Conjugated Polymer Nanoparticles for Deep Tissue Fluorescence Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fluorescence microscopy techniques face limitations in biological imaging, particularly in vivo applications and deep tissue imaging due to autofluorescence, light absorption and scattering by tissues, and the use of toxic heavy metals in quantum dots, which hinder image quality and sensitivity.
Innovation Solution
Development of conjugated polymer nanoparticles that emit light in the far-red and near-infrared spectral window, free from toxic heavy metals, with controlled sizes and emission properties independent of particle diameter, using a modified reprecipitation approach to enhance imaging capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If quantum dots are used as fluorescent probes, then size-tunable fluorescent properties are achieved, but toxic heavy metals are introduced rendering them contraindicated for biological applications
Solution Approach 1:
The patent extracts and removes the toxic heavy metal component from the fluorescent probe system by replacing quantum dots with conjugated polymer nanoparticles that achieve similar size-tunable fluorescent properties through alternative mechanisms, specifically using polymer chain length and aggregation state control rather than quantum confinement in metal-based structures
Solution Approach 2:
The patent employs composite material design by creating conjugated polymer nanoparticles with specific molecular structures (incorporating electron-donating and electron-withdrawing units) that provide both the desired optical properties and biocompatibility, replacing the homogeneous metal-based quantum dot structure
2Measurement precision
If conventional fluorescence probes are used for deep tissue imaging, then signal detection is attempted, but light absorption and scattering by tissues hinders signal detection and acquisition speeds
Solution Approach 1:
The patent changes the optical parameters of the fluorescent probes by tuning the emission wavelength into the second near-infrared window (1000-1700 nm) where biological tissues exhibit minimal absorption and scattering, thereby optimizing the probes for deep tissue imaging applications and reducing energy loss in the tissue medium
3Measurement precision
If fluorescence microscopy is used for in vivo imaging, then high sensitivity detection is achieved, but autofluorescence of tissues increases background signal and decreases image contrast
Solution Approach 1:
The patent shifts the operating wavelength parameter to the second near-infrared window (1000-1700 nm) where biological tissues exhibit minimal autofluorescence, thereby maintaining high detection sensitivity while dramatically reducing background interference from tissue autofluorescence
4Illumination intensity
If conjugated polymer concentration is increased to enhance fluorescence signal, then emission intensity increases, but particle size increases affecting emission properties
Solution Approach 1:
The patent introduces dynamic control mechanisms where the nanoparticle formation process is optimized to achieve a stable size distribution that decouples emission intensity from particle size, allowing independent optimization of brightness and optical properties through controlled aggregation and self-assembly processes
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
These nanoparticles provide improved imaging sensitivity and reduced background noise, enabling deeper tissue penetration and safer biological imaging without the toxicity concerns of traditional quantum dots.
Implementation Method 1
The conjugated polymers and conjugated polymer nanoparticles have a maximum emission of light occurring within the far-red (FR)/near infrared (NIR) spectral window (between 650 nm and 950 nm) spectral window, or short-wavelength infrared (SWIR) spectral window (between 1,000 nm and 1,350 nm)
Data Source
AI summary
Described are conjugated polymers and conjugated polymer nanoparticles formed therefrom. The conjugated polymers and conjugated polymer nanoparticles have a maximum emission of light that occurs within a tissue transparent window of the electromagnetic spectrum. These emission properties are particle-size independent. The sizes of the conjugated nanoparticles are controlled by altering the concentration of the conjugated polymer used to make conjugated polymer nanoparticles. Also described are methods of making conjugated polymer nanoparticles that have larger sizes than have been traditionally reported, involving a modified reprecipitation approach. The conjugated polymers and/or conjugated polymer nanoparticles can be used as fluorescent probes in biological imaging.