Non-invasive Biomechanical Characterization of Embryos Using Microfluidic Cantilevers

Abstract

Embryonic development is intricately regulated by mechanical properties such as stiffness, which influence developmental viability and implantation success - factors critical in assisted reproductive technologies (ART). Traditional embryo evaluation relies predominantly on morphology, lacking quantitative mechanical parameters that could enhance selection accuracy. Recent studies indicate that the stiffness (elasticity) of the zona pellucida (ZP) - the glycoprotein-rich extracellular matrix surrounding mammalian oocytes and embryos - correlates with embryo quality and developmental potential. However, current biomechanical characterization techniques - including micropipette aspiration, atomic force microscopy (AFM), microtactile sensors, and MEMS-based systems - either pose risks of mechanical damage or involve complex, time-consuming procedures unsuitable for clinical settings. Here, we introduce a novel approach leveraging fluidic force microscopy cantilevers to non-invasively evaluate embryo biomechanics. Our proof-of-concept study demonstrates rapid, precise stiffness profiling of intact mouse embryos (specifically ZP elasticity) in under one minute per embryo. Using gentle microsuction attachment with no chemical adhesives or rigid immobilization, the method preserves embryo integrity while providing reproducible elasticity measurements. This method combines the precision of AFM with minimal invasiveness, offering a promising new quantitative biomechanical indicator to augment clinical embryo assessment and paving the way for broader applications in reproductive biology.