Description
Human neural morphogenesis is a fundamental process of embryonic development that guides the formation of the central nervous system. It originates from an elongated structure called neural tube, which regionalizes and patterns giving rise to distinct neuronal identities spatially organized along its two main axes (antero-posterior and dorso-ventral). Neural tube patterning is regulated by multiple intrinsic and extrinsic factors acting through a coordinated cross-talk between biochemical and biophysical signals. Gradients of signalling molecules known as morphogens, secreted by surrounding tissues, provide spatial information along the major developmental axes. In addition to biochemical cues, cell behaviour is strongly influenced by biophysical signals arising from the local microenvironment. Extracellular matrix (ECM) properties and mechanosensing have a central role during the earliest stages of human neural development; however, how developing neural tissues integrate mechanical cues with morphogen-driven signalling to coordinate cell fate specification, spatial patterning, growth, and morphogenesis remains poorly understood.
Due to ethical constraints and limited experimental accessibility, direct investigation of early human neural development is not feasible in vivo, underscoring the need for physiologically relevant human in vitro models. Human pluripotent stem cell–derived neural organoids represent a powerful alternative, as they self-assemble into three-dimensional structures that recapitulate key aspects of human neural development while allowing experimental accessibility and external control. Nonetheless, current organoid-based approaches present important limitations: morphogens are typically supplied uniformly through the culture medium, resulting in limited spatial control over patterning, while the ECM is often treated as a passive component. Consequently, biochemical and biophysical cues cannot be independently or jointly tuned in a controlled and spatially defined manner, restricting the ability of existing models to dissect their synergistic roles during human neural patterning.
To address these limitations, this work aims to develop an in vitro platform to spatially guide human neural tube patterning by combining controlled morphogen gradients with the modulation of extracellular matrix properties, enabling the investigation of how biochemical and mechanical cues jointly regulate early neural tissue organization.
Neural organoids are subjected to neural differentiation and patterning protocols and cultured within microfluidic devices designed to generate stable, reproducible and tuneable morphogen gradients with well-defined geometry. The platform enables the application of opposing gradients of dorsal and ventral morphogens—Bone Morphogenetic Proteins (BMPs) and Sonic Hedgehog (SHH), respectively—recapitulating key signalling axes observed in vivo. Integration of the microfluidic system with extracellular matrices of different stiffness allows systematic modulation of the mechanical microenvironment. Morphogen distribution and diffusive properties are characterized through in silico modelling, while the combined effects of biochemical gradients and ECM mechanics on neural patterning are analysed at the level of cellular differentiation.
Overall, this experimental approach provides a controlled experimental framework to investigate how biochemical and mechanical cues cooperatively shape morphogenetic patterning in human neural organoids.