This study was purposed to evaluate the effect of different lyophilizing protectants including
human albumin,
glucan,
polyvinyl pyrrolidone and
glycerine on lyophilized
trehalose-loading red blood cells (RBC), then to screen the optimal lyophilizing protectant. The RBC were incubated in 800 mmol/L concentration of
trehalose solution at 37°C for 7 hours, and washed 3 times with PBS
solution to obtain the
trehalose-loading RBC. The
trehalose-loading RBC in control group were directly lyophilized without lyophilizing protectants, the
trehalose-loading RBC in the experimental group were mixed with Lyophilizing protectants. The samples of 2 groups were kept at room temperature for 30 minutes, pre-frozen at -80°C for 24 hours, then lyophilized in freeze-dryer for 24 hours. Finally the samples were quickly rehydrated by 6% HES at 37°C. The recovery rate and
hemolysis rate of
hemoglobin were detected by using
cyanohemoglobin detection kit. The water content of unhydrated samples were detected at the same time. The results showed that when the moisture content of sample was 3% - 5%, the recovery rate of
hemoglobin in control group was 33.57 ± 2.89%, and that in experimental group was 51.15 ± 1.98%, there was statistically significant difference between the control and experimental group (P < 0.05). When the different concentration of
dextran solution was chosen as protectants, the recovery rate of
hemoglobin of lyophilized RBC was obviously lower. The higher concentration of
dextran, the better the recovery rate. The recovery rate of
hemoglobin was 22.15 ± 4.12% when the concentration of
dextran was 36%, there were statistically significant difference between the two groups (P < 0.05). When the different concentration of
polyvinyl pyrrolidone (PVP) solutions was chosen as protectants, especially the concentration below 40%, the recovery rate of
hemoglobin of lyophilized RBC was significantly belower than the control group, there was statistically significant difference between the two groups (P < 0.05). When 10%
glycerol was used as protectants, the recovery rate of
hemoglobin was 3.93 ± 1.80%. There was also statistically significant difference between the two groups (P < 0.05). It is concluded that
human serum albumin shows an important protective effect on the lyophilization of the
trehalose-loading red blood cells. The
dextran and PVP at the concentration lower than 40% can decrease the protective effect of
trehalose in cells.
Glycerol can not be chosen as protectant for lyophilized
trehalose-loading red blood cells.