Intervertebral Disc Regeneration Injection of a Cell-Loaded Collagen Hydrogel in a Sheep Model

• Published in: International journal of molecular sciences 2021-04, Vol.22 (8), p.4248
• Main Authors: Friedmann, Andrea, Baertel, Andre, Schmitt, Christine, Ludtka, Christopher, Milosevic, Javorina, Meisel, Hans-Joerg, Goehre, Felix, Schwan, Stefan
• Format: Article
• Language: English
• Subjects: adipose stem cell; Adipose tissue; Animals; Autografts; Biomechanics; Bone marrow; Cell growth; Collagen; Collagen - administration & dosage; Collagen - therapeutic use; collagen hydrogel; Degeneration; Degenerative disc disease; Disease Models, Animal; Female; Histology; Hydrogels; Hydrogels - chemistry; Injection; Intervertebral Disc - surgery; Intervertebral Disc Degeneration - surgery; intervertebral disc regeneration; Intervertebral discs; Investigations; Model testing; ovine model; Physiology; regenerative medicine; Regenerative Medicine - methods; Scaffolds; Sheep; Stem cells; Tissue engineering; Transplants & implants
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22084248

Degenerated intervertebral discs (IVDs) were treated with autologous adipose-derived stem cells (ASC) loaded into an injectable collagen scaffold in a sheep model to investigate the implant's therapeutic potential regarding the progression of degeneration of previously damaged discs. In this study, 18 merino sheep were subjected to a 3-step minimally invasive injury and treatment model, which consisted of surgically induced disc degeneration, treatment of IVDs with an ASC-loaded collagen hydrogel 6 weeks post-operatively, and assessment of the implant's influence on degenerative tissue changes after 6 and 12 months of grazing. Autologous ASCs were extracted from subcutaneous adipose tissue and cultivated in vitro. At the end of the experiment, disc heights were determined by µ-CT measurements and morphological tissue changes were histologically examined.Histological investigations show that, after treatment with the ASC-loaded collagen hydrogel implant, degeneration-specific features were observed less frequently. Quantitative studies of the degree of degeneration did not demonstrate a significant influence on potential tissue regeneration with treatment. Regarding disc height analysis, at both 6 and 12 months after treatment with the ASC-loaded collagen hydrogel implant a stabilization of the disc height can be seen. A complete restoration of the intervertebral disc heights however could not be achieved.The reported injection procedure describes in a preclinical model a translational therapeutic approach for degenerative disc diseases based on adipose-derived stem cells in a collagen hydrogel scaffold. Further investigations are planned with the use of a different injectable scaffold material using the same test model.