Selective Targeting of a Novel Vasodilator to the Uterine Vasculature to Treat Impaired Uteroplacental Perfusion in Pregnancy

• Published in: Theranostics Vol. 7; no. 15; pp. 3715 - 3731
• Main Authors: Cureton, Natalie, Korotkova, Iana, Baker, Bernadette, Greenwood, Susan, Wareing, Mark, Kotamraju, Venkata R, Teesalu, Tambet, Cellesi, Francesco, Tirelli, Nicola, Ruoslahti, Erkki, Aplin, John D, Harris, Lynda K
• Format: Journal Article
• Language: English
• Published: Australia Ivyspring International Publisher 01.01.2017
• Subjects: Animals; Blood Circulation - drug effects; Disease Models, Animal; Drug Carriers - administration & dosage; Drug Delivery Systems; Female; Fetal Growth Retardation - drug therapy; Humans; Injections, Intravenous; Liposomes - administration & dosage; Mice, Inbred BALB C; Mice, Inbred C57BL; Peptides - administration & dosage; Peptides - pharmacokinetics; Placenta - drug effects; Pregnancy; Research Paper; Treatment Outcome; Uterus - drug effects; Vasodilator Agents - administration & dosage; Vasodilator Agents - pharmacokinetics; Vasodilator Agents - pharmacology; drug targeting; endothelium; placenta; nitric oxide; vascular biology; pregnancy
• ISSN: 1838-7640; 1838-7640
• DOI: 10.7150/thno.19678

Fetal growth restriction (FGR) in pregnancy is commonly caused by impaired uteroplacental blood flow. Vasodilators enhance uteroplacental perfusion and fetal growth in humans and animal models; however, detrimental maternal and fetal side effects have been reported. We hypothesised that targeted uteroplacental delivery of a vasodilator would enhance drug efficacy and reduce the risks associated with drug administration in pregnancy. Phage screening identified novel peptides that selectively accumulated in the uteroplacental vasculature of pregnant mice. Following intravenous injection, the synthetic peptide CNKGLRNK selectively bound to the endothelium of the uterine spiral arteries and placental labyrinth ; CNKGLRNK-decorated liposomes also selectively bound to these regions. The nitric oxide donor 2-[[4-[(nitrooxy)methyl]benzoyl]thio]-benzoic acid methyl ester (SE175) induced significant relaxation of mouse uterine arteries and human placental arteries ; thus, SE175 was encapsulated into these targeted liposomes and administered to healthy pregnant C57BL/6J mice or endothelial nitric oxide synthase knockout (eNOS ) mice, which exhibit impaired uteroplacental blood flow and FGR. Liposomes containing SE175 (0.44mg/kg) or PBS were administered on embryonic (E) days 11.5, 13.5, 15.5 and 17.5; fetal and placental weights were recorded at term and compared to mice injected with free PBS or SE175. Targeted uteroplacental delivery of SE175 had no effect on fetal weight in C57BL/6J mice, but significantly increased fetal weight and mean spiral artery diameter, and decreased placental weight, indicative of improved placental efficiency, in eNOS mice; free SE175 had no effect on fetal weight or spiral artery diameter. Targeted, but not free SE175 also significantly reduced placental expression of 4-hydroxynonenal, cyclooxygenase-1 and cyclooxygenase-2, indicating a reduction in placental oxidative stress. These data suggest that exploiting vascular targeting peptides to selectively deliver SE175 to the uteroplacental vasculature may represent a novel treatment for FGR resulting from impaired uteroplacental perfusion.