Multi-arm PEG Nanocarriers for High Drug Loading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for drug delivery using polyethylene glycol (PEG) conjugates face challenges in achieving high drug loading with acceptable aqueous solubility and biological characteristics, as existing approaches often result in loss of solubility or require large polymeric carriers that are not biologically suitable.
Innovation Solution
Development of multi-arm polyalkylene oxide nanocarriers, specifically PEG-based, with a high molar ratio of drug to polymer, utilizing disulfide and thioether bonds for crosslinking, and surface modifications to enhance solubility and targeting capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high molecular weight polymeric carriers are used to increase drug loading capacity, then the loading of drugs such as doxorubicin is improved, but the aqueous solubility is lost and the carrier size becomes very large
Solution Approach 1:
The patent uses multi-arm PEG structures (4-arm, 8-arm) where multiple drug molecules are attached to separate arms of the polymer. This segmentation allows high drug loading (multiple copies per carrier) while maintaining the hydrophilic PEG backbone's solubility properties, avoiding the aggregation problems of high molecular weight carriers
Solution Approach 2:
The patent creates composite structures by conjugating drug molecules (such as doxorubicin) to functionalized PEG carriers through specific chemical linkages (thioether, disulfide). This composite approach combines the hydrophilic, soluble PEG backbone with the therapeutic drug molecules, achieving both solubility and high drug loading capacity
2Quantity of substance
If multiple copies of drug are attached to PEG to increase loading, then the drug capacity is improved, but the aqueous solubility is lost
Solution Approach 1:
The patent attaches drugs to specific local sites (terminal groups) of the PEG arms rather than along the entire polymer chain. This localized conjugation maintains the bulk hydrophilic character of the PEG backbone, preserving aqueous solubility even when multiple drug copies are present at the terminal functionalization sites
Solution Approach 2:
The patent employs reversible disulfide bond linkages between the PEG carrier and certain drugs (e.g., doxorubicin). These dynamic bonds can break under reducing conditions (such as intracellular environments), allowing controlled drug release while maintaining carrier solubility and flexibility throughout the circulation process
3Adaptability or versatility
If other agents such as cell adhesion peptides are linked to drugs to improve biological properties, then the targeting capability is improved, but the aqueous solubility is lost
Solution Approach 1:
The patent creates multi-functional PEG carriers that can simultaneously perform multiple functions: the PEG backbone provides solubility and circulation stability, terminal functional groups enable drug conjugation, and additional peptide attachments (such as RGD cell adhesion peptides) provide targeting capabilities. This universal carrier design achieves multiple biological functions without sacrificing aqueous solubility
Solution Approach 2:
The patent extends the functional capabilities of the PEG carrier by adding peptide ligands in a different functional dimension. While the PEG backbone handles solubility, the attached peptides (such as cell adhesion peptides) provide biological recognition and targeting in a separate functional layer, achieving multi-functionality without compromising the solubility-providing PEG structure
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 solution achieves high aqueous solubility and effective drug loading, enabling targeted delivery of anti-inflammatory, anticancer, and HIV Protease Inhibitors, while maintaining biological compatibility and solubility, thus overcoming previous limitations in drug delivery systems.
Implementation Method 1
comprising multi-arm polyalkylene oxide crosslinked via disulfide bonds
Implementation Method 2
comprising multi-arm polyalkylene oxide crosslinked via thioether bonds
Implementation Method 3
wherein the nanogel particles are aggregated via hydrophobic interactions
Data Source
AI summary
Novel classes of multi-arm polyalkylene oxide-based materials including PEG nanocarriers, nanogel particles, and aggregated nanogel particles are disclosed. These classes of compositions may be associated with therapeutic agents and targeting moieties, or visibility enhancing agents, and may have a modified surface structure. In some embodiments the PEG-based materials can be made to provide relatively high drug loads with improved solubility and targeted delivery.