Enhanced target cell specificity and uptake of lipid nanoparticles using RNA aptamers and peptides

Abstract

Lipid nanoparticles (LNPs) constitute a facile and scalable approach for delivery of payloads to human cells. LNPs are relatively immunologically inert and can be produced in a cost effective and scalable manner. However, targeting and delivery of LNPs across the blood–brain barrier (BBB) has proven challenging. In an effort to target LNPs composed of an ionizable cationic lipid (DLin-MC3-DMA), cholesterol, the phospholipid 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000 (DMG-PEG 2000) to particular cell types, as well as to generate LNPs that can cross the BBB, we developed and assessed two approaches. The first was centered on the BBB-penetrating trans-activator of transcription (Tat) peptide or the peptide T7, and the other on RNA aptamers targeted to glycoprotein gp160 from human immunodeficiency virus (HIV) or C-C chemokine receptor type 5 (CCR5), a HIV-1 coreceptor. We report herein a CCR5-selective RNA aptamer that acts to facilitate entry through a simplified BBB model and that drives the uptake of LNPs into CCR5-expressing cells, while the gp160 aptamer did not. We further observed that the addition of cell-penetrating peptides, Tat and T7, did not increase BBB penetration above the aptamer-loaded LNPs alone. Moreover, we found that these targeted LNPs exhibit low immunogenic and low toxic profiles and that targeted LNPs can traverse the BBB to potentially deliver drugs into the target tissue. This approach highlights the usefulness of aptamer-loaded LNPs to increase target cell specificity and potentially deliverability of central-nervous-system-active RNAi therapeutics across the BBB.

Non-liver mRNA Delivery

“…31−33 The second form of targeting, active targeting, relies on the addition of a targeting moiety to obtain on-target delivery. This includes the use of antibodies, 34,35 aptamers, 36 and other ligands. The ability of LNPs to selectively transfect various cell types within the targeted tissue can be important for potential therapeutic applications, and these conjugations can provide precise control of distribution in an organ.…”

“…Researchers have shown that the delivery vehicle size, composition, charge, and hydrophobicity can impact the type of proteins that bind to nanoparticles in the bloodstream, which in turn impacts their trafficking and uptake. − The second form of targeting, active targeting, relies on the addition of a targeting moiety to obtain on-target delivery. This includes the use of antibodies, , aptamers, and other ligands. The ability of LNPs to selectively transfect various cell types within the targeted tissue can be important for potential therapeutic applications, and these conjugations can provide precise control of distribution in an organ. , However, also changing the molar ratio or the structure of the cholesterol component, the phospholipid, − and the poly­(ethylene glycol) (PEG)-lipid , can affect the tropism of the LNP.…”

Predictive high-throughput screening of PEGylated lipids in oligonucleotide-loaded lipid nanoparticles for neuronal gene silencing

“…16 Preliminary in vitro studies show that pathological genes can be silenced in neurons using LNP-based nucleotide formulations, and ongoing investigations are focused on developing novel LNP compositions that enhance blood–brain barrier penetration to ultimately achieve enhanced in vivo efficacy. 17–20…”

The role of lipid components in lipid nanoparticles for vaccines and gene therapy

“…The nanomedicine field constantly seeks novel organ-targeting compounds. Huge peptide/protein libraries including phage display [121] and bar-coding assays [122] are used to identify strong affinity binders. These and other efforts will hopefully reveal effective active targeting ligands that will advance the LNP targeting capabilities beyond the liver.…”