Design and synthesis of biodegradable nonconjugated S-S-PAMAM dendrimers with unexpected Deep-red/NIR emission and cell membrane targeting ability for biological imaging
Design and synthesis of biodegradable nonconjugated S-S-PAMAM dendrimers with unexpected Deep-red/NIR emission and cell membrane targeting ability for biological imaging
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DOI：
10.1016/j.matdes.2022.110982
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发表时间：
2022-07-30
影响因子：
8.4
通讯作者：
Lei, Zi-qiang
中科院分区：
文献类型：
--
作者：
Guan, Xiao-lin;Yang, Xue-qin;Lei, Zi-qiang
不含对位芳香结构单元的荧光非共轭聚合物具有低细胞毒性和良好的生物相容性，在生物应用中具有重要意义。然而，要实现明亮的深红色/近红外（NIR）发射仍然是一个巨大的挑战。在此，我们设计并合成了一系列基于二硫键连接的聚酰胺-胺（S-S-PAMAM）树枝状分子的聚集诱导发射的深红色/近红外非共轭聚合物，它们具有优异的生物降解性，可用于生物成像。通过引入胱胺代替普通的双丙烯酰胺，以高产率合成了主链含有二硫键的S-S-PAMAM树枝状大分子（G0.5-G2.0）。出乎意料的是，制备的S-S-PAMAM树枝状聚合物表现出明亮的和激发依赖的多色可调谐发射。更有趣的是，G2.0 S-S-PAMAM显示出深红色/NIR发射（kem = 625 nm，在800 nm处具有肩部），其来源于通过强分子内氢键形成的非常刚性和紧凑的构象。同时，这些树枝状大分子显示出良好的生物降解性，因为大量的二硫键的骨干。由于具有良好的细胞膜定位特异性，S-S-PAMAM树枝状聚合物可用作多色（蓝色、绿色和深红）成像的潜在细胞膜成像试剂。此外，它们还可以用于斑马鱼的生物成像。这一研究拓展了荧光非共轭聚合物在长波长活体生物成像领域的应用。(c)2022年，任作家。由Elsevier Ltd.发布。这是CC BY许可下的开放获取文章（http：//creativecommons.org/licenses/by/4.0/）。
Fluorescent non-conjugated polymers without any p-aromatic building blocks are of great significance in biological applications due to low cytotoxicity and good biocompatibility. However, it is still a great chal-lenge to achieve bright and deep-red/near-infrared (NIR) emissions. Herein, we have designed and syn-thesized a series of deep-red/NIR non-conjugated polymers with aggregation-induced emission based on disulfide-linked poly(amidoamine) (S-S-PAMAM) dendrimers, which exhibit excellent biodegradation for bioimaging. These S-S-PAMAM dendrimers (G0.5-G2.0) containing disulfide bonds in their backbone were synthesized in high yield by incorporating cystamine instead of common diacrylamide. Unexpectedly, the S-S-PAMAM dendrimers prepared exhibited bright and excitation dependent multicolor-tunable emission. More interestingly, G2.0 S-S-PAMAM showed a deep-red/NIR emission (kem = 625 nm with a shoulder at 800 nm) originated from an extraordinarily rigid and compact confor-mation via strong intramolecular hydrogen bonds. Meanwhile, these dendrimers displayed excellent biodegradability because of the large number of disulfide linkages in backbone. Due to the excellent specific cytomembrane location, S-S-PAMAM dendrimers can be used as a potential cell membrane imaging reagent for multi-color (blue, green, and deep-red) imaging. Furthermore, they could also be used in zebrafish for bioimaging. This investigation has expanded the applications of fluorescent non -conjugated polymers to the field of long-wavelength in vivo biological imaging.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).