Inherently Photodegradable Hydrogels for Microfabrication

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Solution Overview

Problem

Current photodegradable hydrogels and organogels require external photosensitive groups for degradation, increasing synthetic complexity and limiting their structural flexibility and practical applications in microfabrication and microengineering.

Innovation Solution

Development of inherently photodegradable hydrogels and organogels without external photosensitive groups, utilizing polymer chains with repeating units that undergo photolysis under UV light, allowing for controlled degradation and sophisticated microfabrication without additional chemicals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If external photosensitive groups are introduced to achieve photodegradability, then photodegradation function is achieved, but synthetic complexity increases and structural flexibility decreases

Engineering Contradiction:
Improvephotodegradation functionVSAvoidsynthetic complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and removes the external photosensitive groups from the hydrogel system. Instead of using separate photosensitive additives or crosslinkers, the photodegradability is achieved through the inherent polymer backbone structure itself, eliminating the need for additional photosensitive components and simplifying the overall system composition

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the chemical parameter of the polymer backbone by incorporating photolabile bonds (such as o-nitrobenzyl esters, coumarins, or disulfide bonds) directly into the repeating units of the polymer chain. This parameter change enables the polymer to undergo photolysis under UV irradiation, achieving controlled degradation without external photosensitive groups

Inventive Principle:
Principle #35Parameter changes

2Reliability

If external photosensitive groups are introduced to achieve photodegradability, then photodegradation function is achieved, but structural flexibility and diversity are reduced

Engineering Contradiction:
Improvephotodegradation functionVSAvoidstructural flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention creates a universal polymer platform where the photodegradable repeating units can serve multiple functions: they provide the backbone structure, enable photodegradation, and allow for diverse side chain modifications. This multi-functionality approach maintains structural flexibility while achieving reliable photodegradation through the inherent polymer structure

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention applies local quality by placing photolabile bonds at specific positions within the polymer repeating units (such as in the backbone or as side chains), while allowing other parts of the polymer structure to maintain their functional properties. This localized approach enables photodegradation while preserving structural diversity and flexibility in other regions

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If photolithography is used for microengineering applications, then patterning capability is achieved, but additional chemicals and complexity are required

Engineering Contradiction:
Improvepatterning capabilityVSAvoidchemical complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention enables the hydrogel system to serve itself by incorporating inherent photodegradability into the polymer structure. When exposed to UV light through photomasks, the polymer backbone automatically undergoes photolysis and degradation without requiring external photosensitive groups, photoinitiators, or additional chemical agents, thus simplifying the microfabrication process

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

Enables straightforward preparation of patterned articles with controlled degradation kinetics, enhancing microfabrication capabilities and providing a versatile platform for microengineering applications such as three-dimensional cell cultures and drug delivery.

Implementation Method 1

polymer chains having repeating units of the general Formula (I) which undergo photolysis under UV light

Methodology Applied
Scientific EffectPhotolysis: Photodissociation

Data Source

PatentEP3502779B1Inherently photodegradable hydrogels or organogels for microfabrication
Publication Date: 2020.11.18 KARLSRUHER INST FUR TECH
  • EP3502779B1 patent drawingFigure 1~2
  • EP3502779B1 patent drawingFigure 3~4
  • EP3502779B1 patent drawingFigure 5~6

AI summary

The present invention relates to a photodegradable hydrogel or organogel which is used for manufacturing a patterned article, a method for degrading the photodegradable hydrogel or organogel, a corresponding patterned article, as well as the use of such a patterned article in microengineering, e.g. for three-dimensional cell culturing, for drug delivery, or for tissue-engineering.