Mesenchymal stem cells (MSCs) culture fluids are frozen and thawed for long-term storage when needed for medical purposes. However, stresses accompanied with freezing and thawing can disrupt the tertiary structures of proteins, which need to be in a certain state to show their therapeutic effect, by affecting their internal interactions. Supercritical drying of MSCs culture fluids using carbon dioxide was conducted to resolve these problems. Various process parameters were controlled to improve process efficiency in the water displacement step which takes place prior to supercritical drying. Among the proteins contained in the MSCs culture fluids, vascular endothelial growth factor (VEGF) was selected as a representative material to optimize the process parameters. Analyzed results show that the tertiary structures of VEGF via supercritical drying are well preserved. In addition, the structural stability and bioactivity of VEGF when re-dissolved in an aqueous environment were better than those obtained from freeze drying.

将间充质干细胞（MSCs）培养液冷冻并解冻，以便在医疗上需要时长期保存。但是，伴随冷冻和解冻的压力可能会破坏蛋白质的三级结构，而三级结构必须处于某种状态才能通过影响其内部相互作用来发挥其治疗作用。为了解决这些问题，进行了使用二氧化碳超临界干燥MSCs培养液的研究。在超临界干燥之前进行的水置换步骤中，控制了各种工艺参数以提高工艺效率。在MSCs培养液中包含的蛋白质中，选择血管内皮生长因子（VEGF）作为代表性材料以优化工艺参数。分析结果表明，通过超临界干燥的VEGF的三级结构得到了很好的保存。另外，当重新溶于水性环境中时，VEGF的结构稳定性和生物活性优于冷冻干燥获得的那些。