Multi and single walled carbon nanotubes: effects on cell responses and biomineralization of osteoblasts cultures
The use of carbon nanotubes (CNTs) on the development of biomaterials has been motivated by their excellent mechanical properties that could improve synthetic bone materials. However, the toxicity of CNTs on the tissue/implant interface and their influence on the biomineralization process have some contradictions. We investigated the influence of CNTs on osteoblasts plated on titanium (Ti) discs or plastic surfaces. We evaluated osteoblasts viability, alkaline phosphatase (ALP) activity, and mineralized matrix formation in the different phases of osteoblasts growth in the presence of single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs). An increase in osteoblasts viability was observed at the 21st day for both CNTs on plastic surface, while viability increased for MWCNTs at the 7th and 14th days and at the 7th day for SWCNTs on Ti discs compared to control. ALP activity increased at the 14th and 21st days for MWCNTs on plastic surfaces. For cells incubated with SWCNTs, an increase in ALP activity at the 7th day for plastic surface and at the 14th day for both materials (plastic and Ti) was observed. The mineralized matrix formation increased at the 21st day on plastic surface with SWCNTs, and at the 14th and 21st days for both CNTs on Ti discs. In conclusion, both SWCNTs and MWCNTs are not toxic to osteoblasts at concentrations up to 5 × 10−5 and 1.3 × 10−2 mg/mL, respectively, either in Ti discs or plastic surfaces. In the long term, the cells grown in contact with both CNTs and Ti presented better results regarding bone-like nodules formation.
KeywordsPlastic Surface Radial Breathing Mode Osteoblast Culture Biomineralization Process Osteoblast Growth
This study was supported by the Brazilian agencies FAPESP (2011/22232-5), CAPES (NanoBiotec), and CNPq. The authors thank Priscila Cerviglieri for linguistic advice. We also thank José Augusto Maulin for operation of the TEM equipment and Dr. Rodrigo Silva for operation of the SEM/EDS equipment. PC, RRG, and APR are CNPq researchers; DCZ and ANF received a CNPq scholarship.
Compliance with ethical standards
Conflict of interest
No conflicting financial interests exist.
- 1.Barrientos-Durán A, Carpenter EM, zur Nieden NI, Malinin TI, Manzaneque JCR, Zanello LP. Carboxyl-modifed single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model. Int J Nanomed. 2012;43:2079–86.Google Scholar
- 4.Tonelli FMP, Santos AK, Gomes KN, Lorençon E, Guatimosim S, Ladeira LO, Resende RR. Carbon nanotube interaction with extracellular matrix proteins producing scaffolds for tissue engineering. Int J Nanomed. 2012;7:4511–29.Google Scholar
- 13.Mikael PE, Amini AR, Basu J, Arellano-Jimenez MJ, Laurencin CT, Sanders MM, Carter CB and Nukavarapu SP. Functionalized carbon nanotube reinforced scaffolds for bone regenerative engineering: fabrication, in vitro and in vivo evaluation. Biomed Mater. 2014;9(3):035001-1-13.Google Scholar
- 31.van der Zande M, Walboomers XF, Brännvall M, Olalde B, Jurado MJ, Alava JI, Jansen JA. Genetic profiling of osteoblast-like cells cultured on a novel bone reconstructive material, consisting of poly-l-lactide, carbon nanotubes and microhydroxyapatite, in the presence of bone morphogenetic protein-2. Acta Biomater. 2010;6:4352–60.CrossRefGoogle Scholar