StarPEG/heparin-hydrogel based in vivo engineering of stable bizonal cartilage with a calcified bottom layer

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Elke Kunisch - , Heidelberg University  (Author)
  • Anne Kathrin Knauf - , Heidelberg University , Leipzig University (Author)
  • Eliane Hesse - , Heidelberg University  (Author)
  • Uwe Freudenberg - , Leibniz Institute of Polymer Research Dresden (Author)
  • Carsten Werner - , Chair of Biofunctional Polymer Materials, Leibniz Institute of Polymer Research Dresden (Author)
  • Friederike Bothe - , Heidelberg University  (Author)
  • Solvig Diederichs - , Heidelberg University  (Author)
  • Wiltrud Richter - , Heidelberg University  (Author)

Abstract

Repaired cartilage tissue lacks the typical zonal structure of healthy native cartilage needed for appropriate function. Current grafts for treatment of full thickness cartilage defects focus primarily on a nonzonal design and this may be a reason why inferior nonzonal regeneration tissue developed in vivo. No biomaterial-based solutions have been developed so far to induce a proper zonal architecture into a non-mineralized and a calcified cartilage layer. The objective was to grow bizonal cartilage with a calcified cartilage bottom zone wherein main tissue development is occurring in vivo. We hypothesized that starPEG/heparin-hydrogel owing to the glycosaminoglycan heparin contained as a building-block would prevent mineralization of the upper cartilage zone and be beneficial in inhibiting long-term progression of calcified cartilage into bone. MSCs were pre-cultured as self-assembling non-mineralized cell discs before a chondrocyte-seeded fibrin-or starPEG/heparin-hydrogel layer was cast on top directly before ectopic implantation. Bizonal cartilage with a calcified bottom-layer developed in vivo showing stronger mineralization compared to in vitro samples, but the hydrogel strongly determined outcome. Zonal fibrin-constructs lost volume and allowed non-organized expansion of collagen type X, ALP-activity and mineralization from the bottom-layer into upper regions, whereas zonal starPEG/heparin-constructs were of stable architecture. While non-zonal MSCs-derived discs formed bone over 12 weeks, the starPEG/heparin-chondrocyte layer prevented further progression of calcified cartilage into bone tissue. Conclusively, starPEG/heparin-hydrogel-controlled and cell-type mediated spatiotemporal regulation allowed in vivo growth of bizonal cartilage with a stable calcified cartilage layer. Altogether our work is an important milestone encouraging direct in vivo growth of organized cartilage after biofabrication.

Details

Original languageEnglish
Article number015001
JournalBiofabrication
Volume11
Issue number1
Publication statusPublished - Jan 2019
Peer-reviewedYes

External IDs

PubMed 30376451
ORCID /0000-0003-0189-3448/work/161890321

Keywords

Keywords

  • Calcified cartilage, Chondrocyte, Hydrogel, Layered construct, Mesenchymal stroma cells