Dual-pH Sensitive Charge-Reversal Polypeptide Micelles for Tumor-Triggered Targeting Uptake and Nuclear Drug Delivery.

Abstract

A novel dual-pH sensitive charge-reversal strategy is designed to deliver antitumor drugs targeting to tumor cells and to further promote the nuclei internalization by a stepwise response to the mildly acidic extracellular pH (≈6.5) of a tumor and endo/lysosome pH (≈5.0). Poly(L-lysine)-block-poly(L-leucine) diblock copolymer is synthesized and the lysine amino residues are amidated by 2,3-dimethylmaleic anhydride to form β-carboxylic amide, making the polypeptides self-assemble into negatively charged micelles. The amide can be hydrolyzed when exposed to the mildly acidic tumor extracellular environment, which makes the micelles switch to positively charged and they are then readily internalized by tumor cells. A nuclear targeting Tat peptide is further conjugated to the polypeptide via a click reaction. The Tat is amidated by succinyl chloride to mask its positive charge and cell-penetrating function and thus to inhibit nonspecific cellular uptake. After the nanoparticles are internalized into the more acidic intracellular endo/lysosomes, the Tat succinyl amide is hydrolyzed to reactivate the Tat nuclear targeting function, promoting nanoparticle delivery into cell nuclei. This polypeptide nanocarrier facilitates tumor targeting and nuclear delivery simultaneously by simply modifying the lysine amino residues of polylysine and Tat into two different pH-sensitive β-carboxylic amides.

• Authors: Shi-Song Han, Ze-Yong Li, Jing-Yi Zhu, Kai Han, Zheng-Yang Zeng, Wei Hong, Wen-Xin Li, Hui-Zhen Jia, Yun Liu, Ren-Xi Zhuo, Xian-Zheng Zhang
• Journal: Small (Weinheim an der Bergstrasse, Germany) (Small) Vol. 11 Issue 21 Pg. 2543-54 (Jun 03 2015) ISSN: 1613-6829 [Electronic] Germany
• PMID: 25626995 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical References

• Antineoplastic Agents
• Drug Carriers
• Micelles
• Peptides
• tat Gene Products, Human Immunodeficiency Virus
• Polylysine
• polyleucine
• Doxorubicin

Topics

• Active Transport, Cell Nucleus
• Antineoplastic Agents (administration & dosage, pharmacokinetics)
• Cell Nucleus (drug effects)
• Cell Survival (drug effects)
• Doxorubicin (administration & dosage, pharmacokinetics)
• Drug Carriers (chemistry)
• Drug Delivery Systems
• HeLa Cells
• Humans
• Hydrogen-Ion Concentration
• Micelles
• Nanoparticles (chemistry)
• Peptides (chemical synthesis, chemistry)
• Polylysine (chemistry)
• Protein Multimerization
• tat Gene Products, Human Immunodeficiency Virus (chemistry)