Survival rate of cryopreserved rat fat granuales after autologous transplantation

Objective To observe the fat particles survival situations in autologous transplantation under different conditions of low temperature. Methods Three sample groups of adult Wistar rats were injected with fresh autologous fat particles, which were stored under 80 ℃ for two months and under 196 ℃ for two months respectively, and the volume, parallel histological detection, glucose transport measurement, MTT experiments and other data were compared and analyzed one month and two months after the transplantation. Results One month after transplantation, graft survival rate was higher in Group injected fresh autologous fat particles than that of Group injected autologous fat particles stored under 80 ℃ and Group injected autologous fat particles stored under 196 ℃ (P<0.05); Two months after transplantation, the differences among three groups had no statistical significance. Before the transplantation, the activity of autologous fat particles stored in 80 ℃ and 196 ℃ were 68.7% and 62.5% of fresh autologous fat particles, respectively, two months after cryopreservation. One month after the transplantation, we found that the activities of autologous fat particles were higher in fresh group than that of 196 ℃ and 80 ℃, There was no significant difference between the groups stored in 196 ℃ and 80 ℃. Two months after the transplantation, the activities of autologous fat particles were higher in fresh group than that of 196 ℃ and 80 ℃. Before transplantation, the particles of fat histology showed no significant difference among three groups. One month after transplantation, fat vacuoles and distinct inflammatory infiltration were observed in all three groups, with the group stored in 80 ℃ as the most serious affected. Two months after transplantation, fresh fat particles and Group stored in 196 ℃ showed large quantity of tightly packed intact fat cells, scattered around the central area in fat vacuoles, while Group stored in 80 ℃ still had a large quantity of fat vacuoles, but the fat vacuoles were obviously fused. Conclusions The fat stored at80 ℃ and196 ℃ could meet the needs of clinical use in the short time. The fat stored at 196 ℃ shows the best activity. The fat particles stored at196 ℃ could be used to establish better blood circulation. The heaviest inflammatory reaction occurs in the graft zone one month after fat transplantation and the decrease of transplanted particle activity is the most obvious. Key words: Rats; Cryopreservation; Cryoprotective agents; Fat granule; Cell activity