Gelatin methacryloyl hydrogel with and without dental pulp stem cells for TMJ regeneration: An in vivo study in rabbits

J Oral Rehabil. 2024 Feb;51(2):394-403. doi: 10.1111/joor.13608. Epub 2023 Oct 13.

Abstract

Background: In the last decade, tissue-engineering strategies for regenerating the temporomandibular joint (TMJ) have been investigated. This may be a promising strategy for the minimally invasive restoration of joint integrity.

Objectives: To evaluate whether dental pulp stem cells (DPSCs) loaded in a light-occured hydrogel made of gelatin methacryloyl (GelMA) enhance the regeneration of osteochondral defects in the rabbit TMJ.

Materials and methods: Defects were filled with GelMA alone (control group; n = 4) or filled with GelMA loaded with rabbit DPSCs (experimental group; n = 4), In one group, the TMJ capsule was opened without creating a defect (sham group; n = 2). The following micro-CT parameters were analysed: bone volume to total volume ratio (BV/TV%) and bone mineral density (BMD). Histological evaluation was performed to assess cartilage regeneration features. A semi-quantitative scoring system was also used to evaluate the defects.

Results: All groups had no statistical difference regarding the micro-CT parameters. The highest mean healing score was found for the experimental group. After 4 weeks, there were no signs of hydrogel in either group or no signs of inflammation in the adjacent tissues. The tissue formed in the defect was dense fibrous connective tissue.

Conclusion: Adding DPSCs to GelMA did not provide a regenerative enhancement in TMJ osteochondral defects. This resulted in similar micro-CT parameters after 4 weeks of healing, with improved signs of subchondral bone regeneration but no cartilage regeneration.

Keywords: animal model; biocompatible materials; cartilage; mandibular condyle; regenerative medicine; tissue scaffolds.

MeSH terms

  • Animals
  • Dental Pulp*
  • Hydrogels*
  • Rabbits
  • Stem Cells
  • Temporomandibular Joint
  • Tissue Engineering / methods

Substances

  • Hydrogels
  • gelatin methacryloyl