Combining electrospinning and cell sheet technology for the development of a multiscale tissue engineered ligament construct (TELC)

Abstract

Ligament tissue rupture is a common sport injury. Although current treatment modalities can achieve appropriate reconstruction of the damaged ligament, they present significant drawbacks, mostly related to reduced tissue availability and pain associated with tissue harvesting. Stem cell based tissue regeneration combined with electrospun scaffolds represents a novel treatment method for torn ligaments. In this study, a low fiber density polycaprolactone (PCL) electrospun mesh and sheep mesenchymal stem cells (sMSCs) were used to develop tissue engineered ligament construct (TELC) in vitro. The assembly of the TELC was based on the spontaneous capacity of the cells to organize themselves into a cell sheet once seeded onto the electrospun mesh. The cell sheet matured over 4 weeks and strongly integrated with the low fiber density electrospun mesh which was subsequently processed into a ligament-like bundle and braided with two other bundles to develop the final construct. Live/dead assay revealed that the handling of the construct through the various phases of assembly did not cause significant difference in viability compared to the control. Mechanical evaluation demonstrated that the incorporation of the cell sheet into the braided construct resulted in significantly modifying the mechanical behavior. A stress/displacement J-curve was observed for the TELC that was similar to native ligament, whereas this particular feature was not observed in the non-cellularized specimens. The regenerative potential of the TELC was evaluated ectopically in immunocompromized rats, compared to non cellularized electrospun fiber mesh and this demonstrated that the TELC was well colonized by host cells and that a significant remodelling of the implanted construct was observed.

Additively Manufactured Multiphasic Bone–Ligament–Bone Scaffold for Scapholunate Interosseous Ligament Reconstruction

“…In addition, cell sheet technology has been applied to the regeneration of various tissues and organs, such as for the heart, liver, cornea, periodontal ligament, esophagus, and musculoskeletal applications . In particular, this technology has been utilized for orthopedic applications to create both scaffold‐based and scaffold‐free cellularized constructs. Orthopedic applications such as anterior cruciate ligament replacement have been at the forefront of cell sheet utilization, either combined with knitted structures, or simply created by stacking cell sheets and allowing their fusion in vitro prior to implantation 10c.…”

Biofabrication of Electrospun Scaffolds for the Regeneration of Tendons and Ligaments

“…The mats were seeded with BMMSCs for four weeks and finally subcutaneously implanted in an in vivo rat model to evaluate the biocompatibility. While the biocompatibility and cell proliferation were promising, the mechanical properties after four weeks of static culture were significantly lower than the as-spun controls (average control failure load = 0.7 N; average four weeks scaffold failure load = 0.3 N) [ 94 ].…”

Advanced Bottom‐Up Engineering of Living Architectures

“…Monolayer cell sheets are built with millions of cells, but their sheet‐like fragile structure is hard to manipulate and does not offer enough microtissue depth in comparison to thick native tissues . However, researchers can assemble thicker constructs just by stacking cell sheets, taking advantage of the cell‐dense vast ECM network that naturally intertwines the different cell sheets into a contiguous and integral multilayered microtissue .…”