Volumetric compression by heterogeneous scaffold embedding promotes cerebral organoid growth and maturation

While biochemical regulation has been extensively studied in cerebral organoid modeling protocols, the role of mechano-regulation in directing stem cell fate and organoid development has been relatively unexplored. Volumetric compression, a key aspect of natural brain development, is known to influence neuronal differentiation. However, stiff interpenetrating network compression fails to accurately replicate the dynamic organoid development observed in nature. In this study, we present a novel method of heterogeneous embedding using an alginate-shell-Matrigel-core system. This approach allows for cell-Matrigel remodeling by the inner layer and provides moderate normal compression through the soft alginate outer layer. Our results show significant improvements in cell proliferation and maturation of cerebral organoids, as evidenced by increased expression of neuronal markers such as neurofilament (NF) and microtubule-associated protein 2 (MAP2). Compared to non-alginate embedding and alginate compression groups, volume growth remains unimpeded. Our findings demonstrate the successful mechanical regulation of cerebral organoids, which not only mimics the mechanical environment of brain development but also exhibits a regular growth profile with enhanced maturation. These results highlight the importance and potential practical applications of mechano-regulation in the establishment of brain organoids. Gene expression patterns reflect how cells respond to external stimuli. To examine the effect of alginate compression on organoids, we collected 2 control (without alginate encapsulation) and 3 experimental samples (encapsulated with calcium alginate) for RNA sequencing. RNA isolation and sequencing were performed by BGI Genomics Corporation using the Equalbit RNA BR Assay Kit.