Composite tissue-engineered intervertebral disc with self-assembled annular alignment

A method of fabricating a tissue-engineered intervertebral disc (IVD) suitable for total disc replacement in a mammal, said method comprising:

• providing a first gel comprising a first population of living cells that secrete a hydrophilic protein;
• forming the first gel into a predetermined shape and size;
• providing a second different gel comprising a second different population of living cells and collagen;
• contacting the formed first gel with the second gel at a region that extends circumferentially around the first gel;
• and
• storing the first and second gels under conditions effective for the collagen in the second gel to align circumferentially around the first gel by self-assembly of collagen due to cell-mediated gel contraction in the second gel, wherein the first gel forms a nucleus pulposus structure and the second gel forms an annulus fibrosus structure surrounding and in contact with the nucleus pulposus structure, thereby fabricating a tissue-engineered IVD suitable for total disc replacement in a mammal.