Submicron biodegradable polymer membrane hemoglobin nanocapsules as potential blood substitutes: a preliminary report

We used biodegradable polymers like polylactic acid, poly-isobutylcyanoacrylate and others to prepare nanocapsules containing hemoglobin. We prepared the optimal mean diameters of between 0.08 to 0.12 micron (80-120 nm). They are spherical and homogeneous. The membrane thickness is 0.005-0.015 micron (5-15nm). With different formulation, the hemoglobin contents in the particles may be varied from 30-45%. Phospholipid is not required in bovine hemoglobin. It is required for human hemoglobin in order to retain cofactors required for optimal P50. The P50 of the biodegradable polymer membrane containing bovine hemoglobin was between 27-29 mmHg. This is the same P50 as bovine hemoglobin used in the preparation. Thus the procedure of preparation did not damage hemoglobin.