Tumor-responsive fluorescent light-up probe based on a gold nanoparticle/conjugated polyelectrolyte hybrid

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Tumor microenvironments are often characterized by lower extracellular pH (pH(e)) compared to normal tissues.
• Developing sensitive and specific probes for tumor detection is crucial for early diagnosis and treatment.

Purpose of the Study:

• To design and characterize a tumor-responsive nanoprobe for imaging acidic tumor microenvironments.
• To investigate the probe's fluorescence 'turn-on' mechanism in response to pH changes.
• To evaluate the probe's efficacy for in vivo tumor imaging.

Main Methods:

• Fabrication of a hybrid nanoprobe using gold nanoparticles (AuNPs) and a cationic conjugated polyelectrolyte (CPE).
• Utilizing pH-triggered charge-reversible polymer deposition onto AuNPs via electrostatic interactions.
• Characterization of the nanoprobe's size, morphology, and fluorescence response to varying pH conditions.
• In vitro and in vivo evaluation of the nanoprobe for tumor imaging.

Main Results:

• The hybrid nanoprobe exhibited a 'turn-on' fluorescence response in acidic conditions (pH ≈ 6.5) due to charge repulsion between CPE and AuNPs.
• The probe demonstrated minimal fluorescence in physiological conditions (pH ≈ 7.4) owing to fluorescence quenching.
• Dynamic light scattering confirmed a monodispersed particle size of approximately 68.3 nm.
• In vivo studies showed specific accumulation of the nanoprobe in tumor tissues with enhanced fluorescence.

Conclusions:

• The developed tumor-responsive nanoprobe effectively visualizes acidic tumor microenvironments through fluorescence 'turn-on'.
• The probe's ability to accumulate in tumors and exhibit light-up fluorescence presents a promising tool for tumor imaging and identification.
• This technology offers new avenues for non-invasive cancer diagnosis and monitoring.