Poly(ε-caprolactone) modified organic dyes nanoparticles for noninvasive long term fluorescence imaging

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Fluorescence Spectroscopy

Background:

• Organic dyes face limitations in biomedical use, including self-quenching, poor stability, and low water solubility.
• These issues hinder their application in sensitive biological imaging and diagnostics.
• Developing stable, bright, and water-soluble organic dyes is crucial for advancing biomedical research.

Purpose of the Study:

• To develop polymer-modified organic dyes with enhanced fluorescence intensity, photostability, and water solubility.
• To investigate the effect of polymer length on dye performance and aggregation.
• To demonstrate the utility of these optimized dyes in long-term cellular fluorescence imaging.

Main Methods:

• Organic dyes were modified by initiating polymerization, controlling polymer length via monomer concentration.
• The relationship between polymer molecular weight and dye aggregation (π-π stacking) was analyzed.
• Nanoparticles were fabricated using the optimized polymer-modified dyes for cellular uptake studies.

Main Results:

• Polymer modification successfully inhibited π-π stacking and fluorescence quenching in π-conjugated organic dyes.
• An optimal polymer molecular weight significantly enhanced fluorescence intensity and photostability.
• Fabricated nanoparticles demonstrated efficient cell uptake and enabled long-term cellular fluorescence imaging.

Conclusions:

• Polymer modification is a viable strategy to overcome the limitations of organic dyes for biomedical applications.
• Optimized polymer-dye conjugates exhibit superior optical properties and stability.
• This approach expands the potential of organic dyes in advanced biological imaging and diagnostics.