Dextran-Crosslinked ADC Linkers for Stable High DAR Delivery
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Solution Overview
Problem
Current antibody-drug conjugate (ADC) technologies face challenges such as limited drug-to-antibody ratio (DAR), poor colloidal stability, and heterogeneous DAR profiles, leading to reduced efficacy and increased systemic toxicity due to premature linker cleavage in non-target tissues.
Innovation Solution
A dextran-crosslinked nanoparticle (CDex) is developed as a multivalent linker system, allowing precise control over DAR and colloidal stability, with a hydrodynamic diameter of 2 to 20 nm and surface charge modulation, enabling targeted drug delivery and enhanced therapeutic efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ADC linkers are used, then the conjugate can be formed, but the colloidal stability is poor and premature linker cleavage occurs in non-target tissues
Solution Approach 1:
The patent employs a composite linker system combining a small molecule linker with a polysaccharide crosslinked colloidal particle (dextran-CDex). This composite structure provides both the covalent bonding function of the small molecule linker and the colloidal stability of the polysaccharide particle, preventing premature cleavage while maintaining targetability. The dextran-CDex core with surface-exposed reactive groups creates a stable platform that reduces systemic toxicity.
Solution Approach 2:
The patent modifies the physical and chemical parameters of the linker by introducing a crosslinked colloidal particle structure with controlled hydrodynamic diameter (2-20 nm) and surface charge. The crosslinking degree and particle size are optimized to enhance colloidal stability while maintaining appropriate pharmacokinetic properties, thereby preventing premature degradation in non-target tissues.
2Quantity of substance
If the drug-to-antibody ratio (DAR) is increased to improve therapeutic efficacy, then more drugs are delivered, but heterogeneity in DAR profile increases and colloidal stability decreases
Solution Approach 1:
The polysaccharide crosslinked colloidal particle serves as an intermediary carrier between the antibody and the drug payload. Instead of directly conjugating multiple drugs to the antibody (which causes heterogeneity and instability), the drugs are conjugated to the dextran-CDex particle, which then binds to the antibody. This intermediary approach allows high drug loading while maintaining colloidal stability and homogeneous DAR profile.
Solution Approach 2:
The patent segments the ADC into distinct functional modules: the antibody for targeting, the small molecule linker for covalent attachment, and the polysaccharide crosslinked colloidal particle for drug carrier functions. This segmentation allows independent optimization of each component, enabling high drug capacity on the particle while maintaining overall conjugate stability and homogeneous DAR.
3Quantity of substance
If nanoparticles with larger size are used to increase drug capacity, then more drugs can be carried, but the ability to penetrate extracellular matrix and reach tumor cells decreases
Solution Approach 1:
The patent optimizes the hydrodynamic diameter of the polysaccharide crosslinked colloidal particle to a specific range (2-20 nm) that balances drug capacity with tissue penetration ability. This parameter optimization allows the particle to carry sufficient drug load while maintaining the ability to navigate through the extracellular matrix and reach tumor cells effectively, overcoming the trade-off between size and penetration.
Data Source
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AI summary
The present invention relates to a next-generation antibody-drug conjugate (ADC) linker platform technology and to polysaccharide-crosslinked colloidal particle-drug conjugates. More specifically, the invention is characterized by the use of polysaccharide-crosslinked colloidal particles-formed by intramolecular and/or intermolecular crosslinking of 1 to 3 branched polysaccharides or 2 to 30 cyclic polysaccharides at hydroxyl groups of their monosaccharide building blocks using a crosslinker-as a multivalent linker system or drug carrier. For example, the invention includes dextran-crosslinked nanoparticles (CDex), which are formed by intramolecular and/or intermolecular crosslinking of 1 to 3 dextran or dextran derivatives at the hydroxyl groups of glucose building blocks using a crosslinker.