Effect of topical interferon-γ gene therapy using gemini nanoparticles on pathophysiological markers of cutaneous scleroderma in Tsk/+ mice.

Scleroderma is a chronic disorder manifested by excessive synthesis and deposition of collagen in skin and connective tissue, vascular abnormalities, and autoimmunity. Using microarray and real-time PCR data, we show that intradermally expressed interferon γ (IFN-γ), generated after intradermal injection of IFN-γ-coding plasmid, and non-invasive topical nanoparticle (TNP) treatment with IFN-γ-coding plasmid, decreased collagen synthesis (via the Jak/Stat 1 pathway), upregulated Th1 cytokine levels, and downregulated the profibrotic cytokine Transforming growth factor β and the Smad pathways in the Tsk/+ (tight-skin scleroderma) mouse model. The TNP gene delivery system was constructed from gemini surfactant 16-3-16 and IFN-γ-coding plasmid. Topical administration of IFN-γ-coding plasmid in TNPs was effective in expressing IFN-γ levels after a 20-day treatment regimen without increased TLR4, CCL2, CCL11 and CCR2 mRNA levels that were observed in injected animals, signs considered to be innate responses to injury. The more uniform transgene IFN-γ expression caused significant (70-72%) collagen reduction, as assessed by reverse transcription real-time PCR. These results demonstrate efficient in vivo transfection using a gemini surfactant-based TNP delivery system able to modulate excessive collagen synthesis in scleroderma-affected skin.