Yingtai: Mechanism of Anti-Phototoxicity Reagents

Yingtai: Mechanism of Anti-Phototoxicity Reagents  

I. Core Mechanisms of Anti-Phototoxicity Reagents  

1. Reactive Oxygen Species (ROS) Scavenging  

   • Direct Quenching:  

     o Trolox (water-soluble vitamin E analog): Captures ROS (e.g., ·OH, O₂⁻) via phenolic hydroxyl groups, preventing lipid peroxidation and protein damage.  

     o Ascorbic acid (vitamin C): Neutralizes ROS through reductive action, particularly effective in protecting mitochondrial membrane potential.  

   • Enzyme-Assisted Systems:  

     o Oxyrase (oxygen-depleting enzyme): Reduces dissolved oxygen in the environment, minimizing singlet oxygen (¹O₂) generation, suitable for photosensitive dyes (e.g., FITC) in fluorescence imaging.  

2. Fluorescent Probe Stability Enhancement  

   • Anti-Fading Agents:  

     o DABCO (1,4-diazabicyclo[2.2.2]octane): Inhibits interactions between fluorescent molecules and oxygen, delaying fluorescence quenching (extends Cy5 labeling lifespan by 3–5 times).  

     o Cyclodextrin encapsulation: e.g., β-cyclodextrin shields hydrophobic dyes (e.g., DiI), reducing photooxidation reactions.  

3. Cellular Metabolic Protection  

   • Energy Supply Maintenance:  

     o Sodium pyruvate: Supplies tricarboxylic acid (TCA) cycle intermediates, enhances ATP synthesis, and mitigates laser-induced energy depletion.  

     o Glucose oxidase-catalase system: Dynamically regulates microenvironmental oxygen levels, balancing oxidative stress and imaging requirements.  

4. Membrane Structure Stabilization  

   • Cholesterol Analogs:  

     o Methyl-β-cyclodextrin: Repairs laser-induced micropores in cell membranes, preventing calcium influx-induced apoptosis.  

II. Technical Applications and Performance Comparison  

III. Cutting-Edge Advances  

1. Nanocarrier Delivery:  

   o Silica nanoparticles loaded with Trolox (mito-Trolox) enable targeted delivery to mitochondria, improving local ROS scavenging efficiency by 80%.  

2. Genetically Encoded Protectants:  

   o Expression of antioxidant cytochrome b₅ reductase (CYB5R) achieves endogenous resistance to phototoxicity.