Gelexir Material

  • Resulting from the collaboration of the two scientific founders, Pr. A Freemont and Pr. B Saunders, the development of the Gelexir biomaterial has been in progress at the University of Manchester since the late 1990’s, initially with research into the degenerative processes of the IVDs nucleus pulposus cells and later with the parallel development of a designer biomaterial . This has resulted in the filing of key international patents and numerous publications.
  • The Gelexir approach uses singly cross-linked (SX) poly(methylmethacrylate)-based microgel dispersions. (SX is used here to highlight cross-linking that occurs within the microgel particles.) The SX microgel is an injectable fluid similar to most of the standard hydrogels.
  • To overcome the limitations of most of physically gelled microgel dispersions flowing under shear and re-dispersing in water, a method has been established to covalently interlink physically gelled microgel dispersions.
  • Our approach provides pH-responsive hydrogels comprised of microgels that are doubly cross-linked (DX) to cure upon injection into the disc. (DX Microgel is used to designate the second cross-linking occurring between the microgel particles).
  • Upon injection, the pH increases making the microgels expand by absorbing water. As microgel-particles expand, the linking molecules on their surface connect with other linking molecules from the neighbouring microgel particles. The swollen inter-linked microgels form from a space-filling a load-bearing material.
  • The SX/DX Microgel has successfully passed all the European / US standardised tests to assess biocompatibility (ISO 10993) and Biomechanical performance (ISO 18192). In vivo data from sheep confirmed the excellent tolerance of the injected gel.