Effects of equine bone marrow aspirate volume on isolation, proliferation, and differentiation potential of mesenchymal stem cells.

This research investigates the effects of using different volumes of horse bone marrow aspirate on the isolation, proliferation, and differentiation of mesenchymal stem cells. The findings suggest that there is no additional advantage in using 50-ml aspirates over 5-ml aspirates for the culture-expansion of these stem cells for use in equine clinical applications.

Study Design and Procedure

• The researchers studied six horses aged between two to five years old. The horse breeds were mixed.
• Different amounts of bone marrow aspirates were drawn from each horse. The amounts were either 5 ml or 50 ml. The locations of the extractions were either the ilium (part of the hip bone) or the sternebra (a segment of the breastbone).
• MSC yield was quantified through the process of culture expansion, which involves growing cells in a controlled environment.
• Conventional laboratory methods were employed to evaluate the potential of the stem cells to transform into chondrogenic (cartilage) and osteogenic (bone) cells.

Results of the Study

• The second of the two sequential 50-mL sternal aspirates yielded few or no MSCs, indicating that larger volume doesn’t necessarily result in a higher yield of cells.
• The highest density of MSCs was found in the first of the two sequential 5-mL fractions, irrespective of the extraction location. However, the overall yield after culture expansion was not significantly different between the first 5-mL and first 50-mL fractions, indicating that smaller volume of aspirate can yield a similar amount of MSCs as a larger volume.
• Chondrogenesis and osteogenesis were not significantly different among fractions, regardless of the extraction location. This suggests that the cell differentiation potential is not affected by the volume of the aspirate.
• The total cell yield and chondrogenesis from the ilium were significantly higher than that from the sternum, implying that the extraction location may affect the MSC yield and chondrogenesis potential.

Conclusions

• The study did not find any additional benefits of using 50-mL aspirates over 5-mL aspirates for the culture-expansion of MSCs for equine clinical applications.
• Chondrogenesis was highest for MSCs from ilial aspirates, but it is still unclear whether chondrogenesis is indicative of activation of other proposed pathways by which MSCs help in tissue repair.