Toward a neurospheroid niche model: optimizing embedded 3D bioprinting for fabrication of neurospheroid brain-like co-culture constructs

Abstract

A crucial step in creating reliable in vitro platforms for neural development and disorder studies is the reproduction of the multicellular three-dimensional (3D) brain microenvironment and the capturing of cell-cell interactions within the model. The power of self-organization of diverse cell types into brain spheroids could be harnessed to study mechanisms underlying brain development trajectory and diseases. A challenge of current 3D organoid and spheroid models grown in petri-dishes is the lack of control over cellular localization and diversity. To overcome this limitation, neural spheroids can be patterned into customizable 3D structures using microfabrication. We developed a 3D brain-like co-culture construct using embedded 3D bioprinting as a flexible solution for composing heterogenous neural populations with neurospheroids and glia. Specifically, neurospheroid-laden free-standing 3D structures were fabricated in an engineered astrocyte-laden support bath resembling a neural stem cell niche environment. A photo-crosslinkable bioink and a thermal-healing supporting bath were engineered to mimic the mechanical modulus of soft tissue while supporting the formation of self-organizing neurospheroids within elaborate 3D networks. Moreover, bioprinted neurospheroid-laden structures exhibited the capability to differentiate into neuronal cells. These brain-like co-cultures could provide a reproducible platform for modeling neurological diseases, neural regeneration, and drug development and repurposing.

Glutamatergic Neurons Differentiated from Embryonic Stem Cells: An Investigation of Differentiation and Associated Diseases

“…Cai et al were able to model neurodegenerative diseases such as AD by using the acoustofluidic method to rapidly construct 3D neurospheroids and inflammatory microenvironments [ 44 ]. Utilizing embedded 3D bioprinting, Li et al also develop a 3D brain-like co-culture structure for studying the cell–cell interactions, neurospheroids/glia and the brain microenvironment [ 45 ]. Nonetheless, the effect of the neuronal microenvironment on ESC-derived glutamatergic neurons, and vice versa, both require more investigation and pinpointing of some groundbreaking findings.…”

Neuroinflammatory In Vitro Cell Culture Models and the Potential Applications for Neurological Disorders

“…standardized operations and detection parameters also limit its widespread use (Jackson et al, 2019). In recent years, 3D printing has emerged as an alternative manufacturing method that allows faster, cheaper manufacturing, precise size control, built-in measurement technology, and greater design flexibility (Li et al, 2020). Combining 3D printing technology with the advantages of high throughput detection, automatic detection, and low operating cost of microfluidics solves the problem of the complex multi-step structure of the microfluidic device and can be used as an alternative method of traditional microfluidics manufacturing.…”

Neurorepair and Regeneration of the Brain: A Decade of Bioscaffolds and Engineered Microtissue

“…3D bioprinting can improve in vitro platforms for modeling neurological diseases, neural regeneration, and drug development. Li et al (2020) developed a 3D brain-like co-culture construct where neurospheroid 3D structures were fabricated in an astrocyte-laden resembling a NSC niche environment. Then, the authors used a photo-cross-linkable bioink to bioprint neurospheroid layers.…”