A nucleus implant is disclosed. The nucleus implant can be configured to be installed within an intervertebral disc between an inferior vertebra and a superior vertebra. The nucleus implant can include an expandable core and an expandable chamber that can be disposed at least partially around the expandable core. The expandable chamber can be expanded from a deflated position to an inflated position. Further, a hardness of the expandable core when inflated can greater than or equal to a hardness of the expandable chamber when inflated.