A Visual Raman Nano-Delivery System Based on Thiophene Polymer for Microtumor Detection

Area of Science:

• Biomaterials Science
• Nanotechnology
• Medical Imaging

Background:

• Visual Raman nano-delivery systems (NS) are crucial for tumor visualization and diagnosis.
• Thiophene-based polymers offer biocompatibility but struggle with near-infrared (NIR) excitation and fluorescence interference.
• Existing thiophene materials have absorption spectra misaligned with NIR light, limiting Raman enhancement.

Purpose of the Study:

• To develop a novel donor-acceptor (D-A) structured thiophene-based polymer, PBDB-T, for enhanced visual Raman nano-delivery systems.
• To overcome the limitations of traditional thiophene materials in NIR excitation and fluorescence interference.
• To demonstrate the efficacy of PBDB-T as a visual Raman NS for in vivo microtumor diagnosis.

Main Methods:

• Synthesized a donor-acceptor (D-A) structured thiophene-based polymer, PBDB-T.
• Characterized PBDB-T's optical properties, including bandgap and absorption spectrum, confirming NIR region extension.
• Evaluated PBDB-T's performance as a visual Raman NS using 785 nm excitation for in vivo microtumor imaging.

Main Results:

• PBDB-T exhibits a narrow bandgap (2.63 eV) and red-shifted absorption into the NIR region.
• Achieved ultra-strong pre-resonant Raman enhancement with 785 nm excitation, free from fluorescence interference.
• Successfully diagnosed microtumor regions (0.5 mm × 0.9 mm) and deeper tissues in vivo, with a circulation half-life of 14.5 hours.

Conclusions:

• PBDB-T is a promising NIR-excited visual Raman NS for sensitive microtumor diagnosis.
• The D-A structure effectively modulates optical properties for enhanced Raman imaging.
• This research introduces a new platform for visualized drug delivery systems with potential for targeted therapies.