Table 3.
Cryopreservation using trehalose vs. fresh fat control or simple cryopreservation.
| Ref. | Level of Evidence OCEBM | Methods, Slow Cooling and Rapid Rewarming | CPA Concentration mol/L, Groups | Temperature, °C | Time | Results |
|---|---|---|---|---|---|---|
| Cui et al. [6] 2009 | Level 3 | Adipose aspirates were cryopreserved using trehalose as a CPA in seven different concentrations and compared to a fresh fat control group for viability in vitro. A G3PDH assay was also performed to assess intracellular function. | Trehalose: (1) 0.20 mol/L; (2) 0.25 mol/L; (3) 0.30 mol/L; (4) 0.35 mol/L; (5) 0.40 mol/L; (6) 0.50 mol/L; (7) 0.75 mol/L; and (8) Control | −196 | 20 min | Cryopreservation with 0.35 mol/L trehalose was found to preserve the most adipocytes. This concentration of trehalose showed no statistical difference relative to control (2.4 ± 0.52 vs. 1.88 ± 0.61 × 106/mL; P > 0.05). No concentration of trehalose showed a significant difference in intracellular function relative to control (all P > 0.05). |
| Cui et al. [27] 2010 | Level 3 | 0.5 mL of cryopreserved fat grafts was thawed and injected into the posterior scalps of mice for 8 weeks. Weight, volume and histology of grafts were analysed at the end of the study. | (1) 0.5 mol/L DMSO + 0.2 mol/L trehalose; (2) 0.35 mol/L trehalose; and (3) Control (fresh fat graft) | −196 | 20 min | Group 2 and group 1 were inferior to the control group (both P < 0.05). There was a significantly higher percentage of maintained volume of injected fat in the control group (55.5% ± 11.7%) compared to group 1 (46.1% ± 14.4%, P < 0.05) or group 2 (38.2% ± 10.5%, P < 0.01). The control group showed a significantly higher maintained weight relative to both groups 1 (38.9% ± 14.7%, P < 0.01) and 2 (34.1% ± 12.1%, P < 0.01). |
| Rao et al. [15] 2015 | Level 3 | To determine the cryopreservation of primary hADSCs using nanoparticle-mediated intracellular delivery of trehalose as the sole CPA. | (1) 0.2 mol/L trehalose; (2) 100 mL/L DMSO; and (3) Fresh control | −196 | 1 day | hADSCs’ tissue architecture post cryopreservation with trehalose is similar to that of fresh isolates. Trehalose maintained comparable differentiation capabilities of the cryopreserved vs. fresh hADSCs. Trehalose acted as a successful cryoprotectant. |
| Pu et al. [31] 2005 | Level 3 | The efficacy of trehalose as the sole CPA for cryopreservation of adipocytes, with the aim to develop a protocol which enables optimal preservation of adipose tissues. | (1) Control fresh adipose aspirates; (2) Simple cryopreservation group: cryopreserved adipose aspirates without CPAs; and (3) Optimal cryopreservation group: 0.25 mol/L trehalose | −196 | 20 min | Adipocyte count was significantly higher in group 3 than group 2 (1.78 ± 0.33 vs. 0.99 ± 0.35 × 106/mL, P < 0.0001). Adipocyte count in group 3 was significantly lower than fresh isolates (1.78 ± 0.33 vs. 2.64 ± 0.54 × 106/mL, P < 0.001). The G3PDH activity in group 3 was also significantly lower than control (0.24 ± 0.07 vs. 0.32 ± 0.09 U/mL, P < 0.05). There was a statistically significant increase in G3PDH activity, which was significantly higher in group 3 relative to group 2 (0.24 ± 0.07 vs. 0.15 ± 0.06 U/mL, P < 0.01). |
| Cui et al. [23] 2007 | Level 3 | In vitro study where different cryoprotectant agents and their concentrations were tested. | (1) Fresh adipose aspirates; (2) Cryopreserved adipose aspirates without CPAs; and (3) Cryopreserved adipose aspirates with CPAs. (1) 0.2 mol/L DMSO + 0.1 mol/L trehalose; (2) 0.5 mol/L DMSO + 0.2 mol/L trehalose; (3) 0.25 mol/L trehalose; (4) 0.5 mol/L trehalose; (5) 1.0 mol/L DMSO; and (6) 1.5 mol/L DMSO | −196 | 20 min | The viable adipocyte count in the fresh fat control group was still significantly higher than the count in any of the six different CPA groups (all P < 0.0001). Significantly higher integrated viable adipocyte count of adipose aspirates was found in group 3 compared with group 2 (2.06 ± 0.54 × 106/mL vs. 1.07 ± 0.41 × 106/mL, P < 0.001). |
OCEBM: Oxford Centre for Evidence-Based Medicine; CPA: Cryoprotective agent; hADSCs: Human adipose-derived stem cells; DMSO: Dimethyl sulfoxide; G3PDH: Glycerol-3-phosphate dehydrogenase.