Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China.
Tissue Eng Part A. 2019 Dec;25(23-24):1614-1622. doi: 10.1089/ten.TEA.2019.0046. Epub 2019 Nov 20.
Large soft-tissue defects are challenging to reconstruct surgically. Expansion of soft tissue using an external volume expansion (EVE) device is a noninvasive method to improve such reconstruction; however, the underlying mechanism is unclear. In this study, we created fat flaps in Sprague-Dawley rats, applied an external force of 3 or 6 kPa using an EVE device, and investigated the migration and differentiation of adipose-derived stem/progenitor cells (ASCs). In addition, we performed finite element analysis to explore the stiffness of adipose tissue. An external force of 3 kPa promoted the migration and adipogenic differentiation of ASCs. By comparison, an external force of 6 kPa had a larger effect on migration of ASCs, but a smaller effect on adipogenic differentiation of ASCs. External force affected adipose tissue stiffness. In conclusion, external force generated by an EVE device increases the stiffness of adipose tissue, which influences the migration and differentiation of ASCs. The size of the external force can be altered according to the tissue stiffness required at particular time points to promote long-term adipose tissue regeneration. Impact Statement Stem cell therapy in clinic mostly requires the addition of exogenous stem cells, therefore the safety and controllability is always defective. In this study, the external force of external volume expansion regulates adipose-derived stem/progenitor cells (ASCs) migration and differentiation through tissue stiffness. Using tissue engineering without exogenous ASCs can promote long-term adipose tissue regeneration. The findings of this study provide theoretical support for clinical tissue engineering applications and improvements in stem cell therapy.
大面积软组织缺损的外科重建极具挑战性。使用外部容量扩张（EVE）装置扩张软组织是改善这种重建的一种非侵入性方法，但潜在的机制尚不清楚。在这项研究中，我们在 Sprague-Dawley 大鼠中创建了脂肪皮瓣，使用 EVE 装置施加 3 或 6kPa 的外部力，并研究了脂肪源性干细胞/祖细胞（ASCs）的迁移和分化。此外，我们进行了有限元分析以探索脂肪组织的硬度。3kPa 的外部力促进了 ASCs 的迁移和脂肪生成分化。相比之下，6kPa 的外部力对 ASCs 的迁移有更大的影响，但对 ASCs 的脂肪生成分化的影响较小。外部力会影响脂肪组织的硬度。总之，EVE 装置产生的外部力会增加脂肪组织的硬度，从而影响 ASCs 的迁移和分化。可以根据特定时间点所需的组织硬度来改变外部力的大小，以促进长期的脂肪组织再生。
