Human Synovial Mesenchymal Stem Cells Good Manufacturing Practices for Articular Cartilage Regeneration

Abstract

Background: Cartilage restoration is a desperately needed bridge for patients with symptomatic cartilage lesions. Chondral lesion is a pathology with high prevalence, reaching as much as 63% of general population and 36% among athletes. Despite autologous chondrocyte implantation versatility, it still fails to fully reproduce hyaline articular cartilage characteristics. Mesenchymal stem cells (MSCs) may be isolated from various known tissues, including discarded fragments at arthroscopy such as synovial membrane. Choice of harvesting site is motivated by MSCs' abilities to modulate immunologic and inflammatory response through paracrine communication. Synovial MSCs have a greater proliferation and strong chondrogenic potential than bone and adipose MSCs and a less hypertrophic differentiation than bone MSCs. Good manufacturing practice (GMP) laboratory techniques for human clinical trials are still novel. To our knowledge, there are only two clinical trials in humans published since today.Purpose: Therefore, this work aimed to isolate and characterize synovial MSCs and evaluated their differentiation properties according to GMP standards.Materials and Methods: One-gram tissue sample from three patients of synovia was harvested at the beginning of arthroscopy surgery. MSCs were isolated, expanded, and characterized by flow cytometry.Results: It was possible to isolate and expand MSCs cultures from synovia, characterize MSCs by flow cytometry using proper monoclonal antibodies, and differentiate MSCs by coloring technique after chondrogenic, adipogenic, and osteogenic differentiations. Cartilage treatment may benefit from these tissue engineering protocols since arthroscopic procedures are routinely performed for different purposes in a previous stage and a favorable chondronegic differentiation cell lineage may be collected and stored in a less invasive way.Conclusion: Laboratory protocols established according to presented GMP were able to isolate and characterize MSCs obtained from synovia.Impact StatementArticular cartilage restoration is a desperately needed bridge for patients with symptomatic cartilage lesions and it rises as a socioeconomic issue with a considerable economic burden. Synovial mesenchymal stem cells (MSCs) have a greater proliferation rate and strong chondrogenic potential than bone and adipose MSCs and a less hypertrophic differentiation than bone MSCs. To our knowledge, there are only two human clinical trials with good manufacturing practice laboratory techniques for synovial MSCs harvesting and differentiation. Cartilage treatment may benefit from these tissue engineering protocols since arthroscopic procedures are routinely performed for different purposes in a previous stage.

Evaluation of the Effects of Synovial Multipotent Cells on Deep Digital Flexor Tendon Repair in a Large Animal Model of Intra‐Synovial Tendinopathy

“…A comparable yield of cells from synovium have been isolated from pathological knee and hip joints exhibiting a “mixed” cell‐surface marker profile similar to this study . Furthermore, a similar cell‐surface marker expression profile for synovium‐derived trilineage positive cells has been reported in this study, though the authors have interpreted CD166 as a possible discriminating factor between multipotent and fibroblastic cells . In contrast, assessing the ameliorative effects of synovial MSCs in an osteoarthritic mouse model, synovial MSCs were reported to be highly positive for CD73, CD90, and CD105 .…”

“…While the hematopoietic marker CD34 was absent, there was variable expression of CD45 and MHC‐II, indicating potential inclusion of leukocytic cells from perivascular tissue. However, these profiles are not dissimilar to recent studies of synovial MSCs derived from inflammed human knee joints . Hagmann et al reported differences between donor‐typed bone marrow and synovial MSCs with the latter uniformly exhibiting trilineage differentiation and strongly positive for CD73, CD90, CD105, and MHC‐I although small levels of CD34 and CD45 positive cells were also detected.…”

“…22 Furthermore, a similar cell-surface marker expression profile for synovium-derived trilineage positive cells has been reported in this study, though the authors have JOURNAL OF ORTHOPAEDIC RESEARCH ® JANUARY 2020 interpreted CD166 as a possible discriminating factor between multipotent and fibroblastic cells. 26 In contrast, assessing the ameliorative effects of synovial MSCs in an osteoarthritic mouse model, synovial MSCs were reported to be highly positive for CD73, CD90, and CD105. 27 The lack of CD105 and CD271 with moderate CD73 positive cells was reported for the surface and stromal synovia from human arthritic joints.…”

“…However, these profiles are not dissimilar to recent studies of synovial MSCs derived from inflammed human knee joints. 18,[21][22][23][25][26][27] Hagmann et al 25 reported differences between donor-typed bone marrow and synovial MSCs with the latter uniformly exhibiting trilineage differentiation and strongly positive for CD73, CD90, CD105, and MHC-I although small levels of CD34 and CD45 positive cells were also detected. A comparable yield of cells from synovium have been isolated from pathological knee and hip joints exhibiting a "mixed" cell-surface marker profile similar to this study.…”

Macrophage: A Potential Target on Cartilage Regeneration

“…ACI is a two-step procedure that consists of healthy cartilage harvesting through arthroscopy followed by the expanded cell culture and, in a second step, cartilage defect filling (13)(14)(15). In spite of second and third ACI generations' versatility, those techniques use healthy cartilage tissue, "in vitro" related chondrocytes dedifferentiation and still fails to fully reproduce the hyaline characteristics of the original articular cartilage (6,13,(15)(16)(17).…”