Influence of Hydrogel Stiffness and Laminin 511 on Human Neural Stem Cell Potency

One of the major constituents of the ECM in the nervous system is laminin (LN); and so far 5 alpha, 3 beta, and 3 gamma units of the LN chain are known, resulting in various combinations of the LN isoforms. However, studying the effect of LN isoforms in vivo is challenging, due to overlapping effects of LN chains. To simplify these effects, LN isoforms can be investigated in vitro on a synthetic hydrogel mimicking neural tissue stiffness and functionalized with the isoform of interest. Currently, LN isoforms, such as LN 511 and others, are used as 2D culture coatings to maintain pluripotency of mouse and human embryonic stem cells, and induced pluripotent stem cells (iPSCs). LN 511 is also used for deriving mature and functional neurons from these iPSCs. As LN 511 has been shown to sustain mature and functional neurons from hPSCs, this gives rise to the question would LN 511 also maintain proliferation and expansion of NSCs? The NSC niche is naturally present in the subventricular zone of the adult brain and is made up of fractal structures, which are mainly composed of LN 511 isoform. Therefore, we hypothesize that LN 511 is a key factor in sustaining the defining characteristics of NSCs to proliferate and self-renew on substrates of optimal stiffnesses. Appropriate microenvironmental cues such as functionality and stiffness must be incorporated to better mimic the NSC niche in vitro. In this study, one of the most abundant LN isoforms present in the NSC niche, LN 511, will be incorporated onto synthetic substrates. The LN 511 will be tethered onto hydrogels with a stiffness ranging from soft, as preferred by neurons, to stiff, as preferred by glia. Thus, we aim to investigate how substrate stiffness, tethered with LN 511, influences NSC behavior through mechanotransduction signaling pathways.