Reinforcement of Mono- and Bi-layer Poly(Ethylene Glycol) Hydrogels with a Fibrous Collagen Scaffold.
Reinforcement of Mono- and Bi-layer Poly(Ethylene Glycol) Hydrogels with a Fibrous Collagen Scaffold.
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DOI：
10.1007/s10439-015-1337-0
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发表时间：
2015-11
影响因子：
3.8
通讯作者：
Ferguson VL
中科院分区：
文献类型：
--
作者：
Kinneberg KR;Nelson A;Stender ME;Aziz AH;Mozdzen LC;Harley BA;Bryant SJ;Ferguson VL
基于生物材料的组织工程策略在骨软骨组织修复方面具有巨大的潜力。然而，在连接差异很大的材料以实现一种仿生的、机械性能良好的用于修复软组织和骨之间界面的设计方面，仍然存在重大挑战。本研究旨在改善一种与纤维状胶原蛋白支架相互贯穿的双层、多相水凝胶的界面特性和功能。将10%（w/w）的“软”聚乙二醇二甲基丙烯酸酯（PEGDM）和30%（w/w）的“硬”PEGDM制成具有明显扩散界面的单层或双层水凝胶。水凝胶被评估为单相（仅水凝胶）或多相（水凝胶 + 纤维支架贯穿整个硬层并延伸到软层大于500μm）。在软的和硬的单相水凝胶中加入纤维支架显著提高了切线模量和韧性，并降低了压缩载荷下的横向膨胀。在多相水凝胶中，有限元模拟预测在软硬水凝胶界面处的应力和应变梯度大幅降低。当组合两种低模量的组成材料时，复合材料理论很难预测所观察到的大的模量增加。这些结果表明，与纤维支架在PEG水凝胶内贯穿相关的材料结构是改善性能和功能的主要因素——水凝胶承受压缩载荷，3D纤维支架承受拉力，从而抵抗横向膨胀。
Biomaterial-based tissue engineering strategies hold great promise for osteochondral tissue repair. Yet significant challenges remain in joining highly dissimilar materials to achieve a biomimetic, mechanically robust design for repairing interfaces between soft tissue and bone. This study sought to improve interfacial properties and function in a bilayer, multi-phase hydrogel interpenetrated with a fibrous collagen scaffold. ‘Soft’ 10% (w/w) and ‘stiff’ 30% (w/w) PEGDM was formed into mono- or bilayer hydrogels possessing a sharp diffusional interface. Hydrogels were evaluated as single- (hydrogel only) or multi-phase (hydrogel+fibrous scaffold penetrating throughout the stiff layer and extending >500μm into the soft layer). Including a fibrous scaffold into both soft and stiff single-phase hydrogels significantly increased tangent modulus and toughness and decreased lateral expansion under compressive loading. In multi-phase hydrogels, finite element simulations predict substantially reduced stress and strain gradients across the soft—stiff hydrogel interface. When combining two low moduli constituent material, composites theory poorly predicts the observed, large modulus increases. These results suggest material structure associated with the fibrous scaffold penetrating within the PEG hydrogel as the major contributor to improved properties and function – the hydrogel bore compressive loads and the 3D fibrous scaffold was loaded in tension thus resisting lateral expansion.