Artificial Meshed\nVessel-Induced Dimensional Breaking\nGrowth of Human Brain Organoids and Multiregional Assembloids

Brain organoids are widely used to model brain development\nand\ndiseases. However, a major challenge in their application is the insufficient\nsupply of oxygen and nutrients to the core region, restricting the\nsize and maturation of the organoids. In order to vascularize brain\norganoids and enhance the nutritional supply to their core areas,\ntwo-photon polymerization (TPP) 3D printing is employed to fabricate\nhigh-resolution meshed vessels in this study. These vessels made of\nphotoresist with densely distributed micropores with a diameter of\n20 μm on the sidewall, are cocultured with brain organoids to\nfacilitate the diffusion of culture medium into the organoids. The\nvascularized organoids exhibit dimensional breaking growth and enhanced\nproliferation, reduced hypoxia and apoptosis, suggesting that the\n3D-printed meshed vessels partially mimic vascular function to promote\nthe culture of organoids. Furthermore, cortical, striatal and medial\nganglionic eminence (MGE) organoids are respectively differentiated\nto generate Cortico-Striatal-MGE assembloids by 3D-printed vessels.\nThe enhanced migration, projection and excitatory signaling transduction\nare observed between different brain regional organoids in the assembloids.\nThis study presents an approach using TPP 3D printing to construct\nvascularized brain organoids and assembloids for enhancing the development\nand assembly, offering a research model and platform for neurological\ndiseases.