Efficient procedure for human adipose tissue cryopreservation without specialized freezing equipment

BACKGROUND: Adipose tissue grafting is one of the reconstruction methods for damaged tissue repair. OBJECTIVE: To develop a convenient procedure for human adipose tissue cryopreservation without any special equipment. MATERIALS AND METHODS: Adipose tissues were frozen using different combinations of permeating and non-permeating cryoprotectants at a cooling rate of −1°C/min and stored at −20°C for 1, 3, 6 and 9 months. Histo‐morphological characteristics, mitochondrial activity, oil ratio (OR) index, survival and differentiation potential of mesenchymal stem cells of thawed adipose tissue were evaluated. RESULTS: The most damage or degeneration and OR indices of adipose tissues were detected in phosphate‐buffered saline without any cryoprotectant at 1, 3, 6, and 9 months after cryopreservation (P≤0.05). The best protection of adipose tissue against freezing damage was observed when using a solution of 0.5 M DMSO + 9% FBS + 0.2 M trehalose (P≤0.05). Similarly, mitochondrial activities of thawed adipose tissues were the highest in the 0.5 M DMSO + 9% FBS + 0.2 M trehalose, but lowest in the phosphate‐buffered saline. There was no difference in the stemness and differentiation potential of adipose tissue‐derived mesenchymal stem cells among different cryopreservation treatments. CONCLUSION: The combination of 0.5 M DMSO, 9% FBS and 0.2 M trehalose has the best protection for human adipose tissue during cryopreservation.