TY - JOUR A1 - Schwab, Andrea A1 - Buss, Alexa A1 - Pullig, Oliver A1 - Ehlicke, Franziska T1 - Ex vivo osteochondral test system with control over cartilage defect depth – A pilot study to investigate the effect of oxygen tension and chondrocyte based treatments in chondral and full thickness defects in an organ model JF - Osteoarthritis and Cartilage Open N2 - Objective Cartilage defect treatment strategies are dependent on the lesion size and severity. Osteochondral explant models are a platform to test cartilage repair strategies ex vivo. Current models lack in mimicking the variety of clinically relevant defect scenarios. In this controlled laboratory study, an automated device (artificial tissue cutter, ARTcut®) was implemented to reproducibly create cartilage defects with controlled depth. In a pilot study, the effect of cartilage defect depth and oxygen tension on cartilage repair was investigated. Design Osteochondral explants were isolated from porcine condyles. 4 ​mm chondral and full thickness defects were treated with either porcine chondrocytes (CHON) or co-culture of 20% CHON and 80% MSCs (MIX) embedded in collagen hydrogel. Explants were cultured with tissue specific media (without TGF-β) under normoxia (20% O\(_2\)) and physiological hypoxia (2% O\(_2\)). After 28 days, immune-histological stainings (collagen II and X, aggrecan) were scored (modified Bern score, 3 independent scorer) to quantitatively compare treatment outcome. Results ARTcut® represents a software-controlled device for creation of uniform cartilage defects. Comparing the scoring results of the MIX and the CHON treatment, a positive relation between oxygen tension and defect depth was observed. Low oxygen tension stimulated cartilaginous matrix deposition in MIX group in chondral defects and CHON treatment in full thickness defects. Conclusion ARTcut® has proved a powerful tool to create cartilage defects and thus opens a wide range of novel applications of the osteochondral model, including the relation between oxygen tension and defect depth on cartilage repair. KW - cartilage defectex vivo model KW - cartilage test system KW - chondrocytes KW - MSC KW - collagen type I hydrogel Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260511 VL - 3 IS - 2 ER - TY - JOUR A1 - Schmidt, Stefanie A1 - Abinzano, Florencia A1 - Mensinga, Anneloes A1 - Teßmar, Jörg A1 - Groll, Jürgen A1 - Malda, Jos A1 - Levato, Riccardo A1 - Blunk, Torsten T1 - Differential production of cartilage ECM in 3D agarose constructs by equine articular cartilage progenitor cells and mesenchymal stromal cells JF - International Journal of Molecular Sciences N2 - Identification of articular cartilage progenitor cells (ACPCs) has opened up new opportunities for cartilage repair. These cells may be used as alternatives for or in combination with mesenchymal stromal cells (MSCs) in cartilage engineering. However, their potential needs to be further investigated, since only a few studies have compared ACPCs and MSCs when cultured in hydrogels. Therefore, in this study, we compared chondrogenic differentiation of equine ACPCs and MSCs in agarose constructs as monocultures and as zonally layered co-cultures under both normoxic and hypoxic conditions. ACPCs and MSCs exhibited distinctly differential production of the cartilaginous extracellular matrix (ECM). For ACPC constructs, markedly higher glycosaminoglycan (GAG) contents were determined by histological and quantitative biochemical evaluation, both in normoxia and hypoxia. Differential GAG production was also reflected in layered co-culture constructs. For both cell types, similar staining for type II collagen was detected. However, distinctly weaker staining for undesired type I collagen was observed in the ACPC constructs. For ACPCs, only very low alkaline phosphatase (ALP) activity, a marker of terminal differentiation, was determined, in stark contrast to what was found for MSCs. This study underscores the potential of ACPCs as a promising cell source for cartilage engineering. KW - ACPC KW - chondroprogenitors KW - tissue engineering KW - MSC KW - agarose KW - hypoxia KW - ECM KW - co-culture KW - zonal KW - cartilage Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236180 SN - 1422-0067 VL - 21 IS - 19 ER - TY - JOUR A1 - Herrmann, Marietta A1 - Hildebrand, Maria A1 - Menzel, Ursula A1 - Fahy, Niamh A1 - Alini, Mauro A1 - Lang, Siegmund A1 - Benneker, Lorin A1 - Verrier, Sophie A1 - Stoddart, Martin J. A1 - Bara, Jennifer J. T1 - Phenotypic characterization of bone marrow mononuclear cells and derived stromal cell populations from human iliac crest, vertebral body and femoral head JF - International Journal of Molecular Sciences N2 - (1) In vitro, bone marrow-derived stromal cells (BMSCs) demonstrate inter-donor phenotypic variability, which presents challenges for the development of regenerative therapies. Here, we investigated whether the frequency of putative BMSC sub-populations within the freshly isolated mononuclear cell fraction of bone marrow is phenotypically predictive for the in vitro derived stromal cell culture. (2) Vertebral body, iliac crest, and femoral head bone marrow were acquired from 33 patients (10 female and 23 male, age range 14–91). BMSC sub-populations were identified within freshly isolated mononuclear cell fractions based on cell-surface marker