Noninvasive Nanodiamond Skin Permeation Profiling Using a Phase Analysis Method: Ex Vivo Experiments.

Area of Science:

• Biotechnology
• Nanotechnology
• Optical Imaging

Background:

• Carbon-based nanoparticles, specifically nanodiamonds (NDs), show promise for topical skin treatments.
• Noninvasive detection of NDs in skin layers is challenging due to tissue's optical properties.

Purpose of the Study:

• To adapt and apply the iterative multiplane optical properties extraction (IMOPE) technique for noninvasive detection of nanodiamonds in skin.
• To assess the penetration depth of nanodiamonds into different skin layers using the IMOPE technique.

Main Methods:

• Utilized the iterative multiplane optical properties extraction (IMOPE) technique, relying on absorption analysis for nanodiamond detection.
• Employed phase-image analysis reconstructed by the multiplane Gerchberg-Saxton algorithm.
• Conducted experiments using tissue-like phantoms and ex vivo pigskin, corroborated by TEM and Franz-cell analysis.

Main Results:

• The IMOPE technique successfully detected nanodiamonds in tissue-like phantoms.
• Ex vivo pigskin experiments demonstrated a gradual reduction in nanodiamond signal in deeper skin layers (epidermis, dermis, fat).
• Statistical analysis confirmed the significance of nanodiamond presence reduction in different layers (p < 10^-4, 10^-3, 10^-2).

Conclusions:

• The IMOPE technique provides a noninvasive method for profiling nanodiamond skin permeation.
• The study validates the capability of optical methods to track nanoparticle behavior within biological tissues.
• Results support the potential of nanodiamonds for targeted topical delivery applications.