Abstract
Background: Long-term preservation of adipose tissue is crucial for clinical applications. Researchers should consider both efficiency and biosafety when choosing a cryoprotective agent (CPA) for adipose tissue preservation. Glycerol has been applied as a nontoxic CPA for multiple tissues but not adipose tissue. We aimed to evaluate the efficacy of glycerol as a CPA for adipose tissue cryopreservation.Methods: Fresh human adipose tissues were obtained from ten patients who underwent liposuction and divided into 1 ml samples. Each sample was randomly mixed with 1 ml of CPA: 60 to 100% glycerol, 0.25 mol/L trehalose or DMSO+FBS and cryopreserved in -196 °C liquid nitrogen for one month. After thawing and elution, the tissues were immediately evaluated for activity and structural integrity in vitro. Then, 0.2 ml of each sample was transplanted subdermally to the nude mouse dorsum and harvested after one month for histological examination to assess the effect of the cryopreserved fat in transplantation.Results: After cryopreservation, the samples treated with DMSO+FBS, trehalose, and 60% and 70% glycerol had a more integrated structure than the samples in other groups. Tissues preserved with 70% glycerol had the highest tissue activity, close to that of fresh tissues. Adipose-derived stem cells (ADSC) viability, proliferation and differentiation capability were also better in 70% glycerol group. In vivo analysis showed that tissue preserved with 70% glycerol had superior retention rates and structural integrity. Compared to the DMSO+FBS and trehalose groups, the glycerol group showed lower inflammation.Conclusion: Glycerol (70%) is efficient in adipose tissue cryopreservation. Glycerol-based CPAs, which are nontoxic and show biosafety, are a promising solution for clinical tissue cryopreservation.
Adipose tissue derived stem cells: in vitro and in vivo analysis of a standard and three commercially available cell-assisted lipotransfer techniques