Activated Carbon Fiber Incorporated with Metal Ions: Characterization and Biological Interactions In Vitro

Due to the constant need to develop biocompatible materials with osteoconductive and osteoinductive properties, the main objective of this study was to evaluate and characterize the carbon fiber obtained from fiber polyacrylonitrile textile carbon fiber (PAN), in the different forms: non-activated carbon fiber felt (NACFF) and activated carbon fiber felt (ACF) with silver (Ag-ACF), gold (Au-ACF), copper (Cu-ACF), palladium (Pd-ACF) and platinum (Pt-ACF), on the cell behavior and osteogenesis of mesenchymal cells. For characterization: scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Raman analysis. In vitro analysis was performed on rat mesenchymal stem cells. For each experimental group, 5 wells (n = 5) were made where cell proliferation (CP): cell viability (CV), mineralization nodule formation (MNF), total protein content (PT) and alkaline phosphatase activity (APC) were quantified, and cell morphology was analyzed by direct fluorescence, genotoxicity and cell interaction by SEM. The data passed the normality test and was followed by the one-way ANOVA test, followed by the Tukey test, using the conventional significance level of 5%. All the samples were statistically similar in terms of cell proliferation, except for the Ag-ACF group in relation to the control group (C). For cell viability, C obtained greater viability than the other groups, while ACF obtained a statistical difference and was superior to the Ag-ACF, Cu-ACF, Pt-ACF groups, being statistically similar to the Au-ACF and Pd-ACF groups. In the evaluation of ACP, the Ag-ACF and Cu-ACF groups were lower than the C, and other groups; for the characterization tests Au-ACF and Pd-ACF showed a more homogeneous metal distribution compared to the other groups. Cu-ACF and Ag-ACF showed some toxicity and low induction of osteoblastic differentiation. Although platinum showed relative cellular viability, a high micronucleus count was reported for this ion. In conclusion, ACF has the potential to be developed as a future biomaterial with good cell viability. Carbon fibers incorporated with gold and palladium ions showed potential for future application as supports for bone repair.