Ligament tissue engineering using synthetic biodegradable fiber scaffolds

Tissue engineering offers the possibility of replacing damaged human ligaments with engineered ligament tissues. Hence, we attempted to culture in vitro ligament tissues by seeding human anterior cruciate ligament (ACL) and medial collateral ligament (MCL) cells onto synthetic biodegradable polymer fiber scaffolds. The ACL and MCL cells readily attached to the scaffold fibers. These cells and their secreted matrix soon surrounded the scaffold fibers and bridged the gaps in between. Beginning at 2 weeks, portions of the scaffolds were completely filled with tissue matrix. By 5 weeks, the scaffolds became single bundles of tissue. Thus the cell/fiber system appears to be a viable system for culturing ligament tissues. Additionally, cell proliferation under mechanical and biochemical stimuli was studied for up to 4 days. Whereas mechanical stimulus and transforming growth factor enhanced proliferation, inflammatory agents (lipopolysaccharide and complement C5a) had a negative effect. This work can thus contribute to a sound strategy for culturing replacement ligament tissues in vitro.