pH-Sensitive Coiled-Coil Peptide-Cross-Linked Hyaluronic Acid Nanogels: Synthesis and Targeted Intracellular Protein Delivery to CD44 Positive Cancer Cells

Lingling Ding^†,Yu Jiang^†,Jian Zhang^*†（张建）,Harm-Anton Klok^†‡, andZhiyuan Zhong^*†（钟志远）

^†Biomedical Polymers Laboratory, and Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science,Soochow University, Suzhou, 215123,People’s Republic of China

^‡Laboratoire des Polymères,Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne,Switzerland

Biomacromolecules,2018,19(2), 555--562

The clinical translation of protein drugs that act intracellularly is limited by the absence of safe and efficient intracellular protein delivery vehicles. Here, pH-sensitive coiled-coil peptide-cross-linked hyaluronic acid nanogels (HA-cNGs) were designed and investigated for targeted intracellular protein delivery to CD44 overexpressing MCF-7 breast cancer cells. HA-cNGs were obtained with a small size of 176 nm from an equivalent mixture of hyaluronic acid conjugates with GY(EIAALEK)₃GC (E3) and GY(KIAALKE)₃GC (K3) peptides, respectively, at pH 7.4 by nanoprecipitation. Circular dichroism (CD) proved the formation of coiled-coil structures between E3 and K3 peptides at pH 7.4 while fast uncoiling at pH 5.0. HA-cNGs showed facile loading of cytochrome C (CC) and greatly accelerated CC release under mild acidic conditions (18.4%, 76.8%, and 91.4% protein release in 24 h at pH 7.4, 6.0, and 5.0, respectively). Confocal microscopy and flow cytometry displayed efficient internalization of CC-loaded HA-cNGs and effective endosomal escape of CC in MCF-7 cancer cells. Remarkably, HA-cNGs loaded with saporin, a ribosome inactivating protein, exhibited significantly enhanced apoptotic activity to MCF-7 cells with a low IC₅₀of 12.2 nM. These coiled-coil peptide-cross-linked hyaluronic acid nanogels have appeared as a simple and multifunctional platform for efficient intracellular protein delivery.

链接：https://pubs.acs.org/doi/10.1021/acs.biomac.7b01664