Nucleolin Aptamer Affinity via 5-Position Hydrophobic Modification
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Solution Overview
Problem
Current aptamers targeting nucleolin for cancer diagnosis and treatment have limitations in affinity and stability, particularly in binding to cancer cells, due to structural modifications that affect their properties and functionality.
Innovation Solution
Development of chemically modified deoxyuridine-containing GRO29A and AS1411 aptamers with hydrophobic groups at the 5-position, such as benzylcarboxamide, naphthylcarboxamide, or pyrrolebenzylcarboxamide, which enhance their affinity to nucleolin by modifying thymidines in specific positions, forming more stable G-quadruplex structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical modifications are made on the ribose backbone of aptamer nucleotides using 2'-amino or 2'-fluoro pyrimidines to increase nuclease resistance and membrane transfer capability, then stability and membrane penetration are improved, but the structure of aptamers is influenced, resulting in loss of aptamer properties
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of deoxyuridine at the 5-position with hydrophobic groups (benzyl, naphthyl, or 4-pyrrolebenzyl carboxamide). This specific chemical parameter modification enhances nuclease resistance and membrane transfer capability while preserving the aptamer's binding properties to nucleolin, resolving the contradiction between stability improvement and structural integrity maintenance
2Ease of operation
If chemical modifications are made to enhance membrane transfer capability and nuclease resistance, then stability and penetration are improved, but specific binding to target is reduced
Solution Approach 1:
The patent applies local quality by introducing hydrophobic groups specifically at the 5-position of deoxyuridine residues, rather than modifying the entire aptamer structure. This localized modification at specific positions enhances membrane penetration and nuclease resistance while maintaining the overall structural framework and specific binding capability of the aptamer to nucleolin
3Ease of manufacture
If standard aptamers are used for cancer targeting, then production is inexpensive and rapid, but affinity to cancer cells is limited
Solution Approach 1:
The patent applies parameter changes by modifying the chemical parameters of the aptamer structure through 5-position deoxyuridine substitution with hydrophobic groups. This enhancement of binding affinity is achieved through chemical parameter optimization rather than through time-consuming SELEX procedures, maintaining the advantage of inexpensive and rapid production while significantly improving cancer cell targeting affinity
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 aptamers demonstrate significantly increased targeting affinity and binding to various cancer cell lines, improving their diagnostic and therapeutic potential without the need for additional SELEX procedures, and exhibit enhanced stability and specificity.
Implementation Method 1
one or more thymidines (T) are independently substituted with a modified deoxyuridine (dU), and wherein the modified dU is a deoxyuridine having a hydrophobic group at 5 position
Data Source
AI summary
Improved G-rich oligonucleotide (GRO) aptamers specific to nucleolin, a method of preparing the aptamers, and a use of the aptamers for diagnosing and/or treating a nucleolin-associated disease, are provided.