Segmented Polymer Micelle for Targeted Drug Delivery
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Solution Overview
Problem
Conventional active targeting drug delivery systems (DDS) fail to adequately reduce adverse side effects and ensure sufficient drug concentration at focal sites, as drugs are not effectively targeted and can expose normal cells to the drug, leading to unwanted damage.
Innovation Solution
An active targeting polymer micelle is designed with separate backbone polymer units, one containing a target binding site and the other a drug, arranged radially to facilitate specific binding and uptake by target cells, while ensuring the drug is released inside the cell and the non-bound polymer unit is metabolized if not taken up, preventing exposure to normal cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a drug and ligand are bound to one synthetic polymer chain in conventional active targeting DDS, then the drug can be directed to target cells, but the drug remains continuously exposed to blood when not taken up, causing adverse side effects
Solution Approach 1:
The patent divides the polymer conjugate into two separate chains: one carrying the ligand for target binding and another carrying the drug. This segmentation allows the drug to be isolated from the circulation until internalized by the target cell, eliminating continuous blood exposure and adverse side effects while maintaining targeting accuracy through the ligand-bearing polymer chain.
2Reliability
If molecular target drugs are developed with specific binding ability to molecular markers, then therapeutic specificity is improved, but adverse side effects such as interstitial pneumonitis still occur and therapeutic effect at focal site is insufficient
Solution Approach 1:
The patent introduces a polymer conjugate as an intermediary carrier system. The ligand-bearing polymer chain acts as a mediator that first binds to target cells through specific molecular recognition, then facilitates internalization and releases the drug inside the cell. This intermediary mechanism ensures the drug is delivered only to target cells, preventing adverse side effects while maintaining therapeutic specificity.
3Reliability
If a polymer conjugate is bound to a corresponding receptor but not taken up into a cell, then targeting is achieved, but the drug is continuously exposed to blood causing potential damage to normal cells
Solution Approach 1:
By separating the ligand and drug onto different polymer chains, the patent ensures that when the ligand-bound polymer binds to the target receptor, the drug remains isolated on the other chain. Only after internalization does the drug become accessible, preventing continuous blood exposure and harm to normal cells while maintaining effective target binding.
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
This approach significantly reduces adverse side effects by ensuring the drug is delivered specifically to target cells and metabolized if not taken up, maintaining optimal drug concentration and minimizing harm to normal cells.
Implementation Method 1
when the micelle is bound to a target while maintaining the radial arrangement, the micelle is taken up into a cell supplying the target through endocytosis
Implementation Method 2
the drug is released into the cell by collapse of the radial arrangement in the cell
Implementation Method 3
when the radial arrangement collapses in blood before the micelle is bound to a target, the backbone polymer unit β is excreted through metabolism
Data Source
AI summary
The present invention provides an active targeting polymer micelle encapsulating a drug, preventing an inappropriate release of a drug which may damage a normal cell. A polymer micelle 100 includes a backbone polymer unit 10 that has a target binding site 11 and a backbone polymer unit 20 that has a drug 14 and is free from the target binding site 11, such polymer units 10 and 20 being disposed in a radial arrangement in a state where the target binding site 11 is directed outward and the drug 14 is directed inward, in which: i) when the micelle is bound to a target 40 while maintaining the radial arrangement, the micelle is taken up into a cell 50 supplying the target 40 through endocytosis, and the drug 14 is released into the cell 50 by collapse of the radial arrangement in the cell 50; and ii) when the radial arrangement collapses in blood 60 before the micelle is bound to a target 40, the unit 20 is excreted through metabolism, to thereby prevent a normal cell from being damaged by the drug 14.