Nucleus pulposus replacement

Patent Pending Nucleus pulposus is the gel-like substance in the middle of the spinal disc. It is the remnant of the notochord. It functions to distribute hydraulic pressure in all directions within each disc under compressive loads. The nucleus pulposus consists of large vacuolated notochord cells, small chondrocyte-like cells, collagen fibrils, and proteoglycan aggrecans that aggregate through hyaluronic chains. Attached to each aggrecan molecule are the glycosaminoglycan (GAG) chains of chondroitin sulfate and keratan sulfate. Aggrecan is negatively charged, allowing the nucleus pulposus to attract water molecules. The amount of water and glycosaminoglycans decreases with age and degeneration.