Lipophilic Nucleotide Conjugates for Extrahepatic siRNA Uptake
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Solution Overview
Problem
Current methods for delivering small interfering RNA (siRNA) to extrahepatic tissues face challenges in enhancing in-vivo delivery efficiency, limiting its therapeutic application.
Innovation Solution
A lipophilic nucleotide analogue is synthesized with specific structural components, including a hydroxyl protecting group, lipophilic group, and nucleotide base, to enhance siRNA delivery efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lipophilic conjugates are added to enhance siRNA delivery to extrahepatic tissues, then cellular uptake is improved, but delivery efficiency to target tissues remains insufficient
Solution Approach 1:
The patent modifies the chemical structure of nucleotide analogues by changing parameters such as sugar ring configuration (2'-O-methyl, 2'-fluoro modifications), phosphate backbone composition (phosphorothioate linkages), and conjugating different lipophilic moieties (cholesterol, galactosyl-cholesterol) to optimize both cellular uptake and tissue-specific delivery efficiency
Solution Approach 2:
The invention creates composite structures by conjugating lipophilic groups (cholesterol, GalNAc) with nucleotide backbones to form hybrid molecules that combine the benefits of nucleic acid specificity with lipid membrane permeability and tissue-targeting capabilities, achieving enhanced delivery to extrahepatic tissues
2Reliability
If current delivery strategies (lipid nanoparticles, GalNAc conjugates) are used, then some delivery improvement is achieved, but in-vivo delivery efficiency to extrahepatic tissues is still limited
Solution Approach 1:
The patent introduces tissue-specific targeting by incorporating galactosyl-cholesterol conjugates that specifically target asialoglycoprotein receptors on hepatocytes and extrahepatic tissues, providing localized delivery enhancement at target sites while maintaining systemic circulation properties
Solution Approach 2:
The invention employs dynamic optimization of delivery systems by creating a library of nucleotide analogues with varying lipophilic modifications (different chain lengths, different conjugation positions) to adapt to different tissue targets and delivery conditions, maximizing therapeutic potential across multiple indications
Data Source
AI summary
A lipophilic nucleotide analogue of the following formula:where Y is a hydroxyl protecting group, R1 is a C1-6 alkyl or a halogen-substituted C1-6 alkyl, R2 is a C1-6 alkyl or a halogen-substituted C1-6 alkyl, L is a lipophilic group; and Base is a nucleotide base. A preparation of the nucleotide analogue fromis provided. A method for enhancing the in-vivo delivery of nucleic acid drugs with the nucleotide analogue is also provided.