Visualization Materials Using Silicon-Based Optical Nanodisks (ViSiON) for Enhanced NIR Imaging in Ophthalmology.

Area of Science:

• Biomedical Engineering
• Materials Science
• Optical Physics

Background:

• Developing advanced contrast agents is crucial for high-resolution medical imaging.
• Optical coherence tomography (OCT) requires agents with specific scattering properties for enhanced visualization.
• Biodegradable materials are desirable for biomedical applications to minimize long-term effects.

Purpose of the Study:

• To introduce ViSiON (visualization materials composed of silicon-based optical nanodisks) as a novel material for OCT imaging.
• To investigate the tunable optical and biodegradable properties of ViSiON.
• To evaluate ViSiON's potential as an OCT contrast agent for ophthalmic applications.

Main Methods:

• Numerical simulations to predict scattering properties based on nanodisk dimensions.
• Top-down patterning technique for synthesizing ViSiON with controlled diameter and thickness.
• Biodegradation studies in aqueous media with varying protein coatings.
• Validation of OCT imaging in small vessels using a retinal phantom and an ex ovo chick embryo model.

Main Results:

• ViSiON exhibits tunable near-infrared scattering properties controlled by the diameter-to-thickness ratio.
• A 50 nm thick ViSiON shows over 400 times higher scattering than 30 nm thick ViSiON.
• ViSiON demonstrates ≈95% biodegradability within 48 hours, tunable via protein coating.
• Successful OCT imaging of vessels <300 µm and enhanced protein membrane strength by 6.17 times in a chick embryo model.

Conclusions:

• ViSiON offers a unique combination of tunable NIR optical properties and biodegradability.
• ViSiON is a promising contrast agent for OCT, especially for ophthalmic imaging and diagnostics.
• The material's properties can be precisely controlled for specific biomedical applications.