Functionalized PEG-Lipids for Targeted LNP Nucleic Acid Delivery
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Solution Overview
Problem
Current lipid nanoparticle (LNP) formulations for nucleic acid delivery face challenges such as rapid clearance, off-target tissue uptake, poor efficiency of nucleic acid release into the cytoplasm, and toxicity due to liver accumulation, despite advancements in ionizable cationic lipids.
Innovation Solution
Development of polyethylene glycol (PEG)-lipids and functionalized PEG-lipids that can be conjugated to a binding moiety, forming targeted LNPs (tLNPs) to direct delivery to specific tissues or cell types, with improved conjugation chemistries and symmetrical or asymmetric scaffold structures to enhance biodegradability and targeting specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional LNP formulations are used for nucleic acid delivery, then delivery to liver is achieved, but off-target delivery and toxicity due to liver accumulation occur
Solution Approach 1:
The patent applies local quality by conjugating specific binding moieties (such as antibodies or ligands) to the LNP surface that recognize and bind to receptors on target cells. This creates localized targeting capability where only specific tissues or cell types take up the LNP, rather than uniform distribution to liver, lung, or spleen. The binding moiety provides tissue-specific recognition that directs delivery precisely to the intended target.
Solution Approach 2:
The patent changes key parameters of the LNP formulation including surface charge, particle size, and surface chemistry by incorporating PEG-lipids and conjugating binding moieties. These parameter changes transform the LNP from a liver-targeting formulation to one that can be directed to specific tissues or cell types, reducing off-target accumulation and associated toxicity.
2Reliability
If LNP are administered intravenously, then delivery to liver is maximized, but rapid clearance and liver accumulation toxicity occur
Solution Approach 1:
The patent uses PEG-lipids as an intermediary component on the LNP surface that provides steric stabilization and reduces opsonization by plasma proteins. This intermediary layer extends circulation time by preventing rapid recognition and clearance by the reticuloendothelial system, allowing the LNP to remain in circulation longer and reach target tissues before being cleared.
3Quantity of substance
If current LNP formulations are used, then nucleic acid encapsulation is achieved, but only 2-5% of encapsulated nucleic acid is successfully delivered to cytoplasm
Solution Approach 1:
The patent incorporates ionizable cationic lipids that are neutral at formulation pH but become positively charged in the acidic endosomal environment. This preliminary design allows the LNP to remain stable during circulation and encapsulation, then automatically triggers membrane disruption and nucleic acid release into the cytoplasm upon endosomal acidification, bypassing the need for additional triggers.
Solution Approach 2:
The patent exploits the phase transition of ionizable cationic lipids that occur upon endosomal acidification. The lipids transition from a neutral, membrane-stable state to a charged, membrane-disrupting state, facilitating nucleic acid release from the endosome into the cytoplasm. This phase transition mechanism dramatically improves cytoplasmic delivery efficiency from 2-5% to significantly higher levels.
Data Source
AI summary
Disclosed herein are polyethylene glycol (PEG)-lipids, functionalized PEG-lipids, and functionalized PEG-lipids that are conjugated to a binding moiety which can comprise an antibody antigen binding domain. Also disclosed are methods for synthesizing and functionalizing the PEG-lipids. The PEG-lipids are useful components lipid nanoparticles (LNP) used for the delivery of nucleic acids into living cells, in vivo or ex vivo. LNP comprising functionalized PEG-lipids that are conjugated to a binding moiety are useful as targeted LNP for delivering nucleic acids into cells or tissues expressing the ligand of the binding moiety.