Nanostructured Graphene Surfaces Promote Different Stages of Bone Cell Differentiation
Nano-Micro Lett.
Nanostructured Graphene Surfaces Promote Different Stages of Bone Cell Differentiation
F. F. Borghi 0 1 2 3 4 5
. P. A. Bean 0 1 2 3 4 5
. M. D. M. Evans 0 1 2 3 4 5
. T. van der Laan 0 1 2 3 4 5
. S. Kumar 0 1 2 3 4 5
. K. Ostrikov 0 1 2 3 4 5
0 CSIRO Manufacturing , P.O. Box 52, North Ryde, NSW 2113 , Australia
1 Plasma Nanoscience, School of Physics, The University of Sydney , Sydney, NSW 2006 , Australia
2 & K. Ostrikov
3 CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organization , P.O. Box 218, Lindfield, NSW 2070 , Australia
4 School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Brisbane, QLD 4000 , Australia
5 Brazilian Centre for Physics Research (CBPF) , Rua Dr. Xavier Sigaud - 150, Urca, Rio de Janeiro, RJ CEP 22290180 , Brazil
Nanostructured graphene films were used as platforms for the differentiation of Saos-2 cells into bonelike cells. The films were grown using the plasma-enhanced chemical vapor deposition method, which allowed the production of both vertically and horizontally aligned carbon nanowalls (CNWs). Modifications of the technique
Highlights
CNW
2 μm
HGL
2 μm
Nanostructure
Cell interaction
Differentiation
Higher Ca
production
Higher Alkaline
Phosphatase
production
allowed control of the density of the CNWs and their
orientation after the transfer process. The influence of two
different topographies on cell attachment, proliferation,
and differentiation was investigated. First, the transferred
graphene surfaces were shown to be noncytotoxic and were
able to support cell adhesion and growth for over 7 days.
Second, early cell differentiation (identified by cellular
alkaline phosphatase release) was found to be enhanced on
the horizontally aligned CNW surfaces, whereas
mineralization (identified by cellular calcium production), a later
stage of bone cell differentiation, was stimulated by the
presence of the vertical CNWs on the surfaces. These
results show that the graphene coatings, grown using the
presented method, are biocompatible. And their
topographies have an impact on cell behavior, which can be useful
in tissue engineering applications.
1 Introduction
The use of nanomaterials for biological control has been a
recurring topic of study over the past decades [
1–7
]. In
addition to conventional chemical stimulus strategies,
nanomaterials possess reduced-scale features that provide
physical control over bacteria and cells [
3–8
]. Designed
nanofeatures are capable of directing and applying forces
to cells in order to trigger the activation and/or suppression
of genes involved in a number of cellular processes, such as
cell adhesion, proliferation, and differentiation (a process
where cells become another cell type) [
1, 9–12
]. Therefore,
the use of nanomaterials presents an interesting opportunity
to control the fate of cells for the development of
biomedical technologies, such as cell therapies and tissue
engineering.
Graphene has attracted considerable attention in the
biomedical field owing to its unique and specific properties
[
12–16
]. The chemistry of carbon is well known, which
makes graphene a useful material for molecular attachment
and functionalization. The potential toxicity of graphene
and its derivatives (e.g., a solution of graphene
nanoplatelets) has been investigated to determine their capabilities
for applications in biomedicine [
17–20
]. For each
nanostructure and variations on functionalization and
concentration, different results were obtained. Studies on the
interactions of graphene coatings/films with cells, using
cell-based assays conducted in vitro, have also been
reported. Glass and silicon coated with graphene films
showed noncytotoxic responses and have been
demonstrated to allow the proliferation of diverse types of cells
[
12, 21–26
].
Recent reports have described the use of graphene-based
nanostructures to control the differentiation of neural cells
[
17, 27
]. Glass coated with single-layer graphene, in
combination with growth factors and proteins, was used to
enhance the differentiation of human neural stem cells into
neurons [28]. Another study showed that reduced graphene
oxide films could support the proliferation of neural stem
cells and enhance their specific differentiation [
29
]. The
effects of graphene films on cellular responses were also
investigated using human osteoblasts (Saos-2 bone-like
cells) and mesenchymal stem cells (MSCs) for bone
regeneration applications [
19
]. Results showed that
graphene films presented no cytotoxic effects on these cell
types and were supportive of both cell adhesion and
proliferation [
24
]. Interestingly, although the use of graphene
films did not influence the overall proliferation rate of
MSCs, it did promote their differentiation into the bone
pathway more efficiently than did differentiation factors
alone [
25
]. The origin of the enhance (...truncated)