• Posted December 13, 2024

In Mouse Studies, New Hope Against a Dangerous Complication of Pregnancy

The same technology behind COVID vaccines might be able to protect both the mother and child from a dangerous complication of pregnancy.

A new mouse study published Dec. 11 in the journal Nature shows that injections based on that vaccine platform reduced the risk of preeclampsia in lab mice.

Preeclampsