RESUMO
The present study was aimed to investigate the influence of freeze-drying on the quality of polymerized human placenta hemoglobin (PolyPHb). The PolyPHb solution was freeze-drying under suitable conditions. Hemoglobin concentration, methemoglobin (MetHb) content, UV spectrum, Fe3 content, oxygen-carrying capacity, pH, the average molecular weight and its distribution, circular dichroism, oxygen equilibrium curve and other indicators were measured before and after freeze-drying. The appearance, residual water content, rehydration time of the lyophilized product were also evaluated. The results showed that there was no significant difference on all the indicators measured above, which indicated that freeze-drying process had no effect on the physical and chemical properties of PolyPHb, as well as on its biological activity. Therefore, the properties of PolyPHb were stable during this freeze-drying process and could be preserved after such freeze-drying process.