Regenerative and Resorbable PLA/HA Hybrid Construct for Tendon/Ligament Tissue Engineering.

Tendon and ligament shows extremely limited endogenous regenerative capacity. Current treatments are based on the replacement and or augmentation of the injured tissue but the repaired tissue rarely achieve functionality equal to that of the preinjured tissue. To address this challenge, tissue engineering has emerged as a promising strategy. This study develops a regenerative and resorbable hybrid construct for tendon and ligament engineering. The construct is made up by a hollow poly-lactic acid braid with embedded microspheres carrying cells and an anti-adherent coating, with all the parts being made of biodegradable materials. This assembly intends to regenerate the tissue starting from the interior of the construct towards outside while it degrades. Fibroblasts cultured on poly lactic acid and hyaluronic acid microspheres for 6 h were injected into the hollow braid and the construct was cultured for 14 days. The cells thus transported into the lumen of the construct were able to migrate and adhere to the braid fibers naturally, leading to a homogeneous proliferation inside the braid. Moreover, no cells were found on the outer surface of the coating. Altogether, this study demonstrated that PLA/HA hybrid construct could be a promising material for tendon and ligament repair.

Positioning of the cross-stitch on the modified Kessler core tendon suture.

Cryopreserved human tendons were sutured with different variations of a modified Kessler-type grasping suture in a series of different designs in order to assess the influence of the distance between the cross-stitch on the core suture (5 and 10 mm from the cut tendon edge) on the peripheral suture. An original mathematical model was employed to explain the mechanical behavior (strength, deformation, and distribution of load) of the different suture designs. The effect of the peripheral epitendinous suture, combined with the distance of the core suture, was evaluated. The variation of core suture distance had no relevant consequences on the overall resilience of the design. However, increasing the distance between the cross-stitches of the core suture reduces the deformation that is absorbed not only by the core suture itself but also by the peripheral suture. Adding a peripheral epitendinous suture to a 10-mm design almost doubles the breaking load in absolute values. The mathematical model predicts that the peripheral suture will support a greater load when the distance of the core suture cross-stitches is increased. The evidence level is II.