Nanofibrous LPPO–Polycaprolactone Material for Enzymatic Drug Release

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Solution Overview

Problem

Existing nanofiber-based drug carriers release active substances uncontrolledly, leading to rapid concentration fluctuations, bacterial resistance, and instability under UV and thermal stress, complicating their use in topical therapies.

Innovation Solution

Combining polycaprolactone nanofibers with lipophosphonoxins (LPPO) to form a tightly bound material that releases the drug via enzymatic hydrolysis, controlled by the immune response, ensuring stability and controlled release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If drugs are mixed into polymer solution for electrospinning, then basic instrumentation can be used, but drug release is uncontrolled and rapid concentration increase occurs

Engineering Contradiction:
Improveease of preparationVSAvoidcontrolled drug release
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses a composite material system combining polycaprolactone polymer with lipophosphonoxin drugs, where the drug is covalently bonded to the polymer chains. This composite structure enables both ease of preparation through standard electrospinning and controlled drug release through enzymatic hydrolysis, resolving the contradiction between manufacturing simplicity and release control reliability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the drug-polymer interaction parameter from physical mixing to covalent bonding, and the release mechanism from simple diffusion to enzymatic hydrolysis. This parameter change transforms the release profile from rapid and uncontrolled to sustained and controlled, while maintaining compatibility with basic electrospinning instrumentation

Inventive Principle:
Principle #35Parameter changes

2Reliability

If diffusion-preventing layer is added for controlled release, then rapid concentration increase is prevented, but preparation procedures become more complex and expensive

Engineering Contradiction:
Improvecontrolled drug releaseVSAvoidpreparation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of adding a diffusion-preventing layer that would increase structural complexity, the patent changes the fundamental release mechanism parameter from diffusion-controlled to enzymatic hydrolysis-controlled. This approach achieves controlled release through the chemical bond stability of the drug-polymer conjugate, avoiding the need for additional layers or complex preparation procedures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs the body's own lipase enzymes as the release control mechanism. The drug is released through enzymatic hydrolysis by lipases naturally present at the application site, eliminating the need for externally controlled release systems or complex preparation procedures while achieving reliable controlled release

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If uncontrolled drug release occurs, then simple diffusion mechanism works, but bacterial resistance develops due to rapid concentration drop

Engineering Contradiction:
Improvesimple preparationVSAvoidbacterial resistance
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent changes the drug release kinetics parameter from rapid diffusion to sustained enzymatic hydrolysis. This parameter change maintains simple preparation methods while preventing bacterial resistance by ensuring continuous therapeutic drug levels through controlled release that matches the body's enzymatic activity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent ensures continuous therapeutic action by designing a release mechanism based on enzymatic hydrolysis that operates continuously as long as lipase enzymes are present. This continuous release prevents the concentration drop that leads to bacterial resistance, while the simple covalent bonding approach maintains ease of manufacture

Inventive Principle:
Principle #20Continuity of useful action

4Reliability

If some active substances are used, then antibacterial effect is achieved, but thermal and UV stability is low preventing sterilization

Engineering Contradiction:
Improveantibacterial effectVSAvoidthermal stability
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent uses a composite material system where lipophosphonoxin drugs are covalently bonded to polycaprolactone polymer. This composite structure provides both the required antibacterial effect and enhanced thermal and UV stability, as the polymer matrix protects the drug molecules from degradation during sterilization processes

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs lipophosphonoxin compounds that inherently possess high thermal and UV stability, allowing the material to withstand sterilization processes. The self-service aspect is that the material's own chemical structure provides the stability needed for sterilization without requiring additional protective measures

Inventive Principle:
Principle #25Self-service

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 LPPO-polycaprolactone combination provides stable, controlled drug release, preventing bacterial resistance and enabling effective treatment of infectious skin conditions without rapid concentration changes or toxicity.

Implementation Method 1

high voltage is applied between the two. Polymer solution is extruded from the capillary and formed into a thin stream of liquid by the electric field

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 2

Subsequently, the solvent evaporates and thin polymer fibers are formed and trapped on the collector

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

the activity of lipases and other hydrolytic enzymes is increased due to the increased immune response of the organism. Thus, LPPO is released at a rate proportional to the intensity of the immune response at the site of action

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP4161596B1Nanofibrous material particularly for topical use in therapies
Publication Date: 2025.08.06 UNIV KARLOVA V PRAZE
  • EP4161596B1 patent drawingFigure 1
  • EP4161596B1 patent drawingFigure 2
  • EP4161596B1 patent drawingFigure 3

AI summary

The invention discloses nanofibrous material particularly for topical use in therapies consisting of compound chosen from a group comprising lipophosphonoxins of general formula I, wherein R1 is (C8–C22)alkyl, hexadecyloxypropyl, tetradecyloxypropyl, tetradecyloxyethyl, or hexadecyloxyethyl, R2 is uracil, thymine, or cytosine, and R3 is primary, secondary, or tertiary amine, diastereomers and mixtures of diastereomers of compounds according to formula I, and their pharmaceutically acceptable salts and hydrates, incorporated into polyester-based nanofibers of general formula II, wherein m has a value of at least 1, and R is -H or (C1–C10)alkyl, or copolymers thereof.