Xing Qi, Vogt Caleb, Leong Kam W, Zhao Feng
Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931.
Department of Biomedical Engineering, Duke University, Durham, NC 49931.
Adv Funct Mater. 2014 May 28;24(20):3027-3035. doi: 10.1002/adfm.201303460.
Native tissues are endowed with a highly organized nanofibrous extracellular matrix (ECM) that directs cellular distribution and function. The objective of this study is to create a purely natural, uniform, and highly aligned nanofibrous ECM scaffold for potential tissue engineering applications. Synthetic nanogratings (130 nm in depth) were used to direct the growth of human dermal fibroblasts for up to 8 weeks, resulting in a uniform 70 μm-thick fibroblast cell sheet with highly aligned cells and ECM nanofibers. A natural ECM scaffold with uniformly aligned nanofibers of 78 ± 9 nm in diameter was generated after removing the cellular components from the detached fibroblast sheet. The elastic modulus of the scaffold was well maintained after the decellularization process because of the preservation of elastin fibers. Reseeding human mesenchymal stem cells (hMSCs) showed the excellent capacity of the scaffold in directing and supporting cell alignment and proliferation along the underlying fibers. The scaffold's biocompatibility was further examined by an inflammation assay with seeded macrophages. The aligned ECM scaffold induced a significantly lower immune response compared to its unaligned counterpart, as detected by the pro-inflammatory cytokines secreted from macrophages. The aligned nanofibrous ECM scaffold holds great potential in engineering organized tissues.
天然组织具有高度有序的纳米纤维细胞外基质(ECM),它指导细胞的分布和功能。本研究的目的是创建一种纯天然、均匀且高度排列的纳米纤维ECM支架,用于潜在的组织工程应用。利用合成纳米光栅(深度为130纳米)引导人真皮成纤维细胞生长长达8周,形成了一个均匀的、70微米厚的成纤维细胞片,其中细胞和ECM纳米纤维高度排列。从脱离的成纤维细胞片中去除细胞成分后,生成了一种天然ECM支架,其纳米纤维直径均匀排列,为78±9纳米。由于弹性纤维的保留,脱细胞过程后支架的弹性模量得到了很好的维持。重新接种人间充质干细胞(hMSCs)显示出该支架在引导和支持细胞沿底层纤维排列和增殖方面具有出色的能力。通过接种巨噬细胞的炎症试验进一步检测了支架的生物相容性。与未排列的对应物相比,排列的ECM支架诱导的免疫反应明显更低,这通过巨噬细胞分泌的促炎细胞因子检测到。排列的纳米纤维ECM支架在构建有组织的组织方面具有巨大潜力。