Cationic Mucic Acid Polymer Nanoparticles for siRNA Delivery
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Solution Overview
Problem
Current siRNA delivery systems face challenges with short circulation time and excessive non-siRNA components, leading to adverse reactions and inefficient delivery of nucleic acids in vivo.
Innovation Solution
Development of cationic mucic acid-based polymers, such as cMAP, which form diblock and triblock copolymers with polyethylene glycol, enabling the formation of nanoparticles that stabilize siRNA and maintain it in circulation longer by reducing excess cationic components and using boronic acid linkages for PEGylation and targeting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If cationic polymers are used to deliver siRNA, then siRNA delivery to target is achieved, but circulation time is limited due to fast clearance
Solution Approach 1:
The patent modifies the polymer structure by incorporating PEG chains of specific molecular weights (500-50,000 Da) to alter the hydrodynamic radius and surface properties of the nanoparticle, thereby extending circulation time while preserving siRNA delivery capability through optimized cationic segment composition
Solution Approach 2:
The patent creates composite polymer structures combining cationic segments (for siRNA complexation) with PEG segments (for circulation extension), forming amphiphilic copolymers that simultaneously achieve stable siRNA binding and prolonged blood circulation through the synergistic interaction of hydrophobic and hydrophilic domains
2Reliability
If excess cationic components are included in the formulation, then siRNA complexation is enhanced, but adverse reactions increase
Solution Approach 1:
The patent distributes cationic charges locally within specific segments of the copolymer rather than uniformly throughout the entire polymer chain, allowing sufficient siRNA complexation at the local interface while the PEG segments provide a neutral, biocompatible exterior that minimizes systemic adverse reactions
Solution Approach 2:
The patent optimizes the charge ratio and molecular weight parameters of the cationic segments to achieve minimal effective dosing, where the cationic portions are sufficient for stable siRNA complexation but minimized in quantity to reduce toxicity and adverse immunogenic responses
3Duration of action of moving object
If PEGylation is performed using boronic acid linkages, then circulation time is prolonged, but formulation complexity increases
Solution Approach 1:
The patent combines the PEGylation function and the structural backbone into a single copolymer molecule, where PEG segments are covalently integrated into the polymer chain rather than being added as separate surface modifiers, thereby simplifying the overall formulation process while achieving prolonged circulation
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 cMAP-based nanoparticles demonstrate prolonged circulation times and improved bioavailability of siRNA, reducing adverse reactions and enhancing the delivery efficiency of siRNA by forming stable, monodispersed particles with reduced excess polymer content.
Implementation Method 1
CALAA-01 contains a cyclodextrin-based polycation (CDP) that assembles with siRNA via electrostatic interactions between positive charges on the polymer and negative charges on the siRNA backbone
Implementation Method 2
the polymer and the second boronic acid-containing polymer are reversibly connected to one another by a borate condensation linkage between the boronic acid moieties of Formula (X) and at least one pair of vicinal diols of the polyhydroxy linkages
Data Source
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AI summary
The present disclosure is directed to polymer and polymer conjugate-based nanoparticle delivery systems for delivering biological agents, and methods of making and using these compositions. Certain embodiments of the present disclosure provide a nanoparticle comprising a polymer comprising alternating charged and uncharged segments comprising one or more of the following structural units of Formula (I), Formula (II) or Formula (III): wherein A is an uncharged segment comprising polyalkylene glycol; and B is a cationically charged segment comprising at least one polyhydroxy linkage comprising at least one pair of vicinal diols.