Binary Targeting of siRNA to Hematologic Cancer Cells In Vivo Using Layer‐by‐Layer Nanoparticles

Abstract

Using siRNA therapeutics to treat hematologic malignancies has been unsuccessful because blood cancer cells exhibit remarkable resistance to standard transfection methods. Herein, the successful delivery of siRNA therapeutics with a dual-targeted, layer-by-layer nanoparticle (LbL-NP) is reported. The LbL-NP protects siRNA from nucleases in the bloodstream by embedding it within polyelectrolyte layers that coat a polymeric core. The outermost layer consists of hyaluronic acid (a CD44-ligand) covalently conjugated to CD20 antibodies. The CD20/CD44 dual-targeting outer layer provides precise binding to blood cancer cells, followed by receptormediated endocytosis of the LbL-NP. This siRNA delivery platform is used to silence B-cell lymphoma 2 (BCL-2), a pro-survival protein, in vitro and in vivo. The dual-targeting approach significantly enhances internalization of BCL-2 siRNA in lymphoma and leukemia cells, which leads to significant downregulation of BCL-2 expression. Systemic administration of the dual-targeted, siRNA-loaded nanoparticle induces apoptosis and hampers proliferation of blood cancer cells, both in cell culture and in orthotopic non-Hodgkin's lymphoma animal models. These results provide the basis for approaches to targeting blood-borne cancers and other diseases and suggest that LbL nanoassemblies are a promising approach for delivering therapeutic siRNA to hematopoetic cell types that are known to evade transfection by other means.

Nanoparticle-Based Drug Delivery in Cancer Therapy and Its Role in Overcoming Drug Resistance

“…Efflux transporters Bypass efflux transporters NP itself (Murakami et al, 2011) Inhibit efflux transporters COX-2 inhibitors (Zhang S. et al, 2019) P-gp-targeted siRNA (Patil et al, 2010;Navarro et al, 2012) miRNA-495 (He et al, 2019) Apoptosis Inhibit anti-apoptosis pathway Bcl-2-targeted siRNA (Wang et al, 2006;Saad et al, 2008;Chen et al, 2009;Choi et al, 2019) NF-κB inhibitors (pyrrolidine dithiocarbamate/curcumin) (Fan et al, 2010;Misra and Sahoo, 2011;Zhao et al, 2019) Activate pro-apoptosis pathway Ceramide (Devalapally et al, 2007;van Vlerken et al, 2010) p53 gene therapy (Prabha and Labhasetwar, 2004;Choi et al, 2008) Efflux transporters and apoptosis…”

Overcoming Barriers for siRNA Therapeutics: From Bench to Bedside

“…Although the PEI has this capability, one of the major drawbacks is its cytotoxicity, known to increase along with its physical size [ 121 ]. Another reported agent for causing effective endosomal escape is poly(lactic-co-glycolic acid) (PLGA) [ 122 ]. PLGA is a copolymer, biodegradable, biocompatible, and helps in RNAi activity of the siRNA.…”

“…PLGA is a copolymer, biodegradable, biocompatible, and helps in RNAi activity of the siRNA. PLGA provides a sustained release to the siRNA with increased cellular uptake [ 122 ]. Especially, the layer-by-layer complex (nanoparticles) with PEI and PLGA increases the endosomal escape efficiency [ 122 ].…”

“…PLGA provides a sustained release to the siRNA with increased cellular uptake [ 122 ]. Especially, the layer-by-layer complex (nanoparticles) with PEI and PLGA increases the endosomal escape efficiency [ 122 ]. Another strategy for endosomal escape is protonation; two amino acids arginine and lysine get protonated in low pH that lead to destabilizing of cellular membranes.…”

Theranostic Layer‐by‐Layer Nanoparticles for Simultaneous Tumor Detection and Gene Silencing

“…[3] Integrating this biosensor peptide technology into the layer-by-layer (LbL) platform marks as ignificant development towards more sophisticated nanotheranostics.L bL assembly provides an atural route towards multifunctional nanotheranostics by introducing functional nanoscale polymer films onto colloidal substrates that serve to modulate drug release and extend plasma half-life. [4] In addition to easily interchanging the components that comprise the substrate and polyelectrolyte films,t he LbL platform is distinctly capable of incorporating small molecule drugs, [5] therapeutic nucleic acids, [6] imaging modalities, [7] and molecular probes all within ad iscrete NP. [2b, 7, 8] Therefore,t he modularity of this approach also lends itself towards personalizing such NPs to specific clinical contexts.…”