Laboratory of Biomaterials and Polymers of Specialty, UMR CNRS 7244, Institut Galilée, Université Paris 13, Sorbonne Paris Cité, Villetaneuse, France.
Laboratory of Biomechanics and Bioengineering, UMR CNRS 7338, Sorbonne Universités, Université de Technologie de Compiègne, Compiègne, France.
PLoS One. 2018 Oct 11;13(10):e0205722. doi: 10.1371/journal.pone.0205722. eCollection 2018.
The anterior cruciate ligament rupture is one of the most common sport injuries. Due to ligaments' poor healing capacity, surgical intervention is often required. Nowadays, these injuries are managed using replacement autografts or to a lesser extent using artificial ligaments. With the expansion of tissue engineering, more recent researches focus on the development of biodegradable structures that could allow graft functioning while enhancing host integration. The main challenge is to develop a structure that gradually loses its mechanical properties when at the same time the neo-ligament gains in solidity. Mechanical behavior and reconstruction of natural tissue are the two key points for such a successful device. This article evaluates the mechanical consistency of poly(ε-caprolactone) fibers bundles grafted with sodium polystyrene sulfonate, as a candidate for ligament prosthesis. In order to be medically used, PCL fibers need to cope with multiple steps before implantation including extensive washings, knitting, grafting and sterilization processes. The evolution of mechanical properties at each step of the elaboration process has been investigated. The results show that PCL bundles have the same visco-elastic behavior than the native ACL. Nevertheless, when undergoing physical treatments such as ionizing radiations, like UV or β-rays, the material endures a hardening, increasing its stiffness but also its fragility. At this opposite, the thermal radical grafting acts like an annealing step, increasing significantly the elasticity of the PCL fibers. With this chemical treatment, the stiffness is decreasing, leading to higher energy dissipation. Added to the observation of the structure of the material, this demonstrates the possibility of the PCL to modulate it microstructure. In case of orthopedic prosthesis, the need of such a construct is strongly required to avoid distension of the future prosthesis and to restore good knee stabilization, showing the promising future of PCL ligament prosthesis.
前交叉韧带撕裂是最常见的运动损伤之一。由于韧带愈合能力差，通常需要手术干预。如今，这些损伤采用替代自体移植物或在较小程度上采用人工韧带进行治疗。随着组织工程学的发展，最近的研究更多地集中在开发可生物降解的结构上，这些结构可以在增强宿主整合的同时允许移植物发挥作用。主要的挑战是开发一种结构，使其机械性能逐渐丧失，同时新的韧带获得坚固性。机械性能和重建天然组织是此类成功装置的两个关键要点。本文评估了用聚苯乙烯磺酸钠接枝的聚己内酯纤维束作为韧带假体的候选物的机械一致性。为了在医学上使用，PCL 纤维在植入前需要经过多个步骤，包括广泛的清洗、编织、移植和消毒过程。已经研究了在制备过程的每个步骤中机械性能的演变。结果表明，PCL 束具有与天然 ACL 相同的粘弹性行为。然而，当经历物理处理如电离辐射，如紫外线或β射线时，材料会经历硬化，增加其刚度但也使其易碎。相反，热自由基接枝作用类似于退火步骤，显著提高了 PCL 纤维的弹性。通过这种化学处理，刚度降低，导致能量耗散增加。除了观察材料的结构外，这证明了 PCL 调节其微观结构的可能性。在矫形假体的情况下，强烈需要这种结构来避免未来假体的扩张并恢复良好的膝关节稳定性，这表明 PCL 韧带假体具有广阔的前景。
