Fluid-Mediated Laser Cell Ablation in Microfluidic Devices

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Solution Overview

Problem

Current methods for isolating cells from formalin-fixed paraffin-embedded tissue samples lack out-of-plane (z-axis) resolution, leading to low recovery rates and potential cell damage due to direct laser impingement, restricting analysis to two-dimensional studies and preventing the conservation of spatial and morphological information.

Innovation Solution

A method using a microfluidic device where a laser impinges on a fluid proximate to the tissue sample, causing fluid cavitation to ablate cells without direct contact, allowing for the collection and analysis of cells with preserved spatial information, and enabling three-dimensional visualization and molecular analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If direct laser impingement is used to ablate cells from tissue sample, then cell ablation efficiency is improved, but cell damage increases and recovery rate decreases

Engineering Contradiction:
Improvecell ablation efficiencyVSAvoidcell damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a fluid intermediary between the laser and tissue sample. The laser energy is first absorbed by the fluid, generating cavitation bubbles that then contact and ablate the cells. This indirect mechanism allows efficient cell ablation while avoiding direct laser damage to cellular components and underlying tissue layers.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the phase transition of the fluid from liquid to vapor through laser-induced cavitation. The rapid formation and collapse of cavitation bubbles in the fluid generates mechanical forces that efficiently ablate cells without requiring direct laser contact with the tissue, thereby reducing thermal damage.

Inventive Principle:
Principle #36Phase transitions

2Manufacturing precision

If traditional LCM techniques are used, then two-dimensional cell isolation is achieved, but out-of-plane resolution and three-dimensional analysis capability are lost

Engineering Contradiction:
Improvecell isolation precisionVSAvoidspatial information
Core Design Contradiction:
Manufacturing precisionVSLoss of information

Solution Approach 1:

The patent transitions from two-dimensional LCM to three-dimensional analysis by enabling selective ablation of cells at different depths (z-axis) within the tissue sample. The fluid-mediated laser ablation allows penetration and selective targeting of cells throughout the tissue thickness, preserving and enabling analysis of spatial information in all three dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If laser energy is directed directly at tissue sample, then cell ablation is achieved, but underlying cell layers are damaged

Engineering Contradiction:
Improvecell ablation rateVSAvoidunderlying cell layer integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The fluid acts as an intermediary that absorbs and transforms laser energy into cavitation bubbles. These bubbles selectively ablate target cells while the fluid medium protects underlying cell layers from direct laser exposure, maintaining their integrity for subsequent analysis or sequential ablation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach enhances sampling efficiency and reduces cell damage, enabling effective three-dimensional analysis and preservation of spatial information, improving the quality of cell samples and study results.

Implementation Method 1

causing fluid cavitation of said flowing first fluid to thereby hydrodynamically ablate a first set of one or more cells from the tissue sample

Methodology Applied
Scientific EffectFluid cavitation: Cavitation

Implementation Method 2

powering a laser to direct laser energy into the channel to impinge upon the first fluid proximate a first region of the tissue sample

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3436564B1Method for dissecting and analyzing individual cell samples
Publication Date: 2023.09.27 BIOSYNTAGMA LLC
  • EP3436564B1 patent drawingFigure 1
  • EP3436564B1 patent drawingFigure 2~3
  • EP3436564B1 patent drawingFigure 4~5

AI summary

A method for dissecting and collecting one or more cells from a tissue sample fixed to an inner surface of a microfluidic device is described. The tissue sample is in fluid communication with a channel having an inlet end and an outlet end defined by the microfluidic device. The method comprises flowing a first fluid through the channel with a fluid flow from the inlet end to the outlet end; powering a laser to direct laser energy into the channel to impinge upon the first fluid proximate a first region of the tissue sample and cause fluid cavitation to thereby ablate a first set of one or more cells from the tissue sample; and collecting the first set of one or more cells within a first sample container coupled to the outlet end.