Over the past decades, anterior cruciate ligament injuries have become a considerable public health issue. Due to specific physiological conditions such injuries often demand replacement surgery and can take up to two years to a complete recovery. Using biomaterials able to accelerate the healing process could represent a remarkable progress in the field. The main goal of this article is, therein, to evaluate the mechanical properties of poly(ε-caprolactone) (PCL) fibers with biological properties enhanced by poly(sodium styrene sulfonate) (PNaSS) grafting when subjected to mechanical stress in different conditions.

PCL fibers were thermal grafted with PNaSS. The grafting density was estimated by the toluidine blue colorimetric assay (TB). The influence of the grafting on in vitro primary ACL fibroblast behavior was evaluated by cell proliferation and fluorescence microscope images. The mechanical behavior was evaluated by tensile experiments in air and water, fatigue experiments and simulated walk efforts.

The results show that poly(ε-caprolactone) bundles have their mechanical behavior changed by the different surface treatments and nature of mechanical stress. Although, compared with the values of the natural ligament, the poly(ε-caprolactone) has shown superior mechanical properties (Young's Modulus, elastic deformation and ultimate tensile stress) in all studied scenarios. In addition, the pNaSS-grafted surfaces presented a positive influence in the cell proliferation and morphology.

The pNaSS-grafted PCL has responded mechanical and biological requests for suitable ligament prosthesis material and could be considered as a promising alternative for ACL reconstruction.