Human blood cells at microgravity: the NASA Initial Blood Storage Experiment

Area of Science:

• Biomedical research
• Space biology
• Hematology

Background:

• Understanding the effects of microgravity on biological samples is crucial for long-duration space missions.
• Previous research has indicated potential cellular changes in space, but comprehensive studies on blood components are limited.

Purpose of the Study:

• To investigate the behavior and integrity of human red blood cells, white blood cells (granulocytes), and platelets under microgravity conditions.
• To compare the effects of microgravity versus Earth gravity on blood cell function, morphology, metabolism, and immunology.

Main Methods:

• The Initial Blood Storage Experiment (IBSE) utilized identical blood cell sets, one exposed to microgravity on the STS 61-C mission and the other on Earth.
• Specially designed environmental chambers maintained controlled temperatures and airflow. A novel thin-layer compression method was used for platelet preservation.
• Blind assignment and coded sample identification ensured unbiased data collection and analysis using analysis of variance.

Main Results:

• Platelets exhibited markedly superior structural and functional integrity in microgravity compared to Earth gravity.
• Granulocytes were preserved slightly better under Earth gravity conditions than in microgravity.
• Red blood cells showed minimal effects attributable to the gravitational variable.

Conclusions:

• Microgravity appears to enhance the preservation of platelet structural and functional integrity.
• Different blood cell types exhibit varying responses to microgravity, with platelets showing the most significant benefit.
• The choice of storage material is critical, with PVC-TOTM demonstrating superiority for platelet storage over PVC-DEHP and PO.