<b>Substrates mimicking the blastocyst geometry revert pluripotent stem cell to naivety</b>

Naïve pluripotent stem cells (nPSCs) have the highest developmental potential among PSCs, but their <i>in vivo </i>existence in blastocysts is transient. Here, inspired from nature, we designed blastocyst motif substrate to achieve the <i>in vitro</i> reversion of PSCs to a naïve state. The substrate features randomly varied microstrucutres encompassing, but not being limited to, geometry of blastocyst.