A radiopaque electrospun scaffold for engineering fibrous musculoskeletal tissues: Scaffold characterization and in vivo applications.
A radiopaque electrospun scaffold for engineering fibrous musculoskeletal tissues: Scaffold characterization and in vivo applications.
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DOI：
10.1016/j.actbio.2015.08.001
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发表时间：
2015-10
影响因子：
9.7
通讯作者：
Mauck RL
中科院分区：
文献类型：
--
作者：
Martin JT;Milby AH;Ikuta K;Poudel S;Pfeifer CG;Elliott DM;Smith HE;Mauck RL
组织工程策略的出现是为了应对慢性肌肉骨骼疾病的日益流行，其中许多再生方法目前正在转化动物模型中进行评估。纤维组织（例如半月板、纤维环、肌腱和韧带）的工程替代物要承受具有挑战性的生理负荷，并且很难使用标准技术在体内进行追踪。肌肉骨骼疾病的诊断和治疗在很大程度上取决于射线照相评估，并且许多当前可用的植入物利用不透射线标记物来促进体内成像。在这项研究中，我们开发了一种纳米纤维支架，其中单个纤维包含不透射线的纳米颗粒。包含不透射线的颗粒增加了支架的拉伸模量，并在皮质骨范围内产生辐射衰减。当支架在体外接种牛间充质干细胞时，细胞增殖没有变化，也没有混杂转化为成骨表型的证据。将支架离体植入牛关节半月板撕裂模型中，并在体内植入大鼠尾骨脊柱（尾部）全椎间盘置换模型中，并通过荧光镜和微型计算机断层扫描进行可视化。在椎间盘置换模型中，4周时的组织学分析表明支架具有生物相容性并支持体内纤维组织的沉积。因此，包括不透射线纳米颗粒的纳米纤维支架提供了具有足够的不透射线性的生物相容性模板，用于小型和大型动物模型中的体内可视化。这种射线不透性可以促进图像引导植入以及对支架位置和性能的非侵入性长期评估。
Tissue engineering strategies have emerged in response to the growing prevalence of chronic musculoskeletal conditions, and many of these regenerative methods are currently being evaluated in translational animal models. Engineered replacements for fibrous tissues such as the meniscus, annulus fibrosus, tendons, and ligaments are subjected to challenging physiologic loads, and are difficult to track in vivo using standard techniques. The diagnosis and treatment of musculoskeletal conditions depends heavily on radiographic assessment, and a number of currently available implants utilize radiopaque markers to facilitate in vivo imaging. In this study, we developed a nanofibrous scaffold in which individual fibers included radiopaque nanoparticles. Inclusion of radiopaque particles increased the tensile modulus of the scaffold and imparted radiation attenuation within the range of cortical bone. When scaffolds were seeded with bovine mesenchymal stem cells in vitro, there was no change in cell proliferation and no evidence of promiscuous conversion to an osteogenic phenotype. Scaffolds were implanted ex vivo in a model of a meniscal tear in a bovine joint and in vivo in a model of total disc replacement in the rat coccygeal spine (tail), and were visualized via fluoroscopy and microcomputed tomography. In the disc replacement model, histological analysis at 4 weeks showed that the scaffold was biocompatible and supported the deposition of fibrous tissue in vivo. Thus, nanofibrous scaffolds including radiopaque nanoparticles provide a biocompatible template with sufficient radiopacity for in vivo visualization in both small and large animal models. This radiopacity may facilitate image-guided implantation and non-invasive long-term evaluation of scaffold location and performance.