title: Investigation of different cell types and gel carriers for cell-based intervertebral disc therapy, in vitro and in vivo studies.
abstract: Biological treatment options for the repair of intervertebral disc damage have been suggested for patients with chronic low back pain. The aim of this study was to investigate possible cell types and gel carriers for use in the regenerative treatment of degenerative intervertebral discs (IVD). In vitro: human mesenchymal cells (hMSCs), IVD cells (hDCs), and chondrocytes (hCs) were cultivated in three gel types: hyaluronan gel (Durolane®), hydrogel (Puramatrix®), and tissue-glue gel (TISSEEL®) in chondrogenic differentiation media for 9 days. Cell proliferation and proteoglycan accumulation were evaluated with microscopy and histology. In vivo: hMSCs or hCs and hyaluronan gel were co-injected into injured IVDs of six minipigs. Animals were sacrificed at 3 or 6 months. Transplanted cells were traced with anti-human antibodies. IVD appearance was visualized by MRI, immunohistochemistry, and histology. Hyaluronan gel induced the highest cell proliferation in vitro for all cell types. Xenotransplanted hMSCs and hCs survived in porcine IVDs for 6 months and produced collagen II in all six animals. Six months after transplantation of cell/gel, pronounced endplate changes indicating severe IVD degeneration were observed at MRI in 1/3 hC/gel, 1/3 hMSCs/gel and 1/3 gel only injected IVDs at MRI and 1/3 hMSC/gel, 3/3 hC/gel, 2/3 gel and 1/3 injured IVDs showed positive staining for bone mineralization. In 1 of 3 discs receiving hC/gel, in 1 of 3 receiving hMSCs/gel, and in 1 of 3 discs receiving gel alone. Injected IVDs on MRI results in 1 of 3 hMSC/gel, in 3 of 3 hC/gel, in 2 of 3 gel, and in 1 of 3 injured IVDs animals showed positive staining for bone mineralization. The investigated hyaluronan gel carrier is not suitable for use in cell therapy of injured/degenerated IVDs. The high cell proliferation observed in vitro in the hyaluronan could have been a negative factor in vivo, since most cell/gel transplanted IVDs showed degenerative changes at MRI and positive bone mineralization staining. However, this xenotransplantation model is valuable for evaluating possible cell therapy strategies for human degenerated IVDs.
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden.|Department of Orthopaedics, Sahlgrenska University, Gothenburg University, Gothenburg, Sweden.
authors.forename: H B
authors.initials: HB
authors.lastname: Henriksson
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Hagman
authors.affiliation: Department of Radiophysics, the Sahlgrenska Academy, Gothenburg University and Institute of Radiology, University of Würzburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Horn
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Lindahl
authors.affiliation: Department of Orthopaedics, Sahlgrenska University, Gothenburg University, Gothenburg, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Brisby
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic; D060846:Cell Engineering / Q000379:methods; D064987:Cell- and Tissue-Based Therapy / Q000379:methods*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000637:transplantation; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism; D005782:Gels; D064593:Heterografts; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007403:Intervertebral Disc / Q000166:cytology; D055959:Intervertebral Disc Degeneration / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods; D013552:Swine; D013556:Swine, Miniature
chemical_list: D005782:Gels