Nanovesicles and Human Skin Interaction: A Comparative Ex-Vivo Study.

Area of Science:

• Pharmacology and Drug Delivery
• Materials Science
• Biomedical Engineering

Background:

• Nanovesicular systems offer potential for topical drug delivery to treat skin conditions.
• Understanding nanovesicle biodistribution is key to assessing their transdermal capabilities.
• Phosphatidylcholine-based nanovesicles, including liposomes and ethosomes, are investigated for skin applications.

Purpose of the Study:

• To investigate the influence of production methods on nanovesicle characteristics.
• To compare the transdermal potential of liposomes and ethosomes produced via microfluidics and solvent injection.
• To evaluate the role of ethanol concentration in nanovesicle formulation and skin penetration.

Main Methods:

• Photon Correlation Spectroscopy (PCS) for size distribution analysis.
• Cryogenic Electron Microscopy (Cryo-EM) and Transmission Electron Microscopy (TEM) for ultrastructural and morphological evaluation.
• Hyperspectral Dark-field Microscopy and Small-Angle X-ray Scattering (SAXS) for detailed characterization.
• Human skin explants in a bioreactor model to assess transdermal passage.

Main Results:

• Ethanol injection method yielded smaller nanovesicles (approx. 140 nm) compared to microfluidics (approx. 230 nm).
• The solvent injection procedure influenced the uni- or multilamellar structure of the vesicles.
• Ultrastructural analysis confirmed intact nanovesicles crossing skin layers, with ethosomes from water injection demonstrating superior transdermal potential.
• Ethanol was identified as a significant penetration enhancer.

Conclusions:

• Production method significantly impacts nanovesicle size, morphology, and skin penetration.
• Ethosomes prepared via water injection exhibit enhanced transdermal delivery potential.
• Ethanol plays a crucial role in enhancing the skin penetration of nanovesicular systems.