The effect of pNaSS grafting of knitted poly(ε-caprolactone) artificial ligaments on in vitro mineralization and in vivo osseointegration

Abstract

Augmenting anterior cruciate ligament (ACL) repair using synthetic scaffolds to promote ligament healing is a new emerging surgical strategy for the treatment of ruptured ACL. Osseointegration of such scaffolds is critical, as the lack of osseointegration may lead to bone tunnel widening and joint instability.This study aimed to evaluate osseointegration of a new poly(ε-caprolactone) (PCL)-knitted artificial ligament and the potential benefits of its functionalization with the grafting of a bioactive polymer, the polystyrene sodium sulfonate (pNaSS), on bone incorporation.In vitro assays showed that the functionalization of PCL substrates positively impacted pre-osteoblasts proliferation and differentiation through superior alkaline phosphatase activity and higher calcium deposition. Implantation of pNaSS-grafted PCL ligaments for 12 weeks in a rat model of ACL repair augmentation, using non-grafted PCL ligaments and tendinous autograft as control conditions, showed enhanced osseointegration of autografts and grafted PCL ligaments compared to non-grafted ligaments. These results open up new avenues to improve osseointegration of PCL ligaments designed for ACL repair.