Evaluation of Concentrated Bone Marrow-derived Mesenchymal Stem Cells Produced from Two Different Cellular Concentrating Systems.

Background. Concentrated bone marrow-derived mesenchymal stem cells (concentrated bMSCs) are used to improve in-vivo healing, yet in-vivo studies do not describe the cellular components that constitute the concentrated bMSCs. If different concentrating systems create concentrated bMSCs with different cellular components this could affect in-vivo study results. This study sought to compare the cellular components of concentrated bMSCs from two different separating systems. Methods. Matched bone marrow (BM) and whole blood were commercially obtained. BM was divided, processed then the concentrated bMSCs were plated and analyzed for cellular concentrates, morphology, triplex, and proliferation assays. The two separation systems used were Angel (system 1) produced from Arthrex, Inc, Naples FL and Smart- Prep (system 2) produced from Harvest Technologies, Lakewood, CO. Time points used were 1, 4, 24, 48, 72 and 96 hours. Blinded observers were used to assess morphology of cells at the 24 hour time point. Results. System 1 had significantly more CFUs (p=.0035) and more nucleated cells (p=.0056). Proliferation was significantly increased for system 1 at time points 1, 24, 48, 72, and 96 hours (p<.001). Cellular viability was significantly increased for system 1 at time points 1, 24 and 48 hours (p<.05). Apoptosis was significantly increased for system 1 at time points 1, 4, 24, 48, 72, 96 hours (p<.05). Cytotoxicity was significantly increased for system 1 at time points 1, 4, 24, 48, 72, 96 hours (p<.001). Morphology of System 1's cells were more consistent of mesenchymal stem cells (MSCs) (Kappa=0.44). Conclusion. Systems that are used to create concentrated bMSCs create populations of concentrated bMSCs with different cellular properties. Future in-vivo studies involving this cell population should describe the cellular properties of the concentrated bMSCs. [ABSTRACT FROM AUTHOR]