Gene delivery into human skin in vitro using biphasic lipid vesicles

Area of Science:

• Biotechnology
• Dermatology
• Pharmaceutics

Background:

• Topical gene delivery offers non-invasive administration of vaccines and therapeutics.
• Developing effective delivery systems for plasmid DNA into viable skin layers is crucial.

Purpose of the Study:

• To quantitatively assess DNA delivery into excised human skin using a novel lipid-based biphasic system.
• To evaluate the efficacy of different biphasic vesicle formulations for transdermal macromolecule delivery.

Main Methods:

• In vitro evaluation of lipid-based biphasic vesicle formulations in flow-through diffusion cells using excised human breast skin.
• Quantitative PCR was used to measure plasmid DNA absorption after topical application and washing.
• Skin samples underwent tape-stripping and DNase treatment to isolate dermal absorption.

Main Results:

• Three formulations demonstrated significant dermal absorption compared to controls.
• Formulation 26-3-2-DNA achieved approximately 1x10^9 plasmid copies/cm^2 skin absorption.
• Other formulations showed absorption rates of 5x10^6 to 5x10^8 copies/cm^2 skin.

Conclusions:

• Biphasic vesicles successfully delivered significant quantities of plasmid DNA into the viable layers of human skin in vitro.
• This represents a major advance in transdermal delivery of large, charged molecules like plasmid DNA.
• The system shows potential for painless, non-invasive topical gene therapy and vaccination.