Prolonged cryopreservation of human bone marrow

Area of Science:

• Hematology
• Cryobiology
• Cellular Biology

Background:

• Effective cryopreservation of human bone marrow is crucial for hematopoietic stem cell transplantation.
• Long-term storage viability of bone marrow cells, particularly hematopoietic stem cells, needs rigorous assessment.

Purpose of the Study:

• To evaluate the viability of human bone marrow after prolonged storage in the vapor phase of liquid nitrogen.
• To assess the impact of cryopreservation and thawing on nucleated cell count and colony-forming cell (CFU-c) efficiency.

Main Methods:

• Human bone marrow from eight patients was cryopreserved for 40-42 months in 10% DMSO.
• Cell counts and CFU-c plating efficiency were measured before freezing, after thawing, and after DMSO removal and incubation.
• Discontinuous centrifugation was used to concentrate nucleated cells.

Main Results:

• Prolonged vapor phase storage resulted in a median cell loss of 9% and a 2% increase in CFU-c plating efficiency.
• DMSO dilution, washing, and incubation led to cell losses of 19-24% but increased CFU-c plating efficiency by 22-79%.
• Viable CFU-c counts remained comparable to pre-storage levels throughout the process.

Conclusions:

• Vapor phase liquid nitrogen storage is a suitable method for long-term human bone marrow cryopreservation.
• The method maintains adequate viability of hematopoietic stem cells, as indicated by CFU-c efficiency.
• This technique supports the potential for successful future clinical applications of cryopreserved bone marrow.