Isolation of clinically relevant concentrations of bone marrow mesenchymal stem cells without centrifugation

Abstract

Background: This study examined the quality of bone marrow aspirates extracted using a novel, FDA cleared method to optimally target cells from the inner cortical iliac bone surface without the need for centrifugation. This method employs small draws from a single puncture that promote only lateral flow from multiple sites (SSLM method). The study utilized the Marrow Cellutions bone marrow aspiration system (MC system) which is based on the SSLM method and compared the MC system directly to bone marrow concentrates (BMAC) generated by centrifugation of aspirates harvested with a standard aspiration needle.

Methods: Three direct comparisons were conducted evaluating the SSLM draws and BMACs derived from the same patient from contralateral iliac crests. The levels of TNCs/mL, CD34+ cells/mL, CD117+ cells/mL, and CFU-f/mL were compared between the various bone marrow preparations. The cellular content of a series of SSLM draws was also analyzed to determine the total nucleated cell (TNC) count and the concentration of mesenchymal stem/progenitor cells as measured by colony forming unit fibroblasts (CFU-f).

Results: In direct comparisons with BMAC systems, SSLM draws yielded significantly higher CFU-f concentrations and comparable concentrations of CD34+ and CD117+ cells. In addition, the average quantity of TNCs/mL in a series of 30 patients utilizing the SSLM draw was 35.2 × 10⁶ ± 17.1 × 10⁶ and the average number of CFU-f/mL was 2885 ± 1716. There were small but significant correlations between the TNCs/mL and the CFU-fs/mL using the SSLM method as well as between the age of the patient and the CFU-fs/mL.

Conclusions: The MC Device, using the SSLM draw technique, produced concentrations of CFU-fs, CD34+ cells and CD117+ cells that were comparable or greater to BMACs derived from the same patient. Given the rapid speed and simplicity of the MC Device, we believe this novel system possesses significant practical advantages to other currently available centrifugation based systems.

Keywords: Bone marrow aspirate; Hematopoietic stem cells; Mesenchymal stem cells.

Fig. 1

Number of CFU-fs and TNCs in bone marrow aspirates obtained using the MC system (SSLM method). a The average number of TNCs/mL was 33.3 × 10⁶ ± 13.9 × 10⁶ when removing the outlier case (90.0 million TNCs/mL). When all cases are included, the average count was 35.2 × 10⁶ ± 17.1 × 10⁶ (n = 30). b The average number of CFU-fs/mL was 2885 ± 1716 (n = 30)

Fig. 2

a Correlation between CFU-fs/mL and total nucleated cells/mL in bone marrow aspirates harvested using the SSLM method. Because the data were not normally distributed, the Spearman’s rank-order correlation test was used. The Spearman coefficient was 0.4848, indicating a positive correlation between the two variables that was significant (p = 0.0062). b Correlation between CFU-fs/mL and age in bone marrow aspirates harvested using the SSLM method. Because the data were normally distributed, the Pearson’s correlation test was used. The Pearson correlation coefficient was − 0.4689, indicating a negative correlation between the two variables that was significant (p = 0.009)