Morphological Characterization of a Novel Scaffold for Anterior Cruciate Ligament Tissue Engineering

Tissue engineering offers an interesting alternative to current anterior cruciate ligament
(ACL) surgeries. Indeed, a tissue-engineered solution could ideally overcome the long-
term complications due to actual ACL reconstruction by being gradually replaced by
biological tissue. Key requirements concerning the ideal scaffold for ligament tissue en-
gineering are numerous and concern its mechanical properties, biochemical nature, and
morphology. This study is aimed at predicting the morphology of a novel scaffold for
ligament tissue engineering, based on multilayer braided biodegradable copoly(lactic
acid-co-(e-caprolactone)) (PLCL) fibers The process used to create the scaffold is briefly
presented, and the degradations of the material before and after the scaffold processing
are compared. The process offers varying parameters, such as the number of layers in the
scaffold, the pitch length of the braid, and the fibers’ diameter. The prediction of the mor-
phology in terms of pore size distribution and pores interconnectivity as a function of
these parameters is performed numerically using an original method based on a virtual
scaffold. The virtual scaffold geometry and the prediction of pore size distribution are
evaluated by comparison with experimental results. The presented process permits crea-
tion of a tailorable scaffold for ligament tissue engineering using basic equipment and
from minimum amounts of raw material. The virtual scaffold geometry closely mimics the
geometry of real scaffolds, and the prediction of the pore size distribution is found to be
in good accordance with measurements on real scaffolds. The scaffold offers an intercon-
nected network of pores the sizes of which are adjustable by playing on the process pa-
rameters and are able to match the ideal pore size reported for tissue ingrowth. The
adjustability of the presented scaffold could permit its application in both classical ACL
reconstructions and anatomical double-bundle reconstructions. The precise knowledge of
the scaffold morphology using the virtual scaffold will be useful to interpret the activity
of cells once it will be seeded into the scaffold. An interesting perspective of the present
work is to perform a similar study aiming at predicting the mechanical response of the
scaffold according to the same process parameters, by implanting the virtual scaffold
into a finite element algorithm.