Engineering hybrid textile braids for tendon and ligament repair application

Abstract

Challenges involving tendon and ligament repair have motivated the investigation of new strategies to improve clinical outcomes. These have been mainly based on polymer constructs, which may be non-biodegradable or biodegradable. The former typically fails due to lack of device integration and the latter demands a complex balance between biodegradability and tissue ingrowth, often failing due to insufficient mechanical properties. This work presents the development of hybrid braids based on polyethylene terephthalate (PET) and polylactic acid (PLA) yarns. A textile technique was used to fabricate braids based on 16 multifilament yarns of varying PLA/PET composition. The composition was varied to maximize biodegradability while ensuring mechanical performance. The braids' morphology, physical and mechanical properties were characterized. As production parameters and architecture were maintained, the braids exhibited similar porosity and wicking ability. The breaking force and stiffness decreased significantly as the number of PLA yarns increased, although strain levels remained constant. Braids containing 10 and 12 PET yarns (out of the total 16 yarns) demonstrated good creep and force-relaxation behavior, as well as resistance to cyclic loading. These compositions were selected for future work, to be assembled into more elaborate structures to mimic the fibrous organization and tensile properties of different tendons/ ligaments.

Hybrid structures for Achilles' tendon repair

“…27 Our group has previously described the production of individual braids made from PET and PLA multifilament yarns, where various PET:PLA compositions were tested. 28 The present work proposes a medical device based on the compositions that had previously presented the most promising mechanical properties. For that, different braids were used as elementary parts and gathered into intricate constructs that mimic the fibrous architecture and tensile mechanical behavior of the native tissue.…”

Amination of Polymeric Braid Structures to Improve Tendon Healing: An Experimental Comparison

“…An innovative medical device produced from hybrid textile braids based on PET and PLA yarns was developed in a previous work. [8,9] The designed device presents a core-shell architecture (several hybrid braids surrounded by an exterior shell of braided PET yarns) that mimics the hierarchical morphological features and fulfills the high mechanical demands of tissues such as tendons and ligaments. During the first phase of the repair process, the non-degradable component (PET) protects the cells and newly formed tissue from excessive strains by withstanding physiological loads and providing mechanical support, allowing the body's natural healing process to take place.…”

“…Hybrid braids with a higher PET to PLA ratio demonstrated suitable mechanical properties for the intended purpose. [8,9] As such, the primary purpose of this work was to surface modify the PET yarns, which are present in higher number in the hybrid medical device. PLA was also functionalized to evaluate the impact of the surface modification process on the performance of the hybrid medical device.…”

Current Concepts and Methods in Tissue Interface Scaffold Fabrication

“…Tendons are responsible for transferring forces from muscle to bone and are critical for joint mobility and stability [ 65 ]. Overall, tendons have a low capacity to heal, primarily due to a lack of blood supply.…”

“…The current gold standard of treatment following tendon injury involves surgery which may include suturing the ends of the ruptured tissue. In more complex cases, inclusion of a tendon graft may be required to provide a base material to initiate repair [ 65 ]. These treatment options possess disadvantages including insufficient mechanical stability, as well as a risk of graft failure [ 69 ].…”