Self-assembled quantum dot-peptide bioconjugates for selective intracellular delivery
Self-assembled quantum dot-peptide bioconjugates for selective intracellular delivery
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DOI：
10.1021/bc060044i
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发表时间：
2006-07-19
影响因子：
4.7
通讯作者：
Mattoussi, Hedi
中科院分区：
文献类型：
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作者：
Delehanty, James B.;Medintz, Igor L.;Mattoussi, Hedi
我们展示了使用自组装发光半导体量子点（QD）-肽生物缀合物对几种真核细胞系进行选择性细胞内标记。合成了带有末端多组氨酸束的双功能寡精氨酸细胞穿透肽（基于 HIV-1 Tat 蛋白基序），并用于促进 QD 生物缀合物的跨膜递送。与非共轭 QD 相比，多组氨酸序列允许肽通过金属亲和力相互作用自组装到 QD 表面，而寡精氨酸序列允许特异性 QD 跨细胞膜递送和细胞内标记。这种肽驱动的递送具有浓度依赖性，因此可以进行滴定。内化后，QD 显示出点状染色模式，其中部分（但不是全部）QD 信号共定位于核内体内。通过代谢特异性测定评估持续接触 QD-肽缀合物与有限接触 QD-肽缀合物对细胞活力的影响，并观察到细胞毒性的明显差异。通过进行多色 QD 标记，突出了使用肽进行选择性细胞内递送的功效，我们发现 QD 表面上肽的存在或不存在控制着细胞的摄取。
We demonstrate the use of self-assembled luminescent semiconductor quantum dot (QD)-peptide bioconjugates for the selective intracellular labeling of several eukaryotic cell lines. A bifunctional oligoarginine cell penetrating peptide (based on the HIV-1 Tat protein motif) bearing a terminal polyhistidine tract was synthesized and used to facilitate the transmembrane delivery of the QD bioconjugates. The polyhistidine sequence allows the peptide to self-assemble onto the QD surface via metal-affinity interactions while the oligoarginine sequence allows specific QD delivery across the cellular membrane and intracellular labeling as compared to nonconjugated QDs. This peptide-driven delivery is concentration-dependent and thus can be titrated. Upon internalization, QDs display a punctate-like staining pattern in which some, but not all, of the QD signal is colocalized within endosomes. The effects of constant versus limited exposure to QD-peptide conjugates on cellular viability are evaluated by a metabolic specific assay, and clear differences in cytotoxicity are observed. The efficacy of using peptides for selective intracellular delivery is highlighted by performing a multicolor QD labeling, where we found that the presence or absence of peptide on the QD surface controls cellular uptake.