BME PhD Dissertation Defense: Isabella Claure

Title: “Interrogating mechanosensitive modulation of contractile behavior in the pregnant myometrium”

Advisory Committee: Joyce Y. Wong, PhD – BME, MSE (Co-Research Advisor) Catherine M. Klapperich, PhD- BME, MSE, ME (Co-Research Advisor) Michael Smith PhD- BME (Chair) Wendy Kuohung, MD – BU Obstetrics and Gynecology Matthew Layne, PhD – BU Biochemistry and Cell Biology

Abstract: In pregnancy, contraction of the uterine muscle layer known as the myometrium plays a determinant role in both maternal and fetal outcomes. Premature or insufficient activation of contractile pathways result in major obstetric complications like preterm labor and post-partum hemorrhaging, respectively. Clinical interventions rely on contractile modulators that halt or induce contractions, but presently available therapeutics report limited effectiveness and off-target side effects. Advancing the therapeutic landscape requires identifying the underlying mechanisms of abnormal labors, however contractile regulation in the pregnant myometrium is a complex interplay of microenvironmental cues that is not well-defined. For example, uterine pathologies that alter myometrial tissue properties like uterine fibroids and adenomyosis increase the risk of obstetric complications, but there is limited research assessing the effects of mechanobiological interactions on myometrial cell behavior. Engineered hydrogel microenvironments address knowledge gaps in myometrial mechanobiology through in vitro recapitulation of physiological and pathological matrix properties including stiffness, composition, and organization. In vitro hydrogel platforms offer greater control over the cellular microenvironment than traditional in vitro and ex vivo model systems, but existing fabrication approaches are unable to increase throughput and yield without becoming costly or labor-intensive. In this work, we developed a scalable liquid-based technique for synthetic hydrogel fabrication directly in multiwell plates and petri dishes. To apply this approach to myometrial mechanobiology, we successfully fabricated polyacrylamide hydrogels of distinct moduli in 96 well plates and validated a plate-reader based assessment of agonist-mediated calcium responses in myometrial cells. Utilizing our in vitro hydrogel platform, we identified stiffness-mediated effects on myometrial cell morphology and oxytocin-mediated calcium responses. Lastly, we explored how pathological microenvironments intersect with mechanosensitive contractile pathways to influence myometrial cell behavior. Together, this work opened new opportunities in myometrial mechanobiology with scalable fabrication of a high throughput in vitro hydrogel platform to identify mechanosensitive contractile modulators.