PEG-Modified PLA/PLGA Injectable Gels for Sustained Angiotensin-(1-7) Release
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Solution Overview
Problem
Existing PLA/PLGA-based drug delivery systems suffer from a significant initial burst release of therapeutic cargo, particularly with highly water-soluble drugs, leading to adverse effects and requiring more frequent administration, which compromises patient compliance and comfort.
Innovation Solution
Development of extended-release injectable gel formulations containing angiotensin-(1-7) oligopeptides or variants thereof, combined with biocompatible polymers like PLA or PLGA, designed to minimize initial burst release and provide sustained drug delivery, achieving at least 60% release within 48 hours and maintaining serum concentrations for several days.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PLA/PLGA-based drug delivery systems are used, then biodegradability and tolerability are improved, but initial burst release of therapeutic cargo increases
Solution Approach 1:
The patent modifies the chemical composition parameters of the polymer matrix by incorporating polyethylene glycol (PEG) chains into the PLA/PLGA structure. This parameter change alters the hydrophilicity and degradation characteristics of the polymer, enabling controlled release profiles that minimize initial burst release while maintaining biodegradability and biocompatibility. The PEG content and molecular weight are specifically tuned to achieve the desired release kinetics.
Solution Approach 2:
The patent creates composite polymer materials by combining PLA, PLGA, and PEG in specific ratios to form a novel copolymer system. This composite approach leverages the biodegradability of PLA/PLGA while the PEG component provides hydrophilic channels that control drug diffusion and reduce burst release. The synergistic combination of these polymer components resolves the contradiction between biodegradability and controlled release.
2Reliability
If high water-solubility drugs are used, then therapeutic efficacy is improved, but burst release during initial phase increases
Solution Approach 1:
The PEG-containing polymer acts as an intermediary matrix that mediates between the highly water-soluble drug and the aqueous environment. The PEG chains create a hydrophilic yet structured network that allows controlled hydration and drug release, preventing the drug from rapidly leaching out while maintaining its therapeutic activity. This intermediary polymer structure resolves the conflict between drug solubility and burst release.
Solution Approach 2:
The patent creates a porous or interconnected network structure within the polymer matrix through the PEG components. This porous structure provides controlled pathways for water penetration and drug diffusion, allowing sustained release of highly water-soluble drugs while preventing their immediate release. The porosity and pore size are controlled by the PEG content and molecular weight, enabling fine-tuned release kinetics.
3Stability of the object's composition
If frequent administration is implemented, then sustained drug availability is improved, but patient compliance and comfort deteriorate
Solution Approach 1:
The patent creates a dynamic release system where the polymer matrix progressively degrades and releases drug over an extended period. The degradation rate of the PEG-containing polymer is designed to match the therapeutic requirements, providing sustained drug availability without requiring frequent re-administration. This dynamic, time-dependent release profile improves patient compliance by reducing injection frequency while maintaining therapeutic levels.
Solution Approach 2:
The patent employs a slow, continuous release mechanism that provides just enough drug over an extended period rather than delivering the full dose immediately. This partial release approach, where only a small portion of the total drug is released each day over weeks or months, sustains therapeutic availability while dramatically reducing administration frequency and improving patient comfort and compliance.
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 formulations achieve a controlled release profile with minimal initial burst, ensuring sustained therapeutic levels for extended periods, reducing the frequency of administration and enhancing patient compliance and comfort.
Implementation Method 1
the formulation is configured to have an in vitro release profile including a sustained release of at least 60% of the effective amount of the oligopeptide within 48 hours following placement of the formulation in a release medium
Implementation Method 2
Biodegradable polymers are often leveraged for their ability to be configured into effective controlled-release drug vehicles. In particular, polymer matrices synthesized from polylactic acid (PLA) or poly(lactic co-glycolic acid) (PLGA) chains have been demonstrated to be particularly useful due to their biodegradability and tolerability
Implementation Method 3
wherein the polymer and the oligopeptide are dissolved in an organic solvent
Data Source
AI summary
The present disclosure provides an extended-release gel formulation containing a biocompatible polymer and an angiotensin-(1-7) oligopeptide or a variant thereof. Also provided are methods of treating subjects with vascular dementia, e.g., using the formulations disclosed herein or compositions containing the same, a subject can be administered the extended-release gel formulation to treat the vascular dementia.