Long-term hydrolytic degradation study on polymer-based embroidered scaffolds for ligament tissue engineering

Abstract

Following anterior cruciate ligament injury, a mechanically stable tissue replacement is required for knee stability and to avoid subsequent damages. Tissue engineering of the anterior cruciate ligament demands a biocompatible scaffold with a controllable degradation profile to provide mechanical support for 3 to 6 months. It has been argued that embroidered textile scaffolds made of polylactic acid and poly(lactic-co-ɛ-caprolactone) fibres are a promising approach for the ligament tissue engineering with an adapted functionalization and cell seeding strategy. Therefore, the hydrolytic degradation behaviour of embroidered scaffolds made of polylactic acid and a combination of polylactic acid and poly(lactic-co-ɛ-caprolactone) fibres was investigated under physiological conditions for 168 days. The changes in the mechanical behaviour, the molecular weights as well as the surface structures were analysed. Sufficient mechanical properties comparable to native anterior cruciate ligament tissue could be demonstrated for scaffolds made of polylactic acid fibres after 6 months under hydrolysis. These results clarify the potential of using embroidered scaffolds for ligament tissue engineering.

Enhanced Growth of Lapine Anterior Cruciate Ligament-Derived Fibroblasts on Scaffolds Embroidered from Poly(l-lactide-co-ε-caprolactone) and Polylactic Acid Threads Functionalized by Fluorination and Hexamethylene Diisocyanate Cross-Linked Collagen Foams

“…P(LA-CL) has been recommended for ACL tissue engineering [11]. The advantage of these materials is that they are cytocompatible [12,13], degradable over a sufficient long period of time as well as stable enough and suitable for the embroidery process [14]. Embroidered structures have promising biomechanical properties and are suited for colonization with lapine ACL (LACL)-derived fibroblasts [13,15].…”

Viscoelastic Behavior of Embroidered Scaffolds for ACL Tissue Engineering Made of PLA and P(LA-CL) After In Vitro Degradation

“…There were no significant differences in the mechanical values when comparing dry state and degraded state after 14 and 28 days, respectively (Figure 9). Additionally, the values of UTL, UTE and S were comparable to values of unseeded scaffolds after similar degradation periods under hydrolytic conditions [32].…”

“…Ultimate tensile load (UTL in N), ultimate tensile elongation (UTE in %), and stiffness (S in N/mm) were determined according to Hahner et al (2015) [27]. Values for completely non-preconditioned embroidered scaffolds after hydrolytic long-term degradation can be taken from Hahn et al (2017) [32] for comparison. A possible influence of certain preloading conditions on the characteristic maximum values of the scaffolds shall be pointed out based on the presented data.…”

“…As long as the pre-treatment remains within the elastic deformation range of the scaffolds, there seems to be no influence on the ultimate tensile properties. Nevertheless, the increase in stiffness values during degradation, especially for the moco scaffolds, was also mentioned [32]. Besides, no significant changes in UTL, UTE, and S values appeared for the in vitro degraded scaffolds, compared to the non-degraded and the hydrolytically degraded ones over 28 days, irrespective of different treatment by fluorination.…”

“…There were no significant differences in the mechanical values between the test group A without and test group B with preconditioning. The long-term hydrolytic degradation behavior of the embroidered structures made of PLA and P(LA-CL) was analyzed with regards to their ultimate tensile properties, molecular weights, as well as surface structure changes demonstrated by SEM images; the results were previously published [32]. In comparison, the mechanical testing was performed without any preconditioning.…”