Study and Preparation of Multifunctional Poly(L-Lysine)@Hyaluronic Acid Nanopolyplexes for the Effective Delivery of Tumor Suppressive MiR-34a into Triple-Negative Breast Cancer Cells.

Jamila Djafari,Julia Lorenzo,Javier Fernández-Lodeiro,Hugo M Santos,Emilia Bértolo,Carlos Lodeiro,Sergi Rodriguez-Calado,José Luis Capelo-Martínez

doi:10.3390/ma13235309

Abstract

Non-viral gene delivery using exogenous microRNAs is a potential strategy for fighting cancers with poor prognosis and which lack specific therapies, such as triple-negative breast cancer (TNBC). Herein we report the synthesis of six nontoxic electrostatic polymeric nanocapsules (P1 to P6) for microRNA delivery in TNBC cells. 1H Nuclear Magnetic Resonance (NMR) spectroscopy and Scanning Electron Microscopy (SEM) were used to characterize the nanopolyplexes, synthesized with Poly(L-Lysine) and hyaluronic acid (Ha). Studies on the activity of the ternary HA/PLI/miRNA-34 nanopolyplexes towards TNBC cell line MDA-MB-231 were conducted. The nanopolyplexes mediated intracellular restoration of tumor suppressor miR34a was evaluated by using Western blotting to quantify the expression level of the Bcl-2 protein. The results suggest that the P5, with a ratio PLI/Ha of 0.05, was the most promising for the delivery of miR-34a into TNBC cells; the P5 nanocapsules were able to reduce Bcl-2 expression at a protein level, and had an effect in the overall cell viability after 24 h treatment.

Highlights

Breast cancer is the second leading cause of cancer-related death after lung cancer, and is the most common diagnosed malignancy among women worldwide [1]
The cells treated with a N/P ratio of 20 had little effect in cell inhibition growth, with cell viabilities around 80%. These results suggest that an increasing concentration of imidazole can protect the miRNA-34a delivery by buffering the endosomal medium and facilitating its delivery
The results fortoP2medium and P4 suggest that higher presence of HA in the coating mayfor confer an excessive negative electrostatic charge thein complex

Summary

Introduction

Breast cancer is the second leading cause of cancer-related death after lung cancer, and is the most common diagnosed malignancy among women worldwide [1]. Significant progress has been made in diagnosing, monitoring and treating breast cancer. Non-viral gene delivery using exogenous microRNAs (miRNAs) has emerged as a potential strategy for fighting against cancer. This kind of therapy has gained much attention, especially for Materials 2020, 13, 5309; doi:10.3390/ma13235309 www.mdpi.com/journal/materials. Materials 2020, 13, 5309 more aggressive cancers which have worse prognosis and lack specific therapies, as is the case of the triple-negative breast cancer (TNBC). MiRNAs are conserved non-coding RNAs that negatively regulate gene expression by binding to the complementary sequence in the 30 -untranslated region (UTR)

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Discussion

Conclusion