Artificial Retina Dye Fixation via Segmented Washing

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Solution Overview

Problem

Existing methods for producing artificial retinas using organic dye compounds on polyethylene substrates face challenges with dye fixation, as the washing process with chlorobenzene leads to dissociation of the dye, making it difficult to determine completion and requiring a long time, which affects the efficiency and reliability of the artificial retina.

Innovation Solution

A method involving a first washing step with water to remove non-bonded dye and a second washing step with an organic solvent to minimize solvent-induced dissociation, including pretreatment with fuming nitric acid and diamine modification to enhance dye bonding, resulting in an artificial retina with improved mechanical properties and biocompatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If washing with chlorobenzene is used to remove unreacted dye, then the dye is removed, but dissociation of chemically bonded dye occurs and washing time becomes very long

Engineering Contradiction:
Improveamount of unreacted dye removedVSAvoidwashing time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The washing process is divided into two distinct stages: first washing with water to remove unreacted dye without causing dissociation, then washing with chlorobenzene to remove any remaining dye. This segmentation allows each washing step to be optimized for its specific purpose, preventing the dissociation problem while maintaining effective dye removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The water washing step is performed before the chlorobenzene washing step. This preliminary action removes the majority of unreacted dye under gentle conditions that do not cause dissociation, thereby reducing the burden on the subsequent chlorobenzene washing step and significantly shortening the overall washing time.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If washing with chlorobenzene is used to remove unreacted dye, then the dye is removed, but completion of removal cannot be determined and dissociation continuously occurs

Engineering Contradiction:
Improveamount of unreacted dye removedVSAvoidreliability of dye fixation
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The washing process is divided into two distinct stages: first washing with water to remove unreacted dye without causing dissociation, then washing with chlorobenzene to remove any remaining dye. This segmentation allows each washing step to be optimized for its specific purpose, preventing the dissociation problem while maintaining effective dye removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Water serves as an intermediary substance in the washing process. It is used first to remove unreacted dye under conditions that do not cause dissociation of chemically bonded dye. This intermediary step protects the bonded dye from the harsher chlorobenzene environment, ensuring reliable dye fixation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If polyethylene film is reacted with dye and washed with chlorobenzene, then dye is fixed, but the amount of dye fixed is not necessarily large

Engineering Contradiction:
Improveamount of dye fixedVSAvoidefficiency of dye fixation
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The polyethylene film undergoes preliminary treatment with fuming nitric acid and diamine modification before dye fixation. These preliminary actions enhance the reactivity and bonding capacity of the polyethylene surface, enabling more dye molecules to be effectively fixed during the subsequent dyeing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The chemical parameters of the polyethylene film are changed through nitric acid treatment and diamine modification. These parameter changes transform the inert polyethylene surface into a more reactive surface with enhanced dye-fixing capability, thereby increasing the amount of dye that can be effectively fixed.

Inventive Principle:
Principle #35Parameter changes

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

This method ensures reliable dye fixation, reduces washing time, and enhances the mechanical and biocompatibility properties of the artificial retina, allowing for effective receptor potential induction in optic nerves.

Implementation Method 1

a first pretreatment step of treating the substrate with fuming nitric acid

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

a second pretreatment step, after the first pretreatment step, of treating the substrate with a diamine

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 3

a bonding step, after the first and second pretreatment step, of immersing the substrate in a solution containing the organic dye compound to chemically bond the organic dye compound to the substrate

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 4

a first washing step of washing with water the substrate to which the organic dye compound has been chemically bonded

Methodology Applied
Scientific EffectWashing/Extraction: Liquid-Liquid Extraction

Implementation Method 5

a second washing step, after the first washing step, of washing with an organic solvent the substrate to which the organic dye compound has been chemically bonded

Methodology Applied
Scientific EffectWashing/Extraction: Liquid-Liquid Extraction

Data Source

PatentEP3127558B1Method for producing artificial retina
Publication Date: 2022.11.02 UNIV OKAYAMA
  • EP3127558B1 patent drawingFigure 1~2
  • EP3127558B1 patent drawingFigure 3~4
  • EP3127558B1 patent drawingFigure 5

AI summary

There is provided a method for producing an artificial retina in which an organic dye compound that induces a receptor potential responding to photostimulation is fixed on a polymer sheet substrate, comprising a bonding step of immersing the substrate in a solution containing the organic dye compound to chemically bond the organic dye compound to the substrate; a first washing step of washing with water the substrate to which the organic dye compound has been chemically bonded; and a second washing step of, after the first washing step, washing with an organic solvent the substrate to which the organic dye compound has been chemically bonded. Thus, there can be provided an artificial retina which has excellent mechanical properties such as elongation at break and good biocompatibility, and is capable of inducing a receptor potential responding to photostimulation with high sensitivity.