Scalable hydrogel platform reveals mechanosensitive modulation of oxytocin-induced calcium responses in myometrial cells.

Both preterm labor and postpartum hemorrhage (PPH) are critical pregnancy complications driven by dysfunctional uterine contractions. Current therapeutics for myometrial contractile modulation are largely ineffective and nonspecific, partly due to a poor understanding of the complex interplay between biochemical and biomechanical cues in the myometrial microenvironment. Specifically, the influence of matrix stiffness on myometrial cell behavior and agonist responses, like those to oxytocin, remains underexplored, hindering the development of targeted interventions. This significant gap necessitates physiologically relevant research tools to advance understanding of myometrial physiology.

Researchers developed a scalable in vitro polyacrylamide hydrogel platform directly fabricated in multiwell plates and Petri dishes. They validated its mechanical properties as a tunable cell culture substrate, mimicking physiological, pathological, and supraphysiological uterine stiffness conditions. Using a fluorescent calcium mobilization assay in a plate-reader-based workflow, they assessed the dose sensitivity of myometrial cells to oxytocin and measured stiffness-mediated effects on agonist-induced calcium responses. Myometrial cell behavior on these tunable substrates was then compared against standard tissue culture plastic.

The study successfully validated the polyacrylamide hydrogel platform as a mechanically tunable substrate for myometrial cell culture. They observed a clear mechanosensitive modulation of calcium response curve amplitude in myometrial cells stimulated with oxytocin, indicating that substrate stiffness directly influences the cells' contractile signaling. This mechanosensitivity was evident across a range of elastic moduli, demonstrating that both physiological and pathological stiffness conditions can influence the cellular response to endogenous agonists. The findings suggest that the mechanical properties of the uterine matrix are critical determinants of myometrial contractility, influencing how cells perceive and respond to biochemical cues like oxytocin. Myometrial cells cultured on physiologically relevant hydrogel stiffnesses exhibited significantly altered morphology and calcium responses compared to those on supraphysiological tissue culture plastic, underscoring the profound impact of the mechanical microenvironment. > The observed changes to myometrial cell morphology and calcium responses highlight the significant influence of supraphysiological substrates, such as standard tissue culture plastic, on experimental outcomes.