Segmented Degradable Polymers for Renal Clearance
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Solution Overview
Problem
There is a need for multiarm polymer derivatives that offer a high molecular weight for extended in vivo circulation time while ensuring timely clearance from the body, as existing branched polymer structures can be inefficient in renal elimination.
Innovation Solution
The development of segmented, degradable polymeric reagents with multiarm configurations and cleavable linkages, allowing for the formation of conjugates with a high total polymer number average molecular weight suitable for renal clearance, where each polymer segment has a molecular weight less than 20,000 Da, enabling efficient elimination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If high molecular weight polymers are used to extend in vivo circulation time, then circulation time is improved, but renal clearance efficiency deteriorates
Solution Approach 1:
The polymer is divided into multiple segments connected by degradable linkages. Each segment has a molecular weight below the renal clearance threshold (20,000 Da), but when assembled together form a high molecular weight polymer that provides extended circulation time. The degradable linkages allow the polymer to be cleaved into smaller segments for renal elimination after performing its function.
2Quantity of substance
If long poly(ethylene glycol) chains are attached to active agents to increase water solubility, then water solubility is improved, but pharmacologic activity deteriorates
Solution Approach 1:
The long poly(ethylene glycol) chain is segmented into multiple shorter chains connected by degradable linkages. Each segment provides sufficient hydrophilicity for water solubility while being short enough to avoid wrapping around and blocking the active agent's ligands. The segmented structure reduces the steric hindrance to ligand access while maintaining solubility benefits.
3Duration of action of moving object
If branched polymer structures are used to increase circulation time, then circulation time is improved, but in vivo clearance deteriorates
Solution Approach 1:
The branched polymer structure incorporates degradable linkages at the branch points and along the arms. This segmentation allows the branched architecture to provide extended circulation time through its high molecular weight configuration, while simultaneously enabling enzymatic or chemical cleavage into smaller, clearable fragments for renal elimination.
Solution Approach 2:
The polymer structure transitions from a static high molecular weight branched structure to dynamic segments through degradable linkages. These linkages can be cleaved in response to physiological conditions (pH, enzymes, redox potential), allowing the polymer to dynamically change from an intact circulation-extended form to degraded clearance-optimized fragments.
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 allows for prolonged circulation time of therapeutic agents while ensuring complete renal clearance, addressing the limitations of existing polymer structures by incorporating degradable linkages that facilitate timely elimination of the polymer from the body.
Implementation Method 1
characterized by one or more degradable linkages. Upon administration, a conjugate described herein degrades at one or more degradable linkages to thereby result in smaller species that can be eliminated more efficiently
Data Source
AI summary
The present invention provides, among other things, segmented, degradable polymeric reagents suitable for reaction with biologically active agents to form conjugates, the polymeric reagents comprising one or more polymer chains divided or separated by one or more degradable linkages into polymer segments having a molecular weight suitable for renal clearance. The polymeric reagents can have a substantially linear structure, a branched structure, or a multiarm structure. Each structure includes one or more linkages capable of degradation in vivo.