Biological fixation of fibrous materials to bone using chitin/chitosan as a bone formation accelerator

Biological fixation or anchorage of fibrous materials to bone by bone ingrowth into the spaces between fibers is a major concern in developing novel medical implants, including artificial ligaments. Toward this end, we evaluated the efficacy of chitin/chitosan as a bone formation accelerator. Specimens of polyester nonwoven fabric coated with chitin/chitosan were implanted into holes drilled into the distal ends of rat femora. Uncoated fabric specimens were used as controls. At 1 or 2 weeks after implantation, the specimens were retrieved, and the fixation strength was measured by mechanical testing. Histological sections of 2-week implantation specimens were prepared, and the area of new bone tissue formed in the spaces between the fibers of the fabric was measured. The chitin/chitosan coating significantly increased the fixation strength and the area of bone tissue formed in the spaces between the fibers. The mean fixation strength of chitin/chitosan-coated fabric specimens was more than twice that of the controls at 2 weeks after implantation. These results demonstrated that the chitin/chitosan coating effectively induced bone formation in the spaces between the fibers and enhanced biological fixation of the fibrous materials to the bone.