Collagen hybridization with poly(l-lactic acid) braid promotes ligament cell migration

The purpose of this study is to evaluate the cellular response to a poly(l-lactic acid) (PLLA)-collagen hybrid scaffold for ligament regeneration based on tissue engineering. A three-dimensional (four-axis) braid with a diameter of 2.5 mm was made from PLLA filaments. The braid was further hybridized with bovine type I collagen to prepare the PLLA-collagen hybrid braid. Cellular responses of ligament cells to the PLLA and PLLA-collagen hybrid braids were evaluated both in vitro and in vivo. More cells and more homogeneous cell distribution were observed in vitro in the hybrid braid than in the PLLA braid. More fibroblast immigration and neo-angiogenesis were detected in the hybrid braid than in the PLLA braid when implanted on ruptured medial collateral ligament (MCL). Hybridization with collagen facilitated cell seeding and spatial cell distribution, and promoted cell immigration and neo-angiogenesis. The hybrid braid would be useful for ligament tissue engineering.