Hybrid eumelanin/graphene-like/TiO2 bio-interface for mouse embryonic stem cell (mESC) growth: Compatibility toward neurons and beating cardiomyocytes differentiation

The design and fabrication of platforms reproducing the microenvironment in which the cells can properly acquirea specific fate is a decisive step towards the effective exploitation of stem cell-based nanomedicine. Indeed,the environments and the surfaces wherein the cells can attach, migrate and grow significantly affect stem celldifferentiation to specific cell types. In this work, a new-concept bio-interface composed by hybrid eumelanin/graphene-like/titanium dioxide (EU/GL/TiO2) nanostructures has been prepared by an in situ solvothermalmethod with the aim to address those specific properties to sustain survival and growth of stem cells as well as tostimulate their differentiation. Information on the chemical and structural properties of both the organic andinorganic components constituting the hybrid nanomaterial was achieved by different analytical techniques(XRD, FTIR, EPR, TGA, SEM, AFM) while the ability of EU/GL/TiO2 interface to support stem cell adhesion,growth and proliferation was probed by in vitro tests with mouse embryonic stem cells (mESCs). In the end,specific in vitro tests demonstrated that the prepared platform efficiently supports the differentiation of mESCsinto beating cardiomyocytes and neuronal cells. The tests demonstrated that EU/GL/TiO2 holds those biophysicochemicalcharacteristics to prospectively act as a bio-interface. Furthermore, its chemical compositionrepresents a perspective starting point to subsequently explore the decoration with inductive cues that can bereleased upon external stimuli to drive the growth and differentiation of neurons and beating cardiomyocytes.