Cell‐laden composite suture threads for repairing damaged tendons

Abstract

Tendons have limited regenerative capacity due to their low cellularity and hypovascular nature, which results in poor clinical outcomes of presently used therapies. As tendon injuries are often observed in active adults, it poses an increasing socio-economic burden on healthcare systems. Currently, suture threads are used during surgical repair to anchor the tissue graft or to connect injured ends. Here, we created composite suture threads coated with a layer of cell-laden hydrogel that can be used for bridging the injured tissue aiming at tendon regeneration. In addition, the fibres can be used to engineer 3-dimensional constructs through textile processes mimicking the architecture and mechanical properties of soft tissues, including tendons and ligaments. Encapsulated human tendon-derived cells migrated within the hydrogel and aligned at the surface of the core thread. An up-regulation of tendon-related genes (scleraxis and tenascin C) and genes involved in matrix remodelling (matrix metalloproteinases 1, matrix metalloproteinases 2) was observed. Cells were able to produce a collagen-rich matrix, remodelling their micro-environment, which is structurally comparable to native tendon tissue.

Fibre-based scaffolding techniques for tendon tissue engineering

“…(m) Fabrication process of composite living fibres, in which a biocompatible thread was passed through the baths and was collected by the motor, leading to the formation of a cell‐laden hydrogel layer on the thread (Akbari et al, ). (b, d, f, h, j, l, n) Images of fibre or fibre bundle manufactured using related techniques (An et al, ; Costa‐Almeida et al, ; Kew et al, ; Tamura et al, ; Wu, Wang, et al, ; Yin et al, ; Younesi et al, ) [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…Threads were pulled through a sequence of baths containing CaCl 2 and alginate mixed with cells using a spool, and the thickness of coating layer could be adjusted (Figure m). This method has been further explored by Costa‐Almeida et al () for tendon TE. The hydrogel layer of alginate and GelMA that loaded with human tendon cells was coated on braided surgical suturing threads (Figure n).…”

“…(m) Fabrication process of composite living fibres, in which a biocompatible thread was passed through the baths and was collected by the motor, leading to the formation of a cell-laden hydrogel layer on the thread (Akbari et al, 2014). (b, d, f, h, j, l, n) Images of fibre or fibre bundle manufactured using related techniques Costa-Almeida et al, 2017;Kew et al, 2012;Tamura et al, 2002;Wu, Wang, et al, 2015;Yin et al, 2010;Younesi et al, 2014) [Colour figure can be viewed at wileyonlinelibrary.com] more than one materials onto the collector. As a composite scaffold, PCL fibres of 1.2 μm and chitosan fibres of 360 nm were coelectrospun for treatment of rotator cuff tears by Zhao et al (2015).…”

Tendon Tissue Engineering: Effects of Mechanical and Biochemical Stimulation on Stem Cell Alignment on Cell‐Laden Hydrogel Yarns

“…However, they do not guarantee full recovery and suffer from many disadvantages such as donor site morbidity, low availability, inflammatory response, and infection risk . To overcome the limitations of the existing treatment methods, researchers have introduced innovative tissue engineered scaffolds incorporating cells and growth factors as well as constructs that simulate the fibrous structure of tendon . Numerous strategies exist based on fiber‐forming techniques, such as electrospinning .…”

Exploring platelet lysate hydrogel-coated suture threads as biofunctional composite living fibers for cell delivery in tissue repair

“…One of the most attractive features of CLF is the possibility of tuning the properties of each compartment independently. We have further developed composite suture threads based on CLF biofabrication concept by coating commercial silk sutures with a hydrogel composed of alginate and methacrylated gelatin (ALG:GelMA) [13]. After encapsulating human tendon derived cells (hTDCs), we have demonstrated cell migration and alignment, as well as up-regulation of genes associated with tenogenesis and matrix remodeling [13].…”