Multivalent Oligonucleotide Complexes for Sustained Gene Silencing
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Solution Overview
Problem
Current antisense and RNAi technologies face challenges such as short-term effectiveness, toxicity, stability issues, and off-target effects in gene silencing, particularly in achieving multivalent inhibition of gene expression in higher vertebrates.
Innovation Solution
Development of precisely structured oligonucleotide complexes comprising multiple self-complementary regions that target multiple sites within a single gene or across different genes, eliminating the need for additional non-targeting strands and enhancing specificity and potency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional siRNA or antisense oligonucleotides are used for gene silencing, then gene inhibition can be achieved, but the effectiveness is short-term and toxicity occurs at required doses
Solution Approach 1:
The patent combines multiple siRNA molecules into a single multivalent oligonucleotide by linking them through self-complementary regions. This merging approach concentrates multiple gene-silencing functions into one molecule, achieving sustained effectiveness without requiring multiple separate administrations that would increase cumulative toxicity
Solution Approach 2:
The self-complementary regions enable the oligonucleotide to maintain its structure and function over extended periods. The continuous gene silencing action is achieved through the stable formation of RNA interference complexes that persist longer than conventional siRNA, reducing the need for repeated dosing and associated toxicity
2Stability of the object's composition
If chemical modifications are made to siRNA to improve stability, then nuclease sensitivity is reduced, but the cost increases and additional synthesis steps are required
Solution Approach 1:
The oligonucleotide design incorporates self-complementary regions that automatically form stable secondary structures without requiring external chemical modifications. The molecule self-organizes into stable configurations through intrinsic base-pairing, eliminating the need for expensive chemical stabilization while maintaining nuclease resistance
Solution Approach 2:
The patent changes the structural parameters of the oligonucleotide by introducing self-complementary sequences that form hairpin or stem-loop structures. These structural changes inherently increase stability against nucleases without requiring chemical backbone modifications, simplifying synthesis while maintaining stability
3Measurement precision
If single siRNA duplexes are used for gene targeting, then specificity to a single gene is achieved, but off-target effects on secondary genes occur
Solution Approach 1:
The patent merges multiple siRNA targeting sequences into a single multivalent oligonucleotide structure. Each siRNA component targets a different gene or different sites within the same gene, allowing simultaneous specific inhibition of multiple targets while using one administered molecule, thereby reducing off-target effects through coordinated action
Solution Approach 2:
The multivalent oligonucleotide serves multiple functions within a single molecule: it can target multiple different genes simultaneously, or multiple sites within a single gene, or provide both therapeutic and diagnostic functions. This multi-functionality increases precision by addressing multiple targets with one agent rather than using separate agents that could cause off-target effects
4Stability of the object's composition
If non-naturally occurring nucleotides and modifications are incorporated, then antisense stability is improved, but in vivo expression capability is lost requiring external synthesis and administration
Solution Approach 1:
The patent changes the nucleotide composition parameters by using only naturally occurring nucleotides in the oligonucleotide design. This allows the molecule to be transcribed from DNA templates in vivo using cellular RNA polymerases, providing adaptability for in vivo expression while achieving stability through the self-complementary structural design rather than chemical modifications
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves sustained and targeted gene inhibition with increased potency and specificity, reducing off-target effects and enabling multivalent gene regulation.
Implementation Method 1
antisense nucleic acids (NA) base pair with a target RNA resulting in inactivation of the targeted RNA. Target RNA recognition by antisense RNA or DNA can be considered a hybridization reaction
Implementation Method 2
The long RNA duplex and the shRNA duplex are pre-cursors that are processed into small interfering RNA (siRNA) by the endoribonuclease described as Dicer
Implementation Method 3
The processed siRNA or directly introduced siRNA is believed to join the protein complex RISC for guidance to a complementary gene, which is cleaved by the RISC/siRNA complex
Data Source
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AI summary
The present invention includes bivalent or multivalent nucleic acid molecules or complexes of nucleic acid molecules having two or more target-specific regions, in which the target-specific regions are complementary to a single target gene at more than one distinct nucleotide site, and/or in which the target regions are complementary to more than one target gene or target sequence. Also included are compositions comprising such nucleic acid molecules and methods of using the same for multivalent RNA interference and the treatment of a variety of diseases and infections.