Biomolecular Functionalization of a Nanomaterial To Control Stability and Retention within Live Cells
Biomolecular Functionalization of a Nanomaterial To Control Stability and Retention within Live Cells
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DOI：
10.1021/acs.nanolett.9b02267
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发表时间：
2019-09-01
期刊：
影响因子：
10.8
通讯作者：
Roxbury, Daniel
中科院分区：
文献类型：
--
作者：
Gravely, Mitchell;Safaee, Mohammad Moein;Roxbury, Daniel
单链DNA和单壁碳纳米管（SWCNT）的非共价杂交物由于其增强的生物相容性和光稳定性、环境响应的近红外（NIR）荧光而在生物医学成像和传感中显示出应用。这样的DNA-SWCNT的基本属性进行了研究，以确定寡核苷酸序列和长度，SWCNT种类，和所得的杂交种的物理属性之间的相关关系。然而，细胞内环境引入了苛刻的条件，可以改变混合纳米材料的物理特性，从而改变其固有的光学性质。在这里，通过可见光和近红外荧光成像，除了共聚焦拉曼显微镜，我们表明，寡核苷酸长度控制相对摄取，细胞内的光学稳定性，并保留DNA-SWCNTs在哺乳动物细胞。尽管小鼠巨噬细胞中DNA-SWCNT的绝对NIR荧光强度随着寡核苷酸长度的增加（从12到60个核苷酸）而增加，但我们发现较短的寡核苷酸DNA-SWCNT经历更大幅度的光谱偏移，并且在24小时后更快速地内化并从细胞中排出。此外，通过用荧光团标记DNA，在从SWCNT表面去除后去猝灭，我们发现较短的寡核苷酸链从细胞内的SWCNT中被置换，改变了物理特性并改变了内化纳米材料的命运。最后，通过药理学抑制研究，我们确定了单壁碳纳米管从细胞中排出的机制为溶酶体胞吐作用。这些发现提供了对单壁碳纳米管和活细胞之间相互作用的基本理解，以及表明仅通过改变DNA包裹类型来控制纳米材料的生物命运的能力的证据。
Noncovalent hybrids of single-stranded DNA and single-walled carbon nanotubes (SWCNTs) have demonstrated applications in biomedical imaging and sensing due to their enhanced biocompatibility and photostable, environmentally responsive near-infrared (NIR) fluorescence. The fundamental properties of such DNA-SWCNTs have been studied to determine the correlative relationships between oligonucleotide sequence and length, SWCNT species, and the physical attributes of the resultant hybrids. However, intracellular environments introduce harsh conditions that can change the physical identities of the hybrid nanomaterials, thus altering their intrinsic optical properties. Here, through visible and NIR fluorescence imaging in addition to confocal Raman microscopy, we show that the oligonucleotide length controls the relative uptake, intracellular optical stability, and retention of DNA-SWCNTs in mammalian cells. Although the absolute NIR fluorescence intensity of DNA-SWCNTs in murine macrophages increases with increasing oligonucleotide length (from 12 to 60 nucleotides), we found that shorter oligonucleotide DNA-SWCNTs undergo a greater magnitude of spectral shift and are more rapidly internalized and expelled from the cell after 24 h. Furthermore, by labeling the DNA with a fluorophore that dequenches upon removal from the SWCNT surface, we found that shorter oligonucleotide strands are displaced from the SWCNT within the cell, altering the physical identity and changing the fate of the internalized nanomaterial. Finally, through a pharmacological inhibition study, we identified the mechanism of SWCNT expulsion from the cells as lysosomal exocytosis. These findings provide a fundamental understanding of the interactions between SWCNTs and live cells as well as evidence suggesting the ability to control the biological fate of the nanomaterials merely by varying the type of DNA wrapping.