Nanocomposite Scaffold for Chondrocyte Growth and Cartilage Tissue Engineering: Effects of Carbon Nanotube Surface Functionalization
Nanocomposite Scaffold for Chondrocyte Growth and Cartilage Tissue Engineering: Effects of Carbon Nanotube Surface Functionalization
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DOI：
10.1089/ten.tea.2013.0328
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发表时间：
2014-09-01
影响因子：
4.1
通讯作者：
Loots, Gabriela G.
中科院分区：
文献类型：
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作者：
Chahine, Nadeen O.;Collette, Nicole M.;Loots, Gabriela G.
本研究的目的是评估单壁碳纳米管（SWNTs）用于组织工程关节软骨的长期生物相容性。我们假设，单壁碳纳米管纳米复合材料支架在软骨组织工程中可以提供一个改进的分子大小的基板，刺激软骨细胞的生长，以及支架的机械性能的结构增强。单壁碳纳米管表面功能化（-COOH或-PEG）对软骨细胞活力和生化基质沉积的影响进行了研究，在二维培养，在三维（3D）小球培养，并在3D纳米复合材料支架组成的水凝胶+单壁碳纳米管。结果测量包括细胞活力、组织学和SEM评价、GAG生物化学含量、压缩和拉伸生物力学性质以及基因表达定量，包括细胞外基质（ECM）标记物聚集蛋白聚糖（Agc）、胶原蛋白-1（Col 1a 1）、胶原蛋白-2（Col 2a 1）、胶原蛋白-10（Col 10a 1）、表面粘附蛋白纤连蛋白（Fn）、CD 44抗原（CD 44）、和肿瘤标志物（Tp 53）。我们的研究结果表明，软骨细胞耐受功能化的单壁碳纳米管，在三维培养系统（小球和纳米复合材料结构）的细胞毒性最小。相对于对照，SWNT-PEG和SWNT-COOH基团都增加了纳米复合材料中的GAG含量。细胞负载的SWNT-COOH纳米复合材料的压缩生物力学性能相对于对照显著升高。观察到拉伸模量和极限应力的增加，表明纳米复合材料支架的拉伸增强。表面涂层的单壁碳纳米管与-COOH也导致增加的Col 2a 1和Fn基因的表达在整个培养中的纳米复合材料的结构，增加软骨细胞的代谢活性的指示。相比之下，用中性-PEG部分涂覆SWNT的表面对Col 2a 1或Fn基因表达没有显著影响，表明-COOH表面功能化的带电性质可以促进该培养系统中的ECM表达。这项研究的结果表明，单壁碳纳米管表现出独特的潜力，软骨组织工程，其中与生物活性分子的功能化可以提供一个改进的基板刺激细胞的生长和修复。
The goal of this study was to assess the long-term biocompatibility of single-wall carbon nanotubes (SWNTs) for tissue engineering of articular cartilage. We hypothesized that SWNT nanocomposite scaffolds in cartilage tissue engineering can provide an improved molecular-sized substrate for stimulation of chondrocyte growth, as well as structural reinforcement of the scaffold's mechanical properties. The effect of SWNT surface functionalization (-COOH or -PEG) on chondrocyte viability and biochemical matrix deposition was examined in two-dimensional cultures, in three-dimensional (3D) pellet cultures, and in a 3D nanocomposite scaffold consisting of hydrogels + SWNTs. Outcome measures included cell viability, histological and SEM evaluation, GAG biochemical content, compressive and tensile biomechanical properties, and gene expression quantification, including extracellular matrix (ECM) markers aggrecan (Agc), collagen-1 (Col1a1), collagen-2 (Col2a1), collagen-10 (Col10a1), surface adhesion proteins fibronectin (Fn), CD44 antigen (CD44), and tumor marker (Tp53). Our findings indicate that chondrocytes tolerate functionalized SWNTs well, with minimal toxicity of cells in 3D culture systems (pellet and nanocomposite constructs). Both SWNT-PEG and SWNT-COOH groups increased the GAG content in nanocomposites relative to control. The compressive biomechanical properties of cell-laden SWNT-COOH nanocomposites were significantly elevated relative to control. Increases in the tensile modulus and ultimate stress were observed, indicative of a tensile reinforcement of the nanocomposite scaffolds. Surface coating of SWNTs with -COOH also resulted in increased Col2a1 and Fn gene expression throughout the culture in nanocomposite constructs, indicative of increased chondrocyte metabolic activity. In contrast, surface coating of SWNTs with a neutral -PEG moiety had no significant effect on Col2a1 or Fn gene expression, suggesting that the charged nature of the -COOH surface functionalization may promote ECM expression in this culture system. The results of this study indicate that SWNTs exhibit a unique potential for cartilage tissue engineering, where functionalization with bioactive molecules may provide an improved substrate for stimulation of cellular growth and repair.