Efeitos dos nanotubos de carbono funcionalizados com hialuronato de sódio no comportamento de cultura de osteoblastos primários

Abstract

The aim of this study was to evaluate the effects of sodium hyaluronate (HY), singlewalled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT) and their functionalization with HY (HY-SWCNT and HY-MWCNT) on the behavior of primary osteoblasts. Before carrying out the in vitro experiments, the biocomposites were characterized by transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis. Primary osteoblasts were obtained from calvarial bones of newborn Wistar rats. It was assessed cell viability using the 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2h-tetrazolium bromide (MTT) assay and the double staining with propidium iodide and Hoechst, formation of mineralized bone nodules by von Kossa staining and mRNA expression of proteins involved in bone formation. TEM analysis showed SWCNT as bundles formed by different numbers of single units and MWCNT with thick wall formed by several concentrically arranged layers. Raman spectra of SWCNT and HY-SWCNT revealed low frequency peaks, which differs from the MWCNT and HY-MWCNT. Thermogravimetric analysis of HYSWCNT and HY-MWCNT samples confirmed the functionalization of carbon nanotubes with HY. Treatment with low concentrations of these biocomposites did not reduce the cell viability of primary osteoblasts. Furthermore, there was a significant increase in the deposition of mineralized bone nodules in primary osteoblast cultures that were treated with HY, HY-SWCNT, MWCNT and HYMWCNT, which can be explained, at least in part, by increases in the mRNA expression of collagen types I and III, osteocalcin and bone morphogenetic proteins 2 and 4. Thus, our data indicated that HY, SWCNT, HY-SWCNT, MWCNT and HYMWCNT are potentially useful for the development of new strategies for bone tissue engineering.