Journal of nanobiotechnology, cilt.18, ss.65, 2020 (SCI-Expanded)
Nanoparticle based gene delivery systems holds great promise. Superparamagnetic iron oxide nanoparticles (SPIONs)
are being heavily investigated due to good biocompatibility and added diagnostic potential, rendering such nanoparticles theranostic. Yet, commonly used cationic coatings for efficient delivery of such anionic cargos, results in
significant toxicity limiting translation of the technology to the clinic. Here, we describe a highly biocompatible, small
and non-cationic SPION-based theranostic nanoparticles as novel gene therapy agents. We propose for the first-time,
the usage of the microRNA machinery RISC complex component Argonaute 2 (AGO2) protein as a microRNA stabilizing agent and a delivery vehicle. In this study, AGO2 protein-conjugated, anti-HER2 antibody-linked and fuorophoretagged SPION nanoparticles were developed (SP-AH nanoparticles) and used as a carrier for an autophagy inhibitory
microRNA, MIR376B. These functionalized nanoparticles selectively delivered an effective amount of the microRNA
into HER2-positive breast cancer cell lines in vitro and in a xenograft nude mice model of breast cancer in vivo, and
successfully blocked autophagy. Furthermore, combination of the chemotherapy agent cisplatin with MIR376B-loaded
SP-AH nanoparticles increased the efficacy of the anti-cancer treatment both in vitro in cells and in vivo in the nude
mice. Therefore, we propose that AGO2 protein conjugated SPIONs are a new class of theranostic nanoparticles and
can be efficiently used as innovative, non-cationic, non-toxic gene therapy tools for targeted therapy of cancer.