Co-delivery of RNAi and chemokine by polyarginine nanocapsules enables the modulation of myeloid-derived suppressor cells

Abstract

Myeloid-Derived Suppressor Cells (MDSCs), immunosuppressive cells that promote tumor growth, represent an attractive target in cancer immunotherapy. However, the clinical success of this strategy is limited by the lack of efficient drug delivery vehicles targeting this cell compartment. The objective of this work was to develop a delivery carrier, multilayer polymer nanocapsules, with the capacity to co-encapsulate two types of immunomodulatory drugs, a chemokine and an RNAi sequence, aimed at reverting MDSC-mediated immunosuppression. The chemokine CCL2, intended to attract monocyte-macrophage MDSCs, was encapsulated within the L2 inverse micellar aqueous domains of the lipid core of these nanocapsules. On the other hand, two different RNAi sequences that modulate the CCAAT/enhancer-binding protein beta (C/EBPβ) pathway, shC/EBPβ and miR 142-3p, were successfully associated to their polymer shell. These RNAi sequences were covered by subsequent layers of polyarginine and hyaluronic acid, thereby creating multi-layered assemblies that protected them and facilitated their targeted delivery. The in vitro studies performed in primary MDSCs cultures showed the capacity of miR 142-3p-loaded nanocapsules to reduce the highly immunosuppressive monocytemacrophage subset. Additionally, the encapsulation of CCL2 within the nanocapsules induced a potent monocyte-macrophage chemoattraction that could be used to direct the therapy to these cell subsets. Finally, in vitro and in vivo studies showed the capacity of shC/EBPβ-loaded nanocapsules to downregulate C/EBPβ levels in MDSCs and to reduce monocyte differentiation into tumor-associated macrophages in an MCA-203 fibrosarcoma mice model. In conclusion, the multilayer polymer nanocapsules described here are efficient vehicles for the co-delivery of proteins and RNA, and are potential candidates as nanomedicines for the modulation of MDSCs.

Polymeric Nanocapsules as Nanotechnological Alternative for Drug Delivery System: Current Status, Challenges and Opportunities

“…Ledo et al developed a multilayer polymeric nanocapsule, with the ability to co-encapsulate a chemokine and an RNAi sequence for immunotherapy. The chemokine was entrapped in the lipid core, while, RNAi sequence was covered by subsequent layers of polyarginine and hyaluronic acid [120]. By possible arrangement of the layer order, the nanocapsules formulated by LBL methods can achieve diverse drug release behavior in different pH environment.…”

Arginine-Based Poly(I:C)-Loaded Nanocomplexes for the Polarization of Macrophages Toward M1-Antitumoral Effectors

“…been explored. Based on the known capacity of cell penetrating peptides (CPPs) to efficiently condense nucleic acids and facilitate their transport across biological barriers (37), we have developed polyarginine-(pArg) and protamine-based nanosystems, which have shown the capacity to efficiently deliver different polynucleotides (38)(39)(40). Indeed, we have recently reported the formation of nanocomplexes of polynucleotides with cationic molecules, and their posterior envelopment with an hydrophilic anionic polymer, named as enveloped nanocomplexes (ENCPs), as a way to facilitate the delivery of miRNA to the brain (40).…”

Targeting of immunosuppressive myeloid cells from glioblastoma patients by modulation of size and surface charge of lipid nanocapsules

“…Moreover, Zinc-doped iron oxide nanoparticles modified with polyethylenimine molecules and dimercaptosuccinic acid in combination with radiotherapy prolonged survival of CT-2A mouse glioma model and were mainly incorporated by TAM/MDSCs, although the definition of these cell populations was based only on CD45 and CD11b markers without further characterization [34]. The activity of MDSCs was shown to be modulated also using polyarginine nanocapsules carrying the chemokine CCL2 and an RNAi sequence targeting C/EBPβ, a transcriptional factor fundamental for MDSC differentiation and functions [35], thus showing that MDSCs represent an interesting target in a nanomedicine approach.…”