Intradermal Delivery of Antisense Oligonucleotides by the Pulse Depolarization Iontophoretic System

Abstract

Antisense oligonucleotides designed to hybridize specifically to heterogeneous nuclear RNA or mature mRNA sequences have been shown to inhibit the expression of numerous genes both in vitro and in vivo.2,3) They have been considered as a promising candidate for nucleic acid drugs to realize gene-specific therapeutics for the treatment of malignant, viral, inflammatory, and autoimmune diseases. CD4ϩ helper T (Th) cells have been subdivided into at least two subsets, Th1 and Th2, on the basis of their cytokine secretion. 4,5) The balance of Th1 and Th2 cells is relevant to the outcome of immunologically mediated clinical syndromes, suggesting that Th2 is predominant in atopic dermatitis (AD).6) Interleukin-10 (IL-10) is initially characterized as a counter-regulatory cytokine for Th1 development, 4) and the overexpression of IL-10 in AD may contribute to the down-regulation of Th1 response. 7,8) Therefore, the regulation of IL-10 production may provide a potentiality for the immunotherapeutic intervention of AD. We reported that 18-mer antisense phosphorothioate oligonucleotide (S-oligo) hybridizing to the sequence of the 3Ј-untranslated region of mouse IL-10 mRNA inhibits the IL-10 production in macrophages.9) IL-10 antisense oligonucleotides may have a potentiality for AD treatment, provided that the antisense oligonucleotide can be delivered to the IL-10 producing cells such as macrophages, 7,10) dendritic cells, 10) Langerhans' cells, 11) keratinocytes, 11) and T cells 12) in the skin. In general, oligonucleotides are membrane-impermeable due to their high ionization, low-lipophilicity and high molecular weight. There are some reports on the improvement of transdermal delivery of antisense oligonucleotides across the stratum corneum with absorption enhancers 13) or by iontophoresis [14][15][16][17] and electroporation. 18,19) Iontophoresis is classified by the current flow pattern into constant direct current (CDC), pulse direct current (PDC), and pulse depolarization current (PDP). CDC iontophoresis is the most common, but its use is sometimes restricted by irritation attributed to the skin polarization. PDP iontophoresis provides a high frequency electric pulse and opens a depolarization circuit between pulses, so that the skin irritation is subsequently less in spite of the relatively high current density. 20) However, there is no paper on the iontophoretic delivery of antisense oligonucleotides using PDP iontophoresis.In the present study, we examined the permeation of phosphodiester oligonucleotide (D-oligo) having the antisense sequence to mouse IL-10 mRNA through isolated hairless mouse skin using PDP iontophoresis in vitro. To acquire basic information on the skin permeation of antisense oligonucleotides, D-oligo was used. In this paper, the advantages of PDP iontophoresis, permeation characteristics and the distribution and stability of D-oligo are discussed. It was observed that D-oligo could be delivered into the shallow layer of the skin effectively by PDP iontophoresis. Pharmacy and Life Science...

Princípios básicos e aplicação da iontoforese na penetração cutânea de fármacos

“…Portanto, a presença de outros íons pode reduzir o fluxo do fármaco e, conseqüentemente, sua permeação cutânea. [75][76][77][78][79] O fluxo eletrorrepulsivo de cada íon está relacionado com sua mobilidade elétrica e concentração, como mostra a Equação 4. Dessa forma, aumentando-se a concentração de moléculas competidoras de alta mobilidade no sistema, o fluxo do fármaco é certamente diminuído, e o inverso ocorre quando se compara o fluxo deste fármaco na presença de moléculas competidoras com baixa mobilidade e mesma concentração.…”

Reverse iontophoresis: A non-invasive technique for measuring blood lactate level

“…Use of direct current (dc) iontophoresis has been reported to cause adverse effects as a result of skin polarization, including electric burns, stinging or erythema [41][42][43][44][45][46][47]. Therefore, the application of dc iontophoresis has been limited to a period of approximately 15 min.…”

“…Therefore, the application of dc iontophoresis has been limited to a period of approximately 15 min. To avoid adverse effects, the use of pulsed dc or alternative current (ac) iontophoresis as a replacement to dc iontophoresis has also been studied [43,46,[48][49][50][51][52][53][54]. Higuchi et al [50] and Li et al [51] confirmed the electrophoretic effect of square-wave ac (i.e.…”

Desenvolvimento de sistemas de liberação para a administração tópica passiva e iontoforética do minoxidil no tratamento da alopecia androgênica

“…A eletrorrepulsão (Figura 9A) refere-se ao movimento ordenado de íons na presença de uma corrente elétrica aplicada ao meio. A presença de outros íons no sistema pode reduzir o fluxo do fármaco e, conseqüentemente, sua permeação (ARAMAKI et al, 2003;KOCHHAR;IMANIDIS, 2004;NUGROHO et al, 2005;SYLVESTRE et al, 2008). O fluxo eletrorrepulsivo de cada íon está relacionado com sua mobilidade elétrica e concentração.…”