Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: Promising bone implant materials

https://doi.org/10.1016/j.saa.2014.04.004Get rights and content

Highlights

  • Successful grafting of hydroxyapatite on CNTs and graphene.

  • CNTs-HA and Gr-HA were used in proliferation of hFOB 1.19 cells.

  • CNTs-HA and Gr-HA could be promising in bone tissue engineering.

Abstract

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering.

Graphical abstract

Hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19).

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Introduction

Hydroxyapatite (Ca10(PO4)6(OH))2 (HA) is a bioceramic material often used for clinical bone grafting and implantation. HA has the ability to bond chemically with living bone tissue because of its chemical, compositional, biological, and crystal structure which are similar to native apatite in the human skeleton. Furthermore, the bioactivity and biocompatibility of HA enable osteoblast adhesion and proliferation. However, brittle HA is fragile in tension and offers low fracture toughness in comparison with natural bone. This drawback can be substantially minimized by strengthening and toughening HA with carbon nanomaterials while keeping its bioactivity [1].

Recently, carbon nanomaterials have attracted considerable attention due to their unique properties and wide range of applications [2], [3], [4], [5]. Among the carbon nanomaterials, graphene (GR) is a new member with extraordinary electrical, thermal, and mechanical properties that have sparked current interest in materials science [6], [7], [8]. Carbon nanotube on the other hand have extensively been studied since its discovery. Its biocompatibility and bioactivity have also been tested and documented [9].

Till date, there are contradictory reports on the biomedical and biocompatibility of nanomaterials (particularly CNTs) due to its toxicity. However, the toxicity of CNTs has been shown to be reduced through chemical functionalization or coating with substances like polymers, hydroxyapatite or collagen [7], [8], [10]. Zanello et al. reported the mineralization of bone cells on chemically functionalized Single Walled Carbon nanotubes (SWCNTs) with HA. This being the first study on the potential use of SWCNTs as scaffold for bone growth [11]. Balani et al. also applied CNTs in HA coating using plasma spraying to improve the fracture toughness (by 56%) and enhance crystallinity (by 27%). The CNTs reinforced HA coating was further used to culture human osteoblast hFOB 1.19 cells to reveal its biocompatibility with living cells. Unrestricted growth of human osteoblast hFOB 1.19 cells has been observed near the CNTs regions assisted by CNTs surfaces to promote cell growth and proliferation [11], [12], [13].

Herein we report the fabrication of CNTs-HA and Gr-HA, and characterization, including the proliferation and differentiation of bone cells (hFOB 1.19) in the media containing these nanocomposites.

Section snippets

Materials and method

All the reagents were purchased from Aldrich and used without further purification unless otherwise noted. All the aqueous solutions were prepared with ultrapure water obtained from Milli-Q Plus system (Millipore).

Results and discussion

The FTIR spectrum of graphene (Fig. 1a) shows small Osingle bondH stretching vibrations peak at about 3500 cm−1. The band at about 1720 cm−1 is attributed to the stretching vibrations of Cdouble bondO. These suggests the presence of oxygen containing functional groups on the surface of graphene nanosheets after reduction of GO. In addition, a new band appeared in the spectrum of GR at 1509 cm−1, which is ascribed to the skeletal vibration of Gr nanosheets [15]. These conformational changes demonstrate the successful

Conclusions

Both CNTs-HA and Gr-HA are promising composite for scaffolds fabrication in bone tissue engineering as these are able to support in proliferation and differentiation of hFOB cells. However, for in vivo applications, careful consideration of the biocompatibility and toxicity of CNTs and graphene nanosheet is important, which is part of our future work.

Acknowledgments

The authors acknowledge the support from NIH-NIGMS Grant #1SC3GM086245, NIH-NIGMS, Welch foundation and Cooperative Agricultural Research Center.

References (33)

  • C.V. Rao et al.

    Carbon

    (2011)
  • K. Balani et al.

    Biomaterials

    (2007)
  • G.M. Neelgund et al.

    Mater. Res. Bull.

    (2013)
  • S. Yang et al.

    Nanoscale

    (2011)
  • G.M. Neelgund et al.

    Appl. Catal. A: Gen.

    (2011)
  • G.M. Neelgund et al.

    Appl. Catal. B: Environ.

    (2011)
  • G.M. Neelgund et al.

    J. Nanosci. Nanotechnol.

    (2011)
  • A.K. Geim et al.

    Nat. Mater.

    (2007)
  • R. Verdejo et al.

    J. Biomed. Mater. Res. A

    (2009)
  • W. Wang et al.

    J. Biomed. Mater. Res. B Appl. Biomater.

    (2007)
  • G.M. Neelgund et al.

    Mater. Sci. Eng. C

    (2011)
  • R.A. Macdonal et al.

    J. Biomed. Mater. Res. A

    (2005)
  • L. Zanello et al.

    Nano Lett.

    (2006)
  • J.C. Meyer et al.

    Nature

    (2007)
  • W.S. Hummers et al.

    J. Am. Chem. Soc.

    (1958)
  • S.A. Harris et al.

    J. Bone Miner. Res.

    (1995)
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