In vitro evaluation of 45S5 Bioglass®-derived glass-ceramic scaffolds coated with carbon nanotubes

Highly porous (>90% porosity) 45S5 Bioglass (R)-derived glass-ceramic scaffolds were fabricated by foam replication method, and coated with carbon nanotubes (CNT) (coating thickness: 1 mu m) using electrophoretic deposition (EPD). In vitro cell culture using mesenchymal stem cells (MSCs) was carried out on both scaffold systems (with and without CNT coating) over a 4-week period. By using AlamarBlue (TM), BSA and alkaline phosphatase assays; the cell viability and differentiation were measured quantitatively measured and compared between the two scaffold types. The results showed that both scaffold systems are biocompatible with MSCs and they can support the cellular activity. No cytotoxic effects of CNT were observed under the conditions of the present experiments. Although a lower initial cell viability on the CNT-coated scaffolds was observed, no significant differences were found after 4 weeks of culture compared with the uncoated scaffolds. This work therefore shows that there is in principle no significant improvement of cellular responses by creating a CNT-coating on this type of highly bioactive scaffolds. However, the electrical conductivity introduced by the coating might have the potential to increase cell viability and differentiation when cell culture is carried out under the effect of electrical stimulation. (C) 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 99A: 435-444, 2011.