Optimization of adhesive conditions for neural differentiation of murine embryonic stem cells using hydrogels functionalized with continuous Ile-Lys-Val-Ala-Val concentration gradients.

Stem cell therapies, which aim to restore neurological function after central nervous system injury, have shown increased efficacy when a tissue engineering matrix is implanted with cells compared to implantation of the cells alone. However, much work still needs to be done to characterize materials that can be used to facilitate and direct the differentiation of implanted cells. In the current study, polyethylene glycol hydrogels functionalized with continuous Ile-Lys-Val-Ala-Val (IKVAV) concentration gradients were fabricated and utilized to systematically study and optimize the adhesive conditions for neural differentiation of mouse embryonic stem cells in two- and three-dimensional environments. The results suggest that 570 μM and 60 μM are the optimal IKVAV concentrations for 2D and 3D neural differentiation, respectively, to maximize mRNA expression of neuron-specific markers and neurite extension while minimizing apoptotic activities in cultured cells compared to those exposed to higher IKVAV concentrations. The combinatorial approach presented in this work demonstrates that hydrogels functionalized with bioactive peptides provide a defined and tunable platform that can be employed to characterize and improve culture conditions for superior survival, maturation and integration of implanted cells, leading to enhanced restoration of neurological function for those receiving stem cell therapies after traumatic brain and spinal cord injuries.