Lipid-Modified G-Quadruplex Oligonucleotides for Fast Micelle Assembly
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Solution Overview
Problem
Tetramolecular G-quadruplexes face issues with slow kinetics of formation and high propensity for undesired conformations due to unfavorable entropy, limiting their practical utility as supramolecular scaffolds.
Innovation Solution
Hybrid Lipid-Oligonucleotides (LONs) are synthesized with a specific lipid moiety at the 5′ or 3′ end, allowing for the formation of stable, long tetramolecular parallel G-quadruplexes through π-π stacking and Hoogsteen hydrogen bonding, which self-assemble into micelles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If G-quadruplexes are formed using long oligonucleotide sequences, then the stability and architectural control of the tetramolecular structure is improved, but the kinetics of formation becomes slower and the propensity for undesired foldings increases
Solution Approach 1:
The invention applies preliminary action by pre-organizing the oligonucleotide strands into a spatially defined complex where the four strands are covalently attached to a cyclic template. This pre-organization converts the unfavorable quaternary complex formation into a more favorable first-order process, dramatically accelerating kinetics while maintaining long sequence stability
Solution Approach 2:
The invention uses a cyclic template as an intermediary structure that mediates the assembly of four oligonucleotide strands. The template serves as a scaffold that brings the strands into correct spatial arrangement, facilitating rapid and specific tetramolecular G-quadruplex formation without undesired foldings
2Stability of the object's composition
If G-quadruplexes are formed using long oligonucleotide sequences, then the architectural control is improved, but the conformational diversity and undesired foldings increase
Solution Approach 1:
The cyclic template pre-organizes the four oligonucleotide strands in a defined spatial arrangement before G-quadruplex formation. This preliminary structuring ensures that only the desired parallel tetramolecular conformation can form, eliminating polymorphism and undesired foldings even with long sequences
Solution Approach 2:
The cyclic template acts as an intermediary scaffold that enforces a unique geometric arrangement of the four strands. This template-mediated assembly ensures high conformational purity by preventing alternative foldings while maintaining the desired parallel G-quadruplex architecture
3Speed
If a cyclic template with covalently attached strands is used, then the kinetics of formation is improved, but the device complexity and synthetic difficulty increase
Solution Approach 1:
The invention segments the complex assembly process into two simpler steps: first, synthesizing individual oligonucleotide strands with template-binding sequences; second, allowing spontaneous assembly on the cyclic template. This segmentation avoids the need for complex multi-step covalent attachment while achieving rapid formation kinetics
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 modified oligonucleotides form stable micelles with rapid kinetics and controlled architecture, suitable for therapeutic and technological applications, including drug delivery and nanotechnology devices.
Implementation Method 1
stabilized by π-π stacking between G-quartets (G4)
Implementation Method 2
stabilized by π-π stacking between G-quartets (G4) and via Hoogsteen hydrogen bonding
Implementation Method 3
Their amphiphilic nature impart them with self-assembling properties and LONs were found to come in a diversity of different supramolecular structures
Data Source
AI summary
The present invention relates to tetramolecular parallel G-quadruplex-forming oligonucleotides. If G-quadruplexes are of prime importance in biology, their use is hampered by the propensity of G4-prone DNA molecules, in particular G4-prone DNA molecules of long size, to adopt many different G4 topological conformations or other alternative foldings. By introducing a lipid modification at the end of the oligonucleotide, the inventors succeeded in obtaining long tetramolecular parallel G-quadruplexes (tp G4). The present invention thus concerns an oligonucleotide modified by substitution at the 5′ or the 3′ end by a lipid moiety, wherein said oligonucleotide comprises a nucleic acid sequence of at least 10 nucleotides, said nucleic acid sequence including a series of at least 4 consecutive guanine residues located at the 5′ or 3′ end of said sequence. A tetramolecular parallel G-quadruplex comprising 4 identical modified oligonucleotides as defined above, wherein each of the 4 consecutive guanine residues included at the 5′ or 3′ end of the nucleic acid sequence of each oligonucleotide respectively form G-quartets with the corresponding guanine residues of the other 3 oligonucleotides, said G-quartets being stabilized by π-π staking and Hoogsteen hydrogen bonding, is also contemplated.