Brain organoid protocols and limitations

Abstract

Stem cell-derived organoid technology is a powerful tool that revolutionizes the field of biomedical research and extends the scope of our understanding of human biology and diseases. Brain organoids especially open an opportunity for human brain research and modeling many human neurological diseases, which have lagged due to the inaccessibility of human brain samples and lack of similarity with other animal models. Brain organoids can be generated through various protocols and mimic whole brain or region-specific. To provide an overview of brain organoid technology, we summarize currently available protocols and list several factors to consider before choosing protocols. We also outline the limitations of current protocols and challenges that need to be solved in future investigation of brain development and pathobiology.

Adult human brain tissue cultures to study neuroHIV

“…Though valuable, most preclinical studies of HIV-1 brain infection currently rely on either small animal models that only express a subset of viral proteins, humanized mice that don't fully reconstitute human CNS cells and architecture, or SIVinfected macaques, which don't fully reflect HIV-associated neurocognitive pathologies [49][50][51][52]. Some HIV-1 studies take advantage of brain organoids made of human CNS cells [53][54][55], but these systems fail to recapitulate the structure of the human brain and lack its cellular diversity [56]. Further, they require addition of microglia from an external source or derive microglia from induced pluripotent stem cells [57], which is an important caveat since microglia remain as HIV reservoirs in people taking antiretroviral therapies [58].…”

A human-specific, concerted repression of microcephaly genes contributes to radiation-induced growth defects in forebrain organoids

“…However, we do not believe that, if it happened, this would have influenced the main findings of our study, especially since we found similar results in monolayer NPC cultures. In any case, many different protocols for brain organoid cultures exist, each with their advantages and drawbacks (100,101). A recent study compared organoid cultures in the presence and absence of an exogenous extracellular matrix and they observed no major differences in morphology, cellular composition or gene expression profiles although organoids cultured in Matrigel did induce transcriptional pathways of eye development (102).…”

Guidelines for Manufacturing and Application of Organoids: Brain

“…Despite these advantages, the fabrication of brain organoids remains a complex and challenging process due to the lack of standardization in production methods, posing potential risks for their application in drug discovery pipelines. Moreover, organoids inherently lack reproducibility and quantifiability for use in disease modeling and drug screening, indicating that there is an urgent need for the development of related technologies ( 19 - 21 ).…”