NIR Nanoparticle Chemiluminescent Probe for In Vivo Enzyme Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting enzymatic activity, such as imaging myeloperoxidase activity, face limitations due to the short wavelength of chemiluminescence light emitted, which has limited penetration through tissues and can cause immune reactions or tissue autofluorescence interference.
Innovation Solution
The use of near-infrared (NIR) nanoparticles that couple with chemiluminescent enzymatic probes like luminol to red-shift the light emission, enhancing detection sensitivity and avoiding exogenous enzyme-related immune responses and autofluorescence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If chemiluminescent probes like luminol are used to detect enzymatic activity, then detection capability is provided, but tissue penetration is limited due to short wavelength light absorption
Solution Approach 1:
The patent introduces NIR nanoparticles as an intermediary between the chemiluminescent probe and the detector. The nanoparticles absorb the short-wavelength chemiluminescence and re-emit it at longer NIR wavelengths that penetrate tissue more effectively, thus mediating the energy transfer while overcoming the tissue absorption problem
Solution Approach 2:
The patent changes the wavelength parameter of the emitted light from visible range (425 nm peak for luminol) to near-infrared range through the use of NIR nanoparticles. This parameter change enables deeper tissue penetration while maintaining the chemiluminescent detection mechanism
2Illumination intensity
If exogenous enzymes like luciferase are used for bioluminescence imaging, then light generation capability is improved, but immune reactions occur
Solution Approach 1:
The patent utilizes the organism's own endogenous enzymes (myeloperoxidase, NADPH oxidase) that are already present in inflammatory cells to generate the chemiluminescence signal. This eliminates the need for introducing exogenous enzymes, thereby avoiding immune reactions while maintaining light generation capability
Solution Approach 2:
The patent extracts and eliminates the problematic exogenous enzyme component from the imaging system, relying instead on endogenous enzymatic activity that is naturally present in the diseased tissue, thus removing the source of immune reactions
3Measurement precision
If exogenous excitation light is used for FRET imaging, then molecular proximity detection is enabled, but tissue autofluorescence interferes with detection
Solution Approach 1:
The patent employs chemiluminescence which provides spontaneous, periodic light emission without continuous external excitation. This eliminates the constant excitation light source that causes autofluorescence, while still enabling temporal detection of enzymatic activity through the periodic nature of the chemical reaction
Solution Approach 2:
The patent replaces the optical excitation mechanism (mechanical light source) with a chemical energy conversion mechanism (chemiluminescence). This substitution eliminates the need for external excitation light, thereby removing the source of autofluorescence interference while maintaining the ability to detect molecular events
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 allows for highly sensitive detection of enzymatic activity in vivo, particularly ROS production, with improved tissue penetration and reduced immune response, enabling effective monitoring of inflammation and cancer detection.
Implementation Method 1
chemiluminescent enzymatic reaction that monitors enzyme activity
Implementation Method 2
near-infrared (NIR) nanoparticle... the nanoparticle emits light (e.g., NIR) upon exposure to the chemiluminescence
Implementation Method 3
the NADPH mediates a respiratory burst and converts O2 to superoxide anion (O2°-)
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Compositions and methods are described for detecting enzyme activity in a live organism (e.g., animal) are provided.