Biomaterial-directed patterning of xenografted brain organoids in-vivo

About This Grant

PROJECT SUMMARY One of the key challenges in the field of neuroscience is studying the living human brain in-situ which is limited to non-invasive monitoring techniques in most cases. Human-derived cortical organoids (hCOs), three- dimensional neural cell aggregates resembling the developing human cortex, have emerged over the past decade as a powerful tool to model human cortical development and disease in vitro. Unlike animal models, hCOs capture human-specific features of development and disease and can achieve greater complexity compared to traditional two-dimensional cell culture models. Extended in vitro culture of hCOs often leads to necrosis at the core due to inadequate oxygen and nutrient perfusion. However, implantation of hCOs into rodent brain facilitates xenograft vascularization and maturation of functional neuronal networks. Despite these advances, hCO xenografts still lack important features of the human cortex, namely cortical lamina, and preexisting hCO cytoarchitectures become scrambled upon implantation. To permit widespread use of this technology, there is a critical need to regulate the laminar patterning of xenografted hCOs in vivo in order to preserve physiologically relevant laminar structures and neuronal circuitry. To address this problem, I propose to leverage biomaterial, controlled-release technology to deliver developmental morphogen gradients to xenografted organoids, directing their laminar organization in situ. These experiments will utilize our recently optimized, cellulose-based polymer (HECMTP), for controlled morphogen delivery alongside our established techniques for multimodal monitoring of organoid xenografts using two-photon imaging and electrophysiological recordings. In Aim 1, I will establish biomaterial-directed gradients of developmental morphogens across hCOs in vitro and identify their effect on hCO laminar patterning. In Aim 2, I will demonstrate the use of a biomaterial-directed morphogen gradient to guide the laminar organization of xenografted hCOs in vivo and monitor functional changes in human neuronal networks as they integrate with the host brain. This project will be the first to monitor and manipulate xenograft patterning in vivo. Its outcomes have the potential to enable numerous studies investigating human cortical development in healthy and pathological states by generating models within a physiologically relevant environment with improved structural and functional relevance as well as reduced inter-model variability. Concurrently, by working on this project I will expand my scientific knowledge base, produce high-profile publications, and lay the groundwork for my future career as an independent investigator.