Point-of-care treatment of focal cartilage defects with selected chondrogenic mesenchymal stromal cells-An in vitro proof-of-concept study

Abstract

Due to the poor self-healing capacities of cartilage, innovative approaches are a major clinical need. The use of in vitro expanded mesenchymal stromal cells (MSCs) in a 2-stage approach is accompanied by cost-, time-, and personnel-intensive good manufacturing practice production. A 1-stage intraoperative procedure could overcome these drawbacks. The aim was to prove the feasibility of a point-of-care concept for the treatment of cartilage lesions using defined MSC subpopulations in a collagen hydrogel without prior MSC monolayer expansion. We tested 4 single marker candidates (MSCA-1, W4A5, CD146, CD271) for their effectiveness of separating colony-forming units of ovine MSCs via magnetic cell separation. The most promising surface marker with regard to the highest enrichment of colony-forming cells was subsequently used to isolate a MSC subpopulation for the direct generation of a cartilage graft composed of a collagen type I hydrogel without the propagation of MSCs in monolayer. We observed that separation with CD271 sustained the highest enrichment of colony-forming units. We then demonstrated the feasibility of generating a cartilage graft with an unsorted bone marrow mononuclear cell fraction and with a characterized CD271 positive MSC subpopulation without the need for a prior cell expansion. A reduced volume of 6.25% of the CD271 positive MSCs was needed to achieve the same results regarding chondrogenesis compared with the unseparated bone marrow mononuclear cell fraction, drastically reducing the number of nonrelevant cells. This study provides a proof-of-concept and reflects the potential of an intraoperative procedure for direct seeding of cartilage grafts with selected CD271 positive cells from bone marrow.

Characterisation of ovine bone marrow-derived stromal cells (oBMSC) and evaluation of chondrogenically induced micro-pellets for cartilage tissue repair in vivo

“…CD146 is viewed as one of the defining markers of hBMSC and is associated with hBMSC capacity to form ectopic marrows and support haematopoietic stem cells [22,23]. CD271 has been reported to be expressed on the surface of hBMSC [24] and oBMSC [25]. However, CD271 + cell number in hBMSC cultures declines rapidly in response to medium serum supplementation [26], and our hBMSC control population and Fig.…”

Size-Based Microfluidic-Enriched Mesenchymal Stem Cell Subpopulations Enhance Articular Cartilage Repair

“…Although MSCs with improved cartilage repair potential could be isolated with a fluorescence-activated cell sorting approach using specific surface proteins such as CD271 35,36 and CD146, 11,44 these surface markers decrease during MSC expansion. In fact, a comparison of MSC sizes and the expression of these 2 surface markers found insignificant differences across the size-sorted subpopulations.…”

Two-Year Follow-Up and Remodeling Kinetics of ChonDux Hydrogel for Full-Thickness Cartilage Defect Repair in the Knee

“…An appropriate biomaterial may mitigate this variability by providing a more natural mechanical and structural environment. 24 Several biomaterials have been investigated in preclinical and clinical studies that use microfracture as a cell source. Solid, preformed scaffolds composed of porous polyglycolic acid/hyaluronic acid 25 can be trimmed to the defect size and implanted.…”