Abstract
Stem cell transplantation is a promising approach for the treatment of traumatic brain injury, although the therapeutic benefits are limited by a high degree of donor cell death. Tissue engineering is a strategy to improve donor cell survival by providing structural and adhesive support. However, optimization prior to clinical implementation requires expensive and time‐consuming in vivo studies. Accordingly, we have developed a three‐dimensional (3‐D) in vitro model of the injured host–transplant interface that can be used as a test bed for high‐throughput evaluation of tissue‐engineered strategies. The neuronal‐astrocytic cocultures in 3‐D were subjected to mechanical loading (inducing cell death and specific astrogliotic alterations) or to treatment with transforming growth factor‐β1 (TGF‐β1), inducing astrogliosis without affecting viability. Neural stem cells (NSCs) were then delivered to the cocultures. A sharp increase in the number of TUNEL^+^ donor cells was observed in the injured cocultures compared to that in the TGF‐β1‐treated and control cocultures, suggesting that factors related to mechanical injury, but not strictly astrogliosis, were detrimental to donor cell survival. We then utilized the mechanically injured cocultures to evaluate a methylcellulose‐laminin (MC‐LN) scaffold designed to reduce apoptosis. When NSCs were codelivered with MC alone or MC‐LN to the injured cocultures, the number of caspase^+^ donor cells significantly decreased compared to that with vehicle delivery (medium). Collectively, these results demonstrate the utility of an in vitro model as a preanimal test bed and support further investigation of a tissue‐engineering approach for chaperoned NSC delivery targeted to improve donor cell survival in neural transplantation. © 2007 Wiley‐Liss, Inc.