Polymeric Nanoparticles with Tunable Glass Transition for Drug Release

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Solution Overview

Problem

Developing nanoparticle systems that effectively deliver therapeutic agents to specific tissues or cells while minimizing side effects and maintaining stability for controlled release remains a challenge, particularly in cancer treatment where cytotoxic drugs need to target cancer cells without harming surrounding tissues.

Innovation Solution

The method involves preparing nanoparticle suspensions with block copolymers such as poly(D,L-lactic acid) and poly(ethylene glycol) to achieve specific glass transition temperatures, allowing for controlled drug release rates by varying the molecular weights of the polymers, resulting in fast, moderate, or slow release profiles depending on the application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high quantity of therapeutic agent is loaded into nanoparticle, then drug delivery effectiveness is improved, but nanoparticle size becomes too large for practical therapeutic use

Engineering Contradiction:
Improvedrug loadVSAvoidnanoparticle size
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The patent adjusts the glass transition temperature (Tg) of the polymeric matrix as a key parameter to control drug release and loading. By selecting polymers with specific Tg ranges (above or below physiological temperature), the system optimizes both drug loading capacity and nanoparticle size for effective delivery

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses block copolymers comprising hydrophobic segments (for drug loading) and hydrophilic segments (for stability and biocompatibility). This composite structure enables high drug loading while maintaining appropriate nanoparticle size and stability in physiological environments

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If nanoparticle remains stable to limit rapid release, then controlled release is improved, but drug delivery rate may be too slow for effective treatment

Engineering Contradiction:
Improvenanoparticle stabilityVSAvoiddrug release rate
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent exploits changes in the glass transition temperature (Tg) of the polymeric matrix to control drug release kinetics. By selecting polymers with Tg above or below physiological temperature, the system achieves either sustained stable release or rapid release profiles, respectively, allowing optimization for different therapeutic requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates dynamic release profiles by utilizing the temperature-dependent glass transition of the polymer matrix. The nanoparticle system can transition between stable and release states based on temperature conditions, enabling controlled delivery that adapts to physiological conditions

Inventive Principle:
Principle #15Dynamics

3Reliability

If cytotoxic dose is delivered to cancer cells, then treatment efficacy is improved, but surrounding non-cancerous tissue is damaged

Engineering Contradiction:
Improvetreatment efficacyVSAvoidside effects on healthy tissue
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs targeted delivery where nanoparticles accumulate specifically at the tumor site through passive targeting (EPR effect) or active targeting mechanisms. The cytotoxic drug is released locally at the cancer site rather than systemically, maximizing therapeutic efficacy while minimizing exposure and damage to healthy surrounding tissues

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The polymeric nanoparticle acts as an intermediary carrier that protects the cytotoxic drug during circulation and enables controlled release only at the target site. This intermediary system allows delivery of effective cytotoxic doses while reducing direct contact with and damage to healthy tissues

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2515942B1Therapeutic polymeric nanoparticle compositions with high glass transition temperature or high molecular weight copolymers
Publication Date: 2020.02.12 PFIZER INC
  • EP2515942B1 patent drawingFigure 1
  • EP2515942B1 patent drawingFigure 2A
  • EP2515942B1 patent drawingFigure 2B

AI summary

The present disclosure relates in part to pharmaceutical compositions comprising polymeric nanoparticles having certain glass transition temperatures. Other aspects of the invention include methods of making such nanoparticles.