PolyNaSS bioactivation of LARS artificial ligament promotes human ligament fibroblast colonisation in vitro.

BACKGROUND: Introduction of a new generation of artificial ligaments for ACL reconstruction, the Ligament Augmentation and Reconstruction System (LARS), gives promising clinical results [1]. The current literature supports the use of LARS from short to medium term. To go even further to improve the biocompatibility of this biomaterial, poly(sodium styrene sulfonate) (polyNaSS) was grafted onto its surface. Studies using sheep animal model showed improvement of knee functionalities with this grafted artificial ligament and a better adhesion of human cell lines.

OBJECTIVES: To better understand this in vivo improvement of integration with the bioactivated artificial prosthesis, in vitro studies were leaded using human ligament fibroblasts.

METHODS: Human ligament fibroblasts isolated from human ruptured ACL were amplified and seeded onto poly(NaSS) grafted and non-grafted PET scaffold (Lars ligament) under standard culture conditions. Cellularized fibers were observed under scanning electron microscopy and histological and immunohistological studies were performed.

RESULTS: Cells are localized around the grafted PET fibers of the bioactive ligament and penetrate in the scaffold. On ungrafted fibers, cells stay around the scaffold. On grafted fibers, collagen I appears strongly organized whereas is thin and dispersed on non grafted fibers. Finally, grafting altered localization of decorin.

CONCLUSIONS: PolyNaSS grafting enhances human ligament fibroblast organisation in vitro in contact with biomaterial and improves collagen and decorin deposits around fibers.