Freeze-drying Of Oxygen-carrying Substance And Storage Of The Freeze-dried Solids

Pyridoxalated placental polyhemoglobin solution (p. p-polypHb) can carry and unload oxygen, it has been widely tested in hemorrhage shock, organ preserving, enhancing the chemotherapy effect, improving microcirculation and so on. Yet, such solution is unstable; there are marked rise in MetHb content and visible change in molecular distribution upon storage.To facilitate storage, p. p-polypHb solution was put into freezedrying, and sucrose was chosen to control the MetHb formation. The contents of the paper fall into 3 parts: firstly, purified placental hemoglobin (pHb) was put into freeze-drying ; Secondly, based on the above experience, p. p-polypHb solution was put into freeze-drying; finally, freeze-dried solids (group B,C) were put under room and refrigerator for 3 months, characteristic of dried solids were determined then.The results are as following, when the mass ratio of sucrose: protein was above 0.5, there is no visible rise in MetHb content after freezedrying, other items of the dried solids such as the UV spectrum, SDS-PAGE, HPLC were nearly the same as that in native solution. Upon storage, the MetHb content did not increase for group B, C stored in refrigerator. Yet for those solids stored under room temperature, the MetHb content went up to 15% for group B, while that of group C was about 6%. There were no marked changes in items of dried solid after 3 months.