A simple, noninvasive and efficient method for transdermal delivery of siRNA

Area of Science:

• Biotechnology
• Dermatology
• Molecular Biology

Background:

• Effective delivery of therapeutic agents is a major challenge for RNA interference (RNAi) applications.
• Transdermal delivery of nucleic acids, such as small interfering RNA (siRNA), remains difficult due to skin's barrier properties.

Purpose of the Study:

• To evaluate the potential of a synthetic peptide, ACSSSPSKHCG (TD-1), for transdermal delivery of siRNA.
• To investigate the mechanism of TD-1 mediated skin penetration and gene knockdown efficacy.

Main Methods:

• Co-administration of FITC-labeled TD-1 and FAM-labeled siRNA on rat footpad skin.
• Fluorescence microscopy to track distribution of TD-1 and siRNA.
• Transmission electron microscopy to examine skin structure changes.
• Quantification of target gene (GAPDH) levels after siRNA delivery.

Main Results:

• TD-1 and siRNA distributed uniformly from epidermis to subcutaneous tissue.
• TD-1 treatment induced transient openings in skin by affecting cell-cell junctions.
• Topical delivery of anti-GAPDH siRNA via TD-1 significantly reduced GAPDH levels within 72 hours.

Conclusions:

• TD-1 facilitates transdermal delivery of siRNA through follicle-free skin by creating transient pathways.
• This peptide-based system offers a novel mechanism for siRNA delivery into the epidermis for gene knockdown.
• The TD-1/siRNA system holds promise for developing topical siRNA-based therapies for skin conditions.