POLYCAPROLACTONE BASED NANOFIBER SCAFFOLDS CAN MIMIC COLLAGEN FIBRIL DIAMETER DISTRIBUTION OF HEALTHY AND INJURED SHEEP ANTERIOR CRUCIATE LIGAMENT
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Date
2021-12
Authors
Smatov, Smail
Journal Title
Journal ISSN
Volume Title
Publisher
Nazarbayev University School of Engineering and Digital Sciences
Abstract
A ligament is a soft connective tissue with a hierarchical structure that attaches
bone to bone. The Anterior Cruciate Ligament (ACL) tissue connects femur and tibia, and
possesses low potential for self-regeneration due to its hypovascularity and
hypocellularity. ACL injuries in the knee joint are prevalent among the people actively
involved in sports such as basketball, football and skiing. Unfortunately, currently
available clinical treatments cannot fully restore the injured tissue as indicated by low
success rates in clinical procedures. Tissue engineering strategies can provide
alternative approaches with a potential of restoring the injured ligaments by employing
biomimetic scaffolds that are similar to native tissue in terms of structure, composition
and functions.
Here, it is hypothesized that the electrospun fibers with bimodal and unimodal
distributions will mimic the collagen fibril diameter distribution of healthy and injured sheep
ACL, respectively. To test this hypothesis, it was aimed to, firstly, create an injured sheep
ACL by applying mechanical loading to the healthy ACL tissue until rupture. Secondly,
Transmission Electron Microscopy (TEM) characterization was performed on the healthy
and injured ACL tissues to determine collagen fibril diameter distributions. Thirdly,
Polycaprolactone (PCL) scaffolds were produced via electrospinning method to mimic the
bimodal and unimodal distributions of collagen fibrils in the healthy and injured tissues.
Finally, mechanical characteristics of ACL and PCL electrospun scaffolds were
determined at a crosshead speed of 5 mm/min in tension.
Findings of this study demonstrated that the bimodal distribution of collagen fibril
diameter of ACL changes to unimodal upon injury, resulting in a reduction in mean
diameter. The fiber diameter distributions of polycaprolactone electrospun scaffolds were
shown to mimic the collagen fibril diameter distribution of healthy and damaged ACL. In
terms of biomechanical characteristics, native ACL tissue outperformed PCL scaffolds.
Aligned bimodal scaffolds exhibited improved mechanical properties as compared to
unaligned unimodal PCL scaffolds.
This study is novel because we demonstrated, for the first time, the collagen fibril
diameter distribution of healthy and injured ACL tissues harvested from sheep.
Additionally, we propose a method for fabrication of scaffolds that mimic the collagen fibril diameter distribution of healthy and injured ACL. The study’s significance relies on the
fact that it addresses an important clinical problem related to orthopedics that concerns
millions of patients worldwide. The fibrous scaffold design proposed here deviates from
the traditional unimodal technique, and it is anticipated to have a substantial impact on
ACL regeneration efforts.
Keywords: ACL, PCL, tissue engineering, nanosized fibers, biomimicry, ligament
scaffold, polymer fiber-based fibers, electrospinning, mesenchymal stem cells.
Description
Keywords
Type of access: Open Access, ACL, PCL, tissue engineering, nanosized fibers, biomimicry, ligament scaffold, polymer fiber-based fibers, electrospinning, mesenchymal stem cells, Research Subject Categories::TECHNOLOGY
Citation
"Smatov, S. (2021). POLYCAPROLACTONE BASED NANOFIBER SCAFFOLDS CAN MIMIC COLLAGEN FIBRIL DIAMETER DISTRIBUTION OF HEALTHY AND INJURED SHEEP ANTERIOR CRUCIATE LIGAMENT (Unpublished master's thesis). Nazarbayev University, Nur-Sultan, Kazakhstan"