Optical Studies of Nanodiamond-Tissue Interaction: Skin Penetration and Localization

Area of Science:

• Biomedical Optics
• Nanotechnology
• Dermatology

Background:

• Nanoparticles (NPs) are increasingly explored for biomedical applications, requiring understanding of their interaction with biological barriers like skin.
• Optical-spectroscopic methods offer non-invasive ways to study NP-skin interactions.
• Diamond nanoparticles (NDs) possess unique optical properties making them candidates for imaging and therapeutic delivery.

Purpose of the Study:

• To investigate the penetration of various diamond nanoparticles (NPs) into animal skin in vitro using multiple optical-spectroscopic techniques.
• To evaluate the suitability of different optical methods for visualizing nanodiamond (ND) skin interactions.
• To determine the optimal ND size and optical imaging modalities for studying skin penetration.

Main Methods:

• In vitro study using murine skin samples treated with nanodiamond (ND) water suspensions.
• Application of optical coherence tomography (OCT), confocal fluorescence microscopy, two-photon fluorescence microscopy, and fluorescence lifetime imaging (FLIM).
• Analysis of optical properties of NDs (3-150 nm) to correlate with imaging effectiveness.

Main Results:

• Nanodiamonds (NDs) of various sizes successfully penetrated the murine skin barrier in vitro.
• Particles around 100 nm were suitable for multimodal imaging across OCT and fluorescence microscopy techniques.
• All tested NDs were observed to penetrate epidermal layers and reach hair follicle niches.

Conclusions:

• Diamond nanoparticles (NPs) can effectively cross the skin barrier and localize within hair follicles.
• Multimodal optical imaging is a powerful approach for studying nanodiamond (ND)-skin interactions.
• NDs show promise for multifunctional applications in dermatology and drug delivery, facilitated by advanced imaging techniques.