Biomedical Engineering Reference
In-Depth Information
Braided scaffolds are also suitable for ligament tissue engineering
as they possess high mechanical resistance. Recently Laurent
et al
. in
a series of manuscripts [LAU 11a, LAU 12, LAU 11b, LAU 14]
developed a computational approach to design and fabricate a
multilayered braided ligament structure as shown in Figure 7.2(g) into
which a pore size gradient is created in order to enable successful and
homogeneous cell and tissue infiltration. Finite element analysis
considering fiber contact/friction was utilized in order to predict the
geometry and the mechanical behavior of the scaffold in a large
deformation framework. This method was proven highly accurate as
there was an excellent match between the computational prediction
and the experimental mechanical properties. The rationale behind the
development of this highly sophisticated tool was to assess and control
the mechanical loading and strain at the fiber level. This combined
with cell seeding and subsequent culture into bioreactor applying
cyclic stretching can allow the biological maturation of a neo-ligament
in a highly controlled manner. This would permit us to accurately
apply a specific deformation onto the fibers and hence onto the cell
adhered onto the biomaterial. Biocompatibility assays have
demonstrated that ovine bone marrow stem cells were capable of
proliferating and infiltrating the braided structure over a 28 day
period.
7.4. Concluding remarks
Tissue engineering is evolving rapidly and is a promising
technology whose application is nevertheless limited by the high cost
associated with the
in vitro
maturation of the neo-tissue. In addition,
some the constructs developed may not be able to withstand the
physiological impact once implanted in humans. Therefore, further
investigations are necessary in order to translate these findings from
the bench to the bedside. The other alternative, non-degradable
ligaments and their recent advances, also offer some promise but
significantly suffer from the reputation they gained two decades ago.
Here again, long-term clinical studies are required to establish the
clinical studies that are required to establish the clinical safety of these
structures.
