Matrix promote mesenchymal stromal cell migration with improved deformation via nuclear stiffness decrease.

Bone marrow derived mesenchymal stromal cells (BMSCs) migration to injury site is a prevalent event in tissue repair process after damage occurrence. The migration process is always accompanied with matrix stiffness change. In this study, sodium alginate hydrogels with different stiffness and Transwell chambers with gradient chemical factors were employed to mimic tissue repair in vivo. In this work, in the stiffness range of 1-20 kPa, BMSCs in stiffer matrix showed higher migration speed compared to those in softer matrix. Moreover, stiffer matrix decreased the nuclear stiffness of BMSCs and reduced the expression of lamin A/C, which playing a main role in the regulation of nuclear stiffness. Furthermore, it was found that BMSCs fitted environment by selecting migration strategy. This study provides a novel platform for the investigation of BMSCs migration to mimic the natural tissue repair process.