profiles. Stromal cells were expanded in monolayer on tissue culture plastic. Phenotypic assessment of in vitro derived cell cultures was performed by examining growth kinetics, chondrogenic, osteogenic, and adipogenic differentiation. (3) Gender, donor age, and anatomical site were neither predictive for the total yield nor the population doubling time of in vitro derived BMSC cultures. The abundance of freshly isolated progenitor sub-populations (CD45−CD34−CD73+, CD45−CD34−CD146+, NG2+CD146+) was not phenotypically predictive of derived stromal cell cultures in terms of growth kinetics nor plasticity. BMSCs derived from iliac crest and vertebral body bone marrow were more responsive to chondrogenic induction, forming superior cartilaginous tissue in vitro, compared to those isolated from femoral head. (4) The identification of discrete progenitor populations in bone marrow by current cell-surface marker profiling is not predictive for subsequently derived in vitro BMSC cultures. Overall, the iliac crest and the vertebral body offer a more reliable tissue source of stromal progenitor cells for cartilage repair strategies compared to femoral head. KW - bone marrow stromal cells KW - MSC KW - pericytes KW - femoral head KW - vertebral body KW - iliac crest KW - chondrogenesis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285054 SN - 1422-0067 VL - 20 IS - 14 ER - TY - JOUR A1 - Herrmann, Marietta A1 - Diederichs, Solvig A1 - Melnik, Svitlana A1 - Riegger, Jana A1 - Trivanović, Drenka A1 - Li, Shushan A1 - Jenei-Lanzl, Zsuzsa A1 - Brenner, Rolf E. A1 - Huber-Lang, Markus A1 - Zaucke, Frank A1 - Schildberg, Frank A. A1 - Grässel, Susanne T1 - Extracellular Vesicles in Musculoskeletal Pathologies and Regeneration JF - Frontiers in Bioengineering and Biotechnology N2 - The incidence of musculoskeletal diseases is steadily increasing with aging of the population. In the past years, extracellular vesicles (EVs) have gained attention in musculoskeletal research. EVs have been associated with various musculoskeletal pathologies as well as suggested as treatment option. EVs play a pivotal role in communication between cells and their environment. Thereby, the EV cargo is highly dependent on their cellular origin. In this review, we summarize putative mechanisms by which EVs can contribute to musculoskeletal tissue homeostasis, regeneration and disease, in particular matrix remodeling and mineralization, pro-angiogenic effects and immunomodulatory activities. Mesenchymal stromal cells (MSCs) present the most frequently used cell source for EV generation for musculoskeletal applications, and herein we discuss how the MSC phenotype can influence the cargo and thus the regenerative potential of EVs. Induced pluripotent stem cell-derived mesenchymal progenitor cells (iMPs) may overcome current limitations of MSCs, and iMP-derived EVs are discussed as an alternative strategy. In the last part of the article, we focus on therapeutic applications of EVs and discuss both practical considerations for EV production and the current state of EV-based therapies. KW - extracellular vesicles KW - exosomes KW - musculoskeletal diseases KW - MSC KW - iMP KW - cell-free therapeutics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222882 SN - 2296-4185 VL - 8 ER - TY - JOUR A1 - Bothe, Friederike A1 - Deubel, Anne-Kathrin A1 - Hesse, Eliane A1 - Lotz, Benedict A1 - Groll, Jürgen A1 - Werner, Carsten A1 - Richter, Wiltrud A1 - Hagmann, Sebastien T1 - Treatment of focal cartilage defects in minipigs with zonal chondrocyte/mesenchymal progenitor cell constructs JF - International Journal of Molecular Sciences N2 - Despite advances in cartilage repair strategies, treatment of focal chondral lesions remains an important challenge to prevent osteoarthritis. Articular cartilage is organized into several layers and lack of zonal organization of current grafts is held responsible for insufficient biomechanical and biochemical quality of repair-tissue. The aim was to develop a zonal approach for cartilage regeneration to determine whether the outcome can be improved compared to a non-zonal strategy. Hydrogel-filled polycaprolactone (PCL)-constructs with a chondrocyte-seeded upper-layer deemed to induce hyaline cartilage and a mesenchymal stromal cell (MSC)-containing bottom-layer deemed to induce calcified cartilage were compared to chondrocyte-based non-zonal grafts in a minipig model. Grafts showed comparable hardness at implantation and did not cause visible signs of inflammation. After 6 months, X-ray microtomography (µCT)-analysis revealed significant bone-loss in both treatment groups compared to empty controls. PCL-enforcement and some hydrogel-remnants were retained in all defects, but most implants were pressed into the subchondral bone. Despite important heterogeneities, both treatments reached a significantly lower modified O’Driscoll-score compared to empty controls. Thus, PCL may have induced bone-erosion during joint loading and misplacement of grafts in vivo precluding adequate permanent orientation of zones compared to surrounding native cartilage. KW - cartilage repair KW - osteochondral defect KW - tissue engineering KW - starPEG hydrogel KW - chondrocyte KW - MSC KW - zonal construct KW - minipig Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285118 SN - 1422-0067 VL - 20 IS - 3 ER -