Department of General Practice, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, People's Republic of China; Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE, USA; Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE, USA; College of Textiles & Clothing, Qingdao University, Qingdao, People's Republic of China.
Acta Biomater. 2018 Jul 1;74:131-142. doi: 10.1016/j.actbio.2018.05.044. Epub 2018 May 26.
Bioengineered adipose tissues have gained increased interest as a promising alternative to autologous tissue flaps and synthetic adipose fillers for soft tissue augmentation and defect reconstruction in clinic. Although many scaffolding materials and biofabrication methods have been investigated for adipose tissue engineering in the last decades, there are still challenges to recapitulate the appropriate adipose tissue microenvironment, maintain volume stability, and induce vascularization to achieve long-term function and integration. In the present research, we fabricated cryogels consisting of methacrylated gelatin, methacrylated hyaluronic acid, and 4arm poly(ethylene glycol) acrylate (PEG-4A) by using cryopolymerization. The cryogels were repeatedly injectable and stretchable, and the addition of PEG-4A improved the robustness and mechanical properties. The cryogels supported human adipose progenitor cell (HWA) and adipose derived mesenchymal stromal cell adhesion, proliferation, and adipogenic differentiation and maturation, regardless of the addition of PEG-4A. The HWA laden cryogels facilitated the co-culture of human umbilical vein endothelial cells (HUVEC) and capillary-like network formation, which in return also promoted adipogenesis. We further combined cryogels with 3D bioprinting to generate handleable adipose constructs with clinically relevant size. 3D bioprinting enabled the deposition of multiple bioinks onto the cryogels. The bioprinted flap-like constructs had an integrated structure without delamination and supported vascularization.
Adipose tissue engineering is promising for reconstruction of soft tissue defects, and also challenging for restoring and maintaining soft tissue volume and shape, and achieving vascularization and integration. In this study, we fabricated cryogels with mechanical robustness, injectability, and stretchability by using cryopolymerization. The cryogels promoted cell adhesion, proliferation, and adipogenic differentiation and maturation of human adipose progenitor cells and adipose derived mesenchymal stromal cells. Moreover, the cryogels also supported 3D bioprinting on top, forming vascularized adipose constructs. This study demonstrates the potential of the implementation of cryogels for generating volume-stable adipose tissue constructs and provides a strategy to fabricate vascularized flap-like constructs for complex soft tissue regeneration.
生物工程化的脂肪组织作为自体组织皮瓣和合成脂肪填充物的替代物，在临床上用于软组织填充和缺损重建，其应用日益受到关注。尽管在过去几十年中，已经有许多支架材料和生物制造方法被用于脂肪组织工程，但仍然存在一些挑战，例如难以重现适当的脂肪组织微环境、维持体积稳定性以及诱导血管生成，以实现长期功能和整合。在本研究中，我们通过冷冻聚合制备了由甲基丙烯酰化明胶、甲基丙烯酰化透明质酸和 4 臂聚乙二醇丙烯酸酯（PEG-4A）组成的冷冻凝胶。这些冷冻凝胶可重复注射和拉伸，并且添加 PEG-4A 可提高其稳定性和机械性能。冷冻凝胶支持人脂肪祖细胞（HWA）和脂肪来源间充质基质细胞的黏附、增殖和脂肪生成分化及成熟，无论是否添加 PEG-4A。负载 HWA 的冷冻凝胶促进了人脐静脉内皮细胞（HUVEC）的共培养和毛细血管样网络的形成，这反过来也促进了脂肪生成。我们进一步将冷冻凝胶与 3D 生物打印相结合，生成具有临床相关尺寸的可处理的脂肪构建体。3D 生物打印可以将多种生物墨水沉积到冷冻凝胶上。打印的瓣状构建体具有集成结构，没有分层，并支持血管生成。
脂肪组织工程在软组织缺损的重建方面具有广阔的应用前景，但同时也面临着一些挑战，如恢复和维持软组织体积和形状、实现血管生成和整合等。在本研究中，我们通过冷冻聚合制备了具有机械强度、可注射性和可拉伸性的冷冻凝胶。该冷冻凝胶促进了人脂肪祖细胞和脂肪来源间充质基质细胞的黏附、增殖和脂肪生成分化及成熟。此外，该冷冻凝胶还支持在其表面进行 3D 生物打印，形成血管化的脂肪构建体。本研究证明了冷冻凝胶在生成体积稳定的脂肪组织构建体方面的潜力，并为制造用于复杂软组织再生的血管化瓣状构建体提供了一种策略。
