Fluorescent Arylphosphonic Acids: Synergic Interactions between Bone and the Fluorescent Core

Area of Science:

• Materials Science
• Biomedical Imaging
• Organic Chemistry

Background:

• Calcifications, particularly hydroxyapatite (HAP), are implicated in various pathologies.
• Developing sensitive and specific fluorescent probes for HAP detection is crucial for diagnosis and monitoring.

Purpose of the Study:

• To synthesize and evaluate the third generation of fluorescent probes based on arylphosphonic acids for targeting HAP.
• To compare the efficacy of meta- and para-substituted porphyrin-based probes.

Main Methods:

• Synthesis of porphyrin-based arylphosphonic acids and their diesters.
• Evaluation of probe sensitivity and specificity towards HAP in rat bone sections.
• Assessment of cellular uptake and preliminary toxicity of the probes.

Main Results:

• The synthesized probes, particularly those with extended conjugation via sp2-bonded phosphonic acid units, exhibit enhanced fluorescence upon HAP binding.
• Probes demonstrated high sensitivity for HAP detection in biological samples.
• The probes are readily internalized by cells, and one derivative shows lower toxicity.

Conclusions:

• The novel arylphosphonic acid-based fluorescent probes are effective for detecting HAP calcifications.
• These probes hold promise for applications in bone metabolism monitoring and imaging of vascular and soft tissue calcifications, including potential use in breast cancer diagnosis.