The suppression of Type X Collagen Expression is Maintained when Mesenchymal Stem Cells from Osteoarthritis Patients are Pre-Cultured on Nitrogen Rich Polymers and then Transferred to Pellet Cultures

Rampersad, S; Petit, A; Ruiz, JC; Wertheimer, MR; Antoniou, J; Mwale, F. Division of Orthopaedic Surgery, McGill University, Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC, Canada Department of Engineering Physics, ÉcolePolytechnique, Montréal, Québec, Canada email: [email protected] INTRODUCTION Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into chondrocytes, osteoblasts, myocytes, adipocytes, and a variety of other connective tissues. Using MSCs from osteoarthritic (OA) patients for cartilage repair has been proposed in several studies because these patients will require a source of autologous stem cells if biological repair of cartilage lesions is to be a therapeutic option. Previous studies had shown that a major drawback of current cartilage and intervertebral disc tissue engineering and repair is that human MSCs from OA patients express high levels of type X collagen [1]. Type X collagen, a marker of late stage chondrocyte hypertrophy [2], is linked with endochondral ossification, which is a prelude to bone formation. However, these studies also revealed that a novel atmospheric-pressure plasma-polymerized thin film material, called nitrogen-rich plasmapolymerized ethylene (PPE:N), is able to inhibit type X collagen expression in committed MSCs [3]. The specific aim of this study was to determine if the suppression of type X collagen by PPE:N is maintained when MSCs are transferred to pellet cultures in serum-free chondrogenic defined media.