Differentiation properties of 3D scaffolds nanostructured with multi-walled carbon nanotubes on human induced pluripotent stem cells.

Implementation of stem cell therapy using novel nanotechnologies is a fruitful approach for regenerative medicine. Induced pluripotent stem cells (iPSC) are considered a gold standard for stem cells research for personalized regenerative medicine, especially for tissues with low regenerative capabilities. To overcome some limitations of existing systems, a novel microporous, self-standing, elastomeric 3D scaffold of polydimethylsiloxane with micrometric cavities of tunable sizes, nanostructured with multi-walled carbon nanotubes (MWCNTs) was developed to investigate its biocompatibility and differentiation potential towards iPSC. Four types of 3D MWCNTs scaffolds were selected to study the role of scaffolds pore size (small: 100-250 µm; large: 250-600 µm) and the level of MWCNTs nanostructuration (3% w/w and 6% w/w) in their effects on iPSC. All scaffolds appeared highly biocompatible with iPSC for up to 7 days, but 3D MWCNTs scaffolds with large pore size (250-600 µm) allowed the most adequate environment for cell growth, increasing cell mass in absence of proliferation stimuli. Only at this porosity, regardless of MWCNTs amount, the iPSC gene expression profile was characterized by a distinct pattern, compatible with a reduced pluripotency and a mesoderm-like differentiation. These results might support possible application of these scaffolds in regenerative medicine, opening new scenarios for stem cell-based approaches.