Biocompatible Ionic Liquid Enhances Transdermal Antigen Peptide Delivery and Preventive Vaccination Effect

Area of Science:

• Pharmaceutical Sciences
• Biotechnology
• Materials Science

Background:

• Ionic liquids (ILs) are emerging as advanced solvents for drug delivery systems.
• Biocompatibility is crucial for next-generation IL-based drug delivery systems.
• Choline-fatty acid ([Cho][FA]) ILs offer a biocompatible alternative for drug solubilization.

Purpose of the Study:

• To evaluate biocompatible [Cho][FA] ionic liquids for transdermal drug delivery.
• To investigate the potential of ILs in enhancing antigen peptide delivery through the skin.
• To assess the efficacy and safety of IL-mediated transcutaneous vaccination.

Main Methods:

• Screening of various fatty acids (C8-C18:1) for biocompatibility and skin permeability enhancement.
• Formulation of an antigen peptide with [Cho][C18:1] IL and an oil-based penetration enhancer.
• Quantification of transdermal peptide flux using an in vitro skin model.
• Evaluation of in vivo anti-tumor efficacy and skin irritation using histological studies.

Main Results:

• Choline-18:1 (oleic acid) ([Cho][C18:1]) was selected for its low cytotoxicity and ability to enhance skin permeability.
• Transdermal delivery of the antigen peptide showed a 28-fold increase in flux using the IL formulation compared to an aqueous vehicle.
• Transcutaneous vaccination mediated by the IL formulation effectively suppressed tumor growth in vivo.
• In vitro and in vivo studies confirmed the formulation's lack of skin irritation.

Conclusions:

• Biocompatible ILs, specifically [Cho][C18:1], are effective in enhancing transdermal antigen peptide delivery.
• IL-mediated dissolution in oil-based enhancers offers a promising strategy for transdermal drug delivery and vaccination.
• The developed formulation demonstrates good efficacy and safety for transcutaneous vaccination.