Abstract |
The increasing demand for biocompatible bone substitutes has made it a
priority to tissue engineering and regenerative medicine scientists. Last
decades, there is an interest for topographic features on the implants, which
have been proven to mechanically regulate cell behavior and functions. The
soft lithography techniques provide the opportunity to replicate accurately cell
culture patterned surfaces on polymers of interest, where the effect of various
topographical cues on cellular functions can be studied. The most studied
synthetic polymers in bone tissue regeneration are aliphatic polyesters, due to
their advantage of being easily tailored according to the demands. However,
there are still some concerns about osteoconductivity, absorption timing and
local pH alterations to polymers’ surfaces.
In this study, the material of interest is the polycaprolactone (PCL), a
biodegradable synthetic polymer that has been widely used to produce 3D
scaffolds due to its biocompatibility, biodegradability, structural stability and
excellent mechanical properties. Cell culture studies were carried out using
mouse Mesenchymal Stem Cells (mMSCs), an important cell source in tissue
engineering due to their ability to self-renew, proliferate, and differentiate into a
wide range of tissue-specific lineages, including chondrogenic, adipogenic and
osteogenic lineages. The aim of this study is to investigate the effect of
patterned and non-patterned (flat) PCL surfaces on mMSCs morphology,
adhesion, proliferation and osteogenic differentiation.
In an attempt to enhance the cell attachment properties of PCL, we have used
ultrafast laser patterned surfaces. Ultrafast pulsed laser irradiation is
considered as a simple, precise and effective microfabrication method to
produce structures of controlled geometry and pattern regularity. In our study,
two types of PCL patterned surfaces (low and high roughness) and a PCL nonpatterned (flat) surface were fabricated via soft lithography method, by using
such patterned masters. Their topographical features and surface wettability
were assessed by Scanning Electron Microscopy (SEM) and static contact
angle measurements. In order to study the effect of surface properties on cell
behavior, the MSCs were cultured on PCL patterned and non-patterned
substrates.
Specifically, the effect of topography on cytoskeleton organization (cell shape),
the focal adhesion activity and the cell mechanotransduction were studied.
Furthermore, the ability of MSCs cultured on patterned PCL surfaces with
various stiffness and topographies to differentiate toward osteogenic lineage
and to produce a mineralized matrix were evaluated. It is assumed that our
tailor-made PCL micro-environments give the opportunity to affect the cellular
behavior and seem to be promising in the field of bone tissue engineering and
regenerative medicine in the future.
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