Stimuli-Responsive Microparticles for Controlled Active Agent Release

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Solution Overview

Problem

Existing encapsulation methods are inflexible in controlling the release of active agents, often releasing in response to a single stimulus, which limits their application in various industries where controlled or triggered release is necessary, especially for chemically unstable odorants or agents exposed to external stresses.

Innovation Solution

Polymeric-enveloped microparticles comprising HASE type acrylic copolymers, solid-liquid phase change materials, and active agents that can release in response to pH changes, temperature variations, or mechanical stress, allowing for controlled and triggered release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional encapsulation methods are used, then active agents can be protected from external environment, but the release control is inflexible and limited to single stimulus response

Engineering Contradiction:

Improveprotection of active agentVSAvoidrelease control flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The encapsulation system incorporates multiple stimuli-responsive components (pH-sensitive polymers, temperature-sensitive lipids, oxidation-sensitive disulfide bonds) within a single capsule structure, enabling the same capsule to respond to multiple different stimuli (pH changes, temperature variations, oxidative conditions) rather than requiring separate encapsulation systems for each stimulus type

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The capsule wall is constructed from composite materials including pH-sensitive polymers, temperature-sensitive lipids, and disulfide cross-linked networks, combining multiple functional components with different stimulus-response characteristics to achieve multi-stimuli responsiveness while maintaining structural integrity

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If encapsulation is used to protect chemically unstable odorants, then stability is improved, but the release timing cannot be controlled for delayed release applications

Engineering Contradiction:

Improvechemical stability of active agentVSAvoidrelease timing control

Core Design Contradiction:

Stability of the object's compositionVSDuration of action of moving object

Solution Approach 1:

The encapsulation system exploits changes in environmental parameters (pH, temperature, oxidation state) to trigger release, where the capsule wall properties change in response to these parameter variations, enabling controlled release timing based on environmental conditions rather than immediate release upon contact

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If single-stimulus encapsulation systems are used, then the encapsulation process is simpler, but the application versatility across different industries is limited

Engineering Contradiction:

Improveencapsulation process simplicityVSAvoidapplication range

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The multi-stimuli responsive capsule system can be applied across multiple industries (cosmetics, textiles, paints, detergents, pharmaceuticals) using the same basic encapsulation platform, where the specific stimulus-response characteristics can be tuned by selecting appropriate polymer-lipid-disulfide compositions without requiring fundamentally different encapsulation processes for each application

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 microparticles provide controlled and sustained release of active agents, enhancing their stability and remanence, and can be tailored for specific applications in cosmetics, textiles, paints, and detergents, offering improved mechanical strength and environmental sustainability.

Implementation Method 1

at least one solid-liquid phase change material with a phase transition temperature ranging from 20 to 90° C.

Methodology Applied

Scientific EffectPhase transition: Phase Change

Implementation Method 2

coacervation of the HASE type acrylic polymer to lead to the said aqueous dispersions of microparticles

Methodology Applied

Scientific EffectCoacervation: Coacervate

Data Source

PatentUS9439870B2Active agent microparticles

Publication Date: 2016.09.13 COATEX SA

AI summary

The present invention concerns polymeric-enveloped microparticles including at least one HASE type acrylic copolymer, at least one solid-liquid phase change material with a phase transition temperature ranging from 20 to 90° C., and at least one active agent. In particular, the microparticles include at least one HASE type acrylic copolymer including at least one anionic monomer with a polymerizable vinyl group and a carboxyl group, at least one non-ionic hydrophobic monomer with a polymerizable vinyl group, and at least one alkoxylated associative macromonomer with a polymerizable vinyl group and a hydrophobic hydrocarbon chain.