Construction of nanostructured DNA harbouring phosphorodiamidate morpholino oligonucleotide for controlled tissue distribution in mice

Abstract

Phosphorodiamidate morpholino oligonucleotides (PMOs) are a class of antisense oligonucleotides used in the treatment of neuromuscular diseases. Their major drawbacks are high blood clearance and poor cellular delivery. Previously, we demonstrated that tripod-like nanostructured DNA, or tripodna, was efficiently taken up by macrophages and dendritic cells. In this study, we used iodine-125(¹²⁵I)-labelled PMOs, designed a tripodna harbouring an ¹²⁵I-PMO (¹²⁵I-PMO/tripodna), and evaluated whether this tripodna could control the pharmacokinetic properties of PMO. Gel electrophoresis showed that ¹²⁵I-PMO was almost completely incorporated into the tripodna. Compared to ¹²⁵I-PMO, ¹²⁵I-PMO/tripodna was more efficiently taken up by macrophage-like RAW264.7 cells. Moreover, after intravenous injection into mice, the area under the plasma concentration–time curve of ¹²⁵I-PMO/tripodna was significantly larger than that of ¹²⁵I-PMO. The distribution of ¹²⁵I-PMO/tripodna in the liver and spleen at 24 h was 32- and 51-fold higher than that of ¹²⁵I-PMO, respectively. The fractionation of liver cells revealed that non-parenchymal cells were the major cells contributing to the hepatic uptake of ¹²⁵I-PMO/tripodna. These results indicate that tripodna has the potential to deliver PMO, particularly to the liver and spleen.

Keywords:

• Word
• drug targeting
• nanotechnology
• oligodeoxynucleotides (ODNs)
• pharmacokinetics
• targeted drug delivery

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by Grants-in-Aid for Scientific Research (B) (23390010 and 26293008) from the Japan Society for the Promotion of Science and by JST CREST grant number JPMJCR1521, Japan.