Polymeric Cascade Prodrug with Self-Immolative Linker
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Solution Overview
Problem
Current polymer-based drug delivery systems face challenges such as uncontrolled drug release, functional inactivation of therapeutics like proteins and peptides, and interpatient variability due to enzymatic dependence, which limits the effectiveness and predictability of drug release profiles.
Innovation Solution
Development of polymeric cascade prodrugs with a masking group containing a nucleophile, distinct from the carrier, that undergoes a 1,(4+2p) elimination reaction for controlled drug release, utilizing a two-step mechanism involving intramolecular catalysis or cyclization for non-enzymatic cleavage, ensuring stable and predictable drug release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If non-covalent drug encapsulation is used, then long-acting release profiles are achieved, but uncontrolled burst-type release and functional inactivation of therapeutics occur
Solution Approach 1:
The invention divides the drug release process into two distinct stages: a lag phase where the drug is retained within the polymer matrix, and a subsequent release phase. This segmentation is achieved through the specific polymer composition and drug-polymer interaction mechanisms, creating a predictable temporal profile that avoids burst release while maintaining prolonged action.
Solution Approach 2:
The polymer matrix acts as an intermediary between the drug and the external environment. Through specific polymer-drug interactions and controlled polymer degradation, the matrix mediates the release process, providing both retention during storage and controlled release upon administration, thereby resolving the contradiction between prolonged duration and reliable control.
2Duration of action of stationary object
If non-covalent drug encapsulation is used, then depot formulations are created, but functional inactivation of proteins and peptides occurs during encapsulation and storage
Solution Approach 1:
The invention creates different local environments within the polymer matrix: hydrophobic regions for drug retention and hydrophilic channels for drug release. This local quality differentiation allows the drug to be protected from inactivation during storage while enabling functional release upon administration, resolving the contradiction between prolonged duration and therapeutic functionality.
Solution Approach 2:
The polymer matrix undergoes parameter changes during the release process, transitioning from a drug-retentive state to a drug-release state. This includes changes in polymer conformation, hydrophilicity, and degradation state, which allow the system to maintain drug functionality during storage while enabling controlled release when needed.
3Quantity of substance
If covalent conjugation of drug to polymer is used, then solubility of small molecule compounds is improved, but biological activity of the drug is reduced or lost
Solution Approach 1:
The polymer is prepared in advance with specific functional groups and structural characteristics that enable reversible drug binding. This preliminary preparation allows the polymer to solubilize the drug during storage while maintaining the drug's biological activity, and to release the active drug upon administration through controlled degradation or conformational changes.
Solution Approach 2:
The drug-polymer complex is designed to be dynamic rather than static, allowing reversible association and dissociation. The polymer structure can change conformation and the drug can bind and unbind dynamically, enabling the system to maintain solubility during storage while preserving and releasing biological activity when needed, resolving the contradiction between solubility enhancement and activity retention.
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 enables controlled and predictable release of biologically active molecules with reduced interpatient variability and minimized side reactions, maintaining the integrity of therapeutic agents and improving drug delivery efficacy.
Implementation Method 1
utilizing a two-step mechanism involving intramolecular catalysis or cyclization for non-enzymatic cleavage
Implementation Method 2
involving intramolecular catalysis or cyclization for non-enzymatic cleavage
Implementation Method 3
masking group containing a nucleophile, distinct from the carrier, that undergoes a 1,(4+2p) elimination reaction for controlled drug release
Implementation Method 4
One way to solubilize these small molecule compounds is to conjugate them to hydrophilic polymers
Implementation Method 5
The passive targeting of polymeric drug conjugates to tumors is based on the so-called enhanced permeability and retention effect (EPR)
Implementation Method 6
Release of the drug occurs when the polymer swells or degradation of the polymer allows for diffusion of the drug to the exterior. Such degradation processes may be autohydrolytic or enzyme-catalyzed
Implementation Method 7
So-called PEGylated proteins have shown improved therapeutic efficacy by increasing solubility, reducing immunogenicity, and increasing circulation half-live in vivo due to reduced renal clearance and proteolysis by enzymes
Data Source
AI summary
A cascade carrier linked prodrug is described which comprises a biologically active moiety and a masking group having at least one nucleophile and being distinct from the carrier.