Development of human-derived hemoglobin–albumin microspheres as oxygen carriers using Shirasu porous glass membrane emulsification

Novel hemoglobin-based artificial oxygen carriers are necessary in tissue engineering. We developed human hemoglobin (hHb) and albumin (HSA)-based microspheres using Shirasu porous glass (SPG) membrane emulsification. The obtained microspheres had a uniform size with an average diameter of 15.1 μm measured by optical microscope, which is similar to the diameter of human red blood cells (7–8 μm). The loading amount of hHb in the microspheres was 20 wt%, which is similar to that of red blood cells (33 wt%). The hHb–HSA microspheres showed similar oxygen dissociation behavior and methemoglobin formation resistance to native hHb. Incubation with genetically engineered HeLa cells that shows hypoxia-responsive EGFP expression demonstrated efficient oxygen supply from the microspheres. Our study suggests the utility of hHb–HSA microspheres as oxygen carriers for tissue engineering with a low risk of infectious disease.