Osteogenic properties of 3D-printed silica-carbon-calcite composite scaffolds: Novel approach for personalized bone tissue regeneration

Carbon enriched bioceramic (C-Bio) scaffolds have recently shown exceptional results in terms of their biological and mechanical properties. The present study aims at assessing the ability of the C-Bio scaffolds to affect the commitment of canine adipose-derived mesenchymal stem cells (cAD-MSCs) and investigating the influence of carbon on cell proliferation and osteogenic differentiation of cAD-MSCs in vitro. The commitment of cAD-MSCs to an osteoblastic phenotype has been evaluated by expression of several osteogenic markers using real-time PCR. Biocompatibility analyses through 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), lactate dehydrogenase (LDH) activity, hemolysis assay, and Ames test demonstrated excellent biocompatibility of both materials. A significant increase in the extracellular alkaline phosphatase (ALP) activity and expression of runt-related transcription factor (RUNX), ALP, osterix (OSX), and receptor activator of nuclear factor kappa-B ligand (RANKL) genes was observed in C-Bio scaffolds compared to those without carbon (Bio). Scanning electron microscopy (SEM) demonstrated excellent cell attachment on both material surfaces; however, the cellular layer on C-Bio fibers exhibited an apparent secretome activity. Based on our findings, graphene can improve cell adhesion, growth, and osteogenic differentiation of cAD-MSCs in vitro. This study proposed carbon as an additive for a novel three-dimensional (3D)-printable biocompatible scaffold which could become the key structural material for bone tissue reconstruction.