The Emerging Applications of Graphene Oxide and Graphene in Tissue Engineering - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 280

Biomimetic materials are synthetic biomedical materials, systems, or
devices that are designed and engineered based on knowledge gained
from biological systems or by mimicking their structure and function.
Biomimetic materials can be simpler and can exhibit enhanced perfor-
mance over conventional materials. Over the previous decades, there has
been a great deal of effort to fabricate biomimetic multiscale structures to
achieve multifunctional integration within a single material. Within this
concept, GO, graphene and their functionalized forms have been used to
mimic various natural structures, such as butterfl y wings [48], rose pet-
als [49], honeycomb [50], and nacre [51]. Although biomimetic graphene-
based materials are of great interest in various biomedical applications, it
is rather diffi cult to design and fabricate these materials. Unlike polymeric
materials, which can be shaped into any desired form using conventional
fabrication techniques, such as lithography, imprinting or other chemi-
cal routes, constructing hierarchical structures using graphene-based
sheets is not a straightforward task. Here, irregular stacking and the sur-
face manipulation of graphene sheets are useful approaches to construct
various biomimetic micro- and nanostructures. The laser manipulation of
GO or graphene fi lms is commonly used to prepare such structures. This
technique has several advantages, including its speed, cleanliness, and
high effi ciency [52]. More importantly, the oxygen content of surfaces as
measured by the composition and density of oxygen-containing groups
can be easily adjusted by tuning the laser intensity [52]. The biomimetic
graphene materials fabricated by this technique are promising scaffolds
for TE applications [48]. Yin et al. suggested another strategy to fabricate
biomimetic graphene-based structures [50]. These authors were inspired
by the natural honeycomb and developed a self-assembly method to con-
struct honeycomb-mimetic graphene structures. This fabrication strategy
was based on the breath fi gure method, in which the GO is homogenously
dispersed in an organic solvent using cationic surfactants. The solution
was then cast onto a glass substrate under highly humid airfl ow (~ 85%
humidity). An organized honeycomb appeared following complete evap-
oration of both water and organic solvents. The humidity is a critical fac-
tor controlling the production of honeycomb structures, with a humidity
greater than 30% required to form a honeycomb-like structure. These bio-
mimetic structures may provide greater functionality and performance
compared to conventional graphene materials.

12.3 Graphene Oxide and its Cell and

TE Applications

GO is an intermediate material in the chemical synthesis of graphene,
consisting of oxygen-containing chemical groups, such as carboxyls,