruation
2. When to change sanitary products (due to fullness or leakage)
3. When menstruation ends

Our encapsulated scent-releasing material will be embedded into sanitary pads and undergarments via laundry detergents, providing comprehensive and discreet menstrual cycle management.

Comparison Table

Product	Function	Limitation for Visually Impaired Women
Traditional Sanitary Pads	Absorb menstrual blood	No indicators for start, change, or end of period
Period Tracking Apps	Track cycle timing	Requires manual input, inaccessible without vision
Scentinel	Tracks cycle via scent	Sensory signals independent of vision, comprehensive cycle management

What Have We Done?

Our team has made significant progress toward realizing Scentinel:

• Biosynthesis of Fragrance Compounds: We have successfully engineered Saccharomyces cerevisiae to biosynthesize seven key terpenoids: limonene, ocimene, cineole, borneol, myrcene, nerolidol, and nerol. Expression vectors were successfully constructed for all seven compounds, and four (ocimene, cineole, nerolidol, and nerol) have already been produced through yeast fermentation and validated through gas chromatography–mass spectrometry.
• Encapsulation Techniques: We designed encapsulation methods to preserve these compounds and ensure their controlled release when in contact with menstrual fluids. We are planning to test materials for encapsulation, considering reverse osmosis membranes and other potential options based on expert input.
• Product Prototypes: Our product designs include sanitary pads with scent-releasing materials in their wings, providing a dual benefit of leakage prevention and timely reminders. We are also working on developing laundry detergents with encapsulated fragrance compounds that infuse into undergarments, offering long-lasting scent signals throughout the menstrual cycle.
• Human Practices and Modeling: Through interviews with visually impaired women, we confirmed the real-world applicability of our solution. We also consulted material science experts on the best encapsulation materials for our design. Additionally, we conducted computational modeling to predict the growth curve of yeast when expressing foreign genes for fragrance production and to optimize the diffusion and dosage of the fragrance compounds for effective signaling.
• Market Analysis: We have begun analyzing market demand, assessing the needs of our target user group, and evaluating the competitive landscape of menstrual hygiene products. Our product fills a critical gap in the market, offering both practical and emotional benefits to visually impaired women.
• Inclusivity and Engagement with Visually Impaired Communities: Our project is not only centered on addressing the challenges faced by visually impaired women but also actively promotes inclusivity in science. We conducted thorough research into the barriers visually impaired individuals face in engaging with synthetic biology and scientific activities. To raise awareness of synthetic biology, we organized outreach efforts tailored to the blind community, engaging them directly in multiple conversations. By listening to their feedback, we were able to adjust our project design and ensure it better aligned with their needs and preferences.

Summary and Perspectives

Scentinel: Fragrance for Empowerment offers a revolutionary solution for visually impaired women to manage their menstrual cycles autonomously. By harnessing the power of synthetic biology and fragrance engineering, we are addressing an overlooked issue with empathy and innovation. Our product provides a practical, scent-based solution that promotes independence and dignity for women who rely on non-visual cues. With further development and optimization, Scentinel has the potential to make a lasting impact on the menstrual health and well-being of blind women worldwide.

Reference

[1] Menstrual Matters: https://www.menstrual-matters.com/visual-impairment

[2] Toulouse_INSA-UPS(2020): https://2021.igem.org/Team:Toulouse_INSA-UPS

[3] BASIS-China(2023): https://2023.igem.wiki/basis-china/

[4] Li, D.-X., Q. Guo, Y.-X. Yang, S.-J. Jiang, X.-J. Ji, C. Ye, Y.-T. Wang and T.-Q. Shi (2024). "Recent Advances and Multiple Strategies of Monoterpenoid Overproduction in Saccharomyces cerevisiae and Yarrowia lipolytica." ACS Synthetic Biology.

[5] Green, S. A., X. Chen, N. J. Nieuwenhuizen, A. J. Matich, M. Y. Wang, B. J. Bunn, Y.-K. Yauk and R. G. Atkinson (2011). "Identification, functional characterization, and regulation of the enzyme responsible for floral (E)-nerolidol biosynthesis in kiwifruit (Actinidia chinensis)." Journal of Experimental Botany 63(5): 1951-1967.

[6] Kampranis, S. C., D. Ioannidis, A. Purvis, W. Mahrez, E. Ninga, N. A. Katerelos, S. Anssour, J. M. Dunwell, J. r. Degenhardt, A. M. Makris, P. W. Goodenough and C. B. Johnson (2007). "Rational Conversion of Substrate and Product Specificity in a Salvia Monoterpene Synthase: Structural Insights into the Evolution of Terpene Synthase Function." The Plant Cell 19(6): 1994-2005.

[7] Kong, X., Y. Wu, W. Yu, Y. Liu, J. Li, G. Du, X. Lv and L. Liu (2023). "Efficient Synthesis of Limonene in Saccharomyces cerevisiae Using Combinatorial Metabolic Engineering Strategies." Journal of Agricultural and Food Chemistry 71(20): 7752-7764.

[8] Li, R., B. Yao and H. Zeng (2024). "Identification and Characterization of a Nerol Synthase in Fungi." Journal of Agricultural and Food Chemistry 72(1): 416-423.