Surface biocompatibility study of electronic grade 2-dimensional materials with stem cells and motor neurons

Two-dimensional (2D) materials have the potential to become the functional elements of future bioelectronic interfaces. So far, studies directed towards understanding their biocompatibility have mostly utilized exfoliated flakes and suspensions resulting in large uncertainty and discrepancies in their cytotoxicity measures. In this work, we have performed a comprehensive experimental study of in vitro surface cell-viability of large-scale grown sheets of 2D materials that include platinum diselenide (PtSe₂), platinum ditelluride (PtTe₂), molybdenum disulfide (MoS₂), and graphene. We cultured embryonic mESCs (ESCs) and derived motor neurons (MNs) over the surface of large-area 2D material sheets in a controlled environment and quantified surface cell-viability using the MTT colorimetric assay, and fluorescence live-dead imaging was performed to qualitatively understand the trends in cellular growth and proliferation. The assay results suggest that PtSe₂ displays surface cell-viability values (ESCs: mean = 97%, MNs: 90%) on par with that of the controls, graphene, and MoS₂ (ESCs: combined means = 105%, MNs: combined means = 102%), with PtTe₂ displaying the lowest surface cell-viability value (ESCs: mean = 6%, MNs: mean = 61%). We hope these results from the in vitro surface biocompatibility experiments can help large-area 2D materials become the possible alternatives for usage in future cell-culture scaffolds and bioelectronic implants