Cellular Uptake of Substrate-Initiated Cell-Penetrating Poly(disulfide)s

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• 作者：Giulio Gasparini ; Eun-Kyoung Bang ; Guillaume Molinard ; David V. Tulumello ; Sandra Ward ; Shana O. Kelley ; Aurelien Roux ; Naomi Sakai ; Stefan Matile
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：April 23, 2014
• 年：2014
• 卷：136
• 期：16
• 页码：6069-6074
• 全文大小：371K
• 年卷期：v.136,no.16(April 23, 2014)
• ISSN：1520-5126

文摘

Substrate-initiated, self-inactivating, cell-penetrating poly(disulfide)s (siCPDs) are introduced as general transporters for the covalent delivery of unmodified substrates of free choice. With ring-opening disulfide-exchange polymerization, we show that guanidinium-rich siCPDs grow on fluorescent substrates within minutes under the mildest conditions. The most active siCPD transporters reach the cytosol of HeLa cells within 5 min and depolymerize in less than 1 min to release the native substrate. Depolymerized right after use, the best siCPDs are nontoxic under conditions where cell-penetrating peptides (CPPs) are cytotoxic. Intracellular localization (cytosol, nucleoli, endosomes) is independent of the substrate and can be varied on demand, through choice of polymer composition. Insensitivity to endocytosis inhibitors and classical structural variations (hydrophobicity, aromaticity, branching, boronic acids) suggest that the best siCPDs act differently. Supported by experimental evidence, a unique combination of the counterion-mediated translocation of CPPs with the underexplored, thiol-mediated covalent translocation is considered to account for this decisive difference.