Transdermal Delivery of Antisense Oligonucleotides Can Induce Changes in Gene ExpressionIn Vivo

Abstract

The potential for using antisense compounds as therapeutic agents has generated great enthusiasm. Strategies for delivery of these compounds are, therefore, of great interest. Transdermal iontophoresis has been used successfully as an enhancement technique for the transdermal delivery of these compounds in vitro. The effectiveness of using percutaneous penetration as a means to deliver therapeutic levels of these compounds in vivo, however, remains to be demonstrated. The purpose of this work was to demonstrate the ability of iontophoretically delivered compounds to alter enzyme levels in the intact rat. A C5 propyne-modified phosphorothioate oligonucleotide (PS-ODN) targeted to the cytochrome p450-3A2 (CYP3A2) mRNA translational start site and the reverse sequence, used as a control, were synthesized. A patch containing either an oligonucleotide or a buffer control was placed on the animal's back, and an iontophoretic current of 0.5 mA/cm2 was applied for 3.5 hours. Twenty-four hours later, CYP3A2 levels were measured noninvasively using the midazolam-induced sleeping rat model. Liver and small intestinal microsomes were made after completion of sleep studies and assayed for CYP3A2, CYP1A1/2, CYP2B1/2, and CYP2E1. Midozolam-treated animals with antisense to CYP3A2 slept significantly longer than did the controls (p < 0.05). CYP3A2 levels were significantly lower in liver microsomes from antisense-treated animals than in either buffer control (p < 0.001) or reverse sequence animals (p < 0.05). The reverse sequence was also significantly different from the buffer control (p < 0.01), indicating a nonspecific effect of the PS background. Nontarget cytochrome levels were not altered by treatment. There were no significant differences in small intestine CYP3A2 levels between treatment groups. These data demonstrate that transdermally delivered PS-ODN can reach concentrations sufficient to induce changes in specific target enzymes in vivo. Further studies are warranted to investigate potential uses for these molecules.

Improvement of dermatitis by iontophoretically delivered antisense oligonucleotides for interleukin-10 in NC/Nga mice

“…On the other hand, only low radioactivity was observed in the anodal gel, the skin under it, and other tissues (blood, liver, spleen, and kidney). Although AS6 might distribute in other tissues (eg small intestine, urine), 25 radioactivities of these tissues were not determined.…”

Topical Delivery of Anti-sense Oligonucleotides Using Low-Frequency Sonophoresis

“…The highly ordered structure of lipid bilayers confers upon the SC an impermeable character. Different techniques, such as iontophoresis (6)(7)(8), electroporation (9,10), chemical enhancers (11), and microprojections (12) have been used to enhance transdermal and topical delivery of antisense oligonucleotides.…”

Topical delivery of DNA oligonucleotide to induce p53 generation in the skin via thymidine dinucleotide (pTT)-encapsulated liposomal carrier

“…[20][21][22] The results were effective and appeared promising for clinical application. Although the delivery efficiency showed improvement, some methods caused skin irritation.…”