Biodegradable Polymer Drug Conjugates Controlled Release
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Solution Overview
Problem
Existing polymer-bioactive moiety conjugates face challenges in controlled drug release due to dependence on polymer breakdown, leading to uncontrolled dosages and limited drug loading, as well as steric and thermodynamic constraints affecting bioactive moiety distribution and release.
Innovation Solution
Development of biodegradable polymers with releasable bioactive moieties pendant from the polymer backbone, formed from monomeric units coupled via biodegradable moieties, allowing for controlled release of bioactive moieties at a rate equal to or faster than polymer biodegradation, maintaining structural integrity and achieving higher drug loading (>10% by weight).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the admixture approach is used to prepare polymer-drug formulations, then the drug release is dependent on polymer breakdown, but this results in poor control of drug release rate and uncontrolled dosages
Solution Approach 1:
The patent extracts the drug release mechanism from the polymer degradation process. By covalently linking the drug to the polymer backbone through a cleavable bond, the drug can be released through bond cleavage while the polymer backbone remains intact and maintains its structural function, thereby achieving controlled drug release without requiring complete polymer breakdown.
Solution Approach 2:
The patent segments the drug-polymer system into distinct functional components: the polymer backbone provides structural integrity and mechanical support, while the covalently attached drug moiety provides therapeutic function. The cleavable bond between them allows independent control of drug release from the polymer structure, enabling precise dosage control.
2Reliability
If covalent linking of drug molecules to pre-formed polymer backbone is used, then drug-polymer conjugates are formed, but steric and thermodynamic constraints affect bioactive moiety distribution and reduce control over release
Solution Approach 1:
The patent applies local quality by designing specific cleavable bond linkages at the drug-polymer interface that are chemically distinct from the polymer backbone. These localized cleavable bonds (such as ester, amide, or disulfide bonds) provide controlled release functionality at specific sites without affecting the overall polymer structure, thereby overcoming steric constraints and improving release control.
3Reliability
If the polymer structure must degrade to release the drug, then drug release is achieved, but the polymer structure cannot be maintained during drug release
Solution Approach 1:
The patent extracts the drug release function from the polymer degradation process by using covalent bonds with cleavable linkages. This allows the drug to be released through bond cleavage while the polymer backbone remains intact, maintaining structural integrity and mechanical properties throughout the drug release period.
Solution Approach 2:
The patent incorporates cleavable bonds into the polymer-drug conjugate during synthesis, preparing the system in advance for controlled drug release. These pre-installed cleavable linkages are designed to break under specific physiological conditions (such as enzymatic degradation or pH changes), enabling triggered drug release without compromising the polymer structure.
4Quantity of substance
If the amount of drug loaded into admixture is increased, then higher drug loading is achieved, but the control over release rate is further compromised
Solution Approach 1:
The patent changes the fundamental parameter of drug-polymer interaction from physical mixing to covalent bonding. This allows the drug loading amount to be precisely controlled at the molecular level during polymer synthesis, and the release rate to be controlled by the chemistry of the cleavable bond, achieving both high drug loading and precise release control simultaneously.
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 biodegradable polymers enable controlled and efficient delivery of bioactive moieties while maintaining polymer structural integrity, achieving substantial bioactive moiety release before significant polymer breakdown, with the polymer degrading into non-toxic residues.
Implementation Method 1
the biodegradable polymer backbone is formed from monomeric units that are each coupled via a biodegradable moiety
Data Source
AI summary
The invention relates to a biodegradable polymer comprising a plurality of releasable bioactive moieties, the releasable bioactive moieties being pendant from and covalently bonded to the biodegradable polymer backbone, wherein the biodegradable polymer backbone is formed from monomeric units that are each coupled via a biodegradable moiety, and wherein the bioactive moieties are capable of being released at a rate equal to or faster than the rate of biodegradation of the polymer backbone.