BACKGROUND:Adipose tissue engineering has been studied as an alternative to current options for breast reconstruction, such as lipofilling, flap reconstruction, and silicone implants. Previously, we demonstrated that a poly(L-lactic acid) mesh containing a collagen sponge, containing neither cellsnor growth factors, could be filled with the regenerated adipose tissues when implanted in rodent models. However, the main factor contributing to adipogenesis remained unclear. OBJECTIVE:We aimed to clarify whether adipogenesis can be achieved by the space provided by the mesh or by the bioactivity of collagen. METHODS:A three-dimensional (3D) poly(lactic acid) (PLA) frame, which was stiff enough to maintain its shape, was fabricated by 3D printing. The frame with (PLA+ColI) or without (PLA only) a type I collagen hydrogel was implanted in the inguinal region of rats for up to 12 months. Adipose tissue regeneration in the PLA only and PLA+ColI groups was evaluated histologically. RESULTS:The 3D PLA frame maintained its structure for 12 months in vivo and oil red O (ORO)-positive adipose tissues were regenerated in the frame. No significant difference in the ORO-positive area was detected between the PLA only and PLA+ColI groups. CONCLUSION:The space supported by the frame was a key factor in adipogenesis in vivo.

中文翻译：

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大鼠腹股沟区 3D 打印聚乳酸框架支撑空间中的脂肪组织再生。

背景：脂肪组织工程已被研究作为当前乳房重建选择的替代方案，例如脂肪填充、皮瓣重建和硅胶植入物。以前，我们证明了含有胶原海绵的聚（L-乳酸）网状物，既不含细胞也不含生长因子，当植入啮齿动物模型时，可以填充再生脂肪组织。然而，导致脂肪生成的主要因素仍不清楚。目的：我们旨在阐明是否可以通过网提供的空间或胶原蛋白的生物活性来实现脂肪生成。方法：通过 3D 打印制造了一个三维 (3D) 聚乳酸 (PLA) 框架，其硬度足以保持其形状。将含有（PLA+ColI）或不含（仅 PLA）I 型胶原水凝胶的框架植入大鼠腹股沟区长达 12 个月。仅对 PLA 和 PLA+ColI 组中的脂肪组织再生进行了组织学评估。结果：3D PLA框架在体内保持其结构12个月，并且在框架中再生了油红O（ORO）阳性脂肪组织。在仅 PLA 和 PLA+ColI 组之间未检测到 ORO 阳性区域的显着差异。结论：框架支撑的空间是体内脂肪生成的关键因素。在仅 PLA 和 PLA+ColI 组之间未检测到 ORO 阳性区域的显着差异。结论：框架支撑的空间是体内脂肪生成的关键因素。在仅 PLA 和 PLA+ColI 组之间未检测到 ORO 阳性区域的显着差异。结论：框架支撑的空间是体内脂肪生成的关键因素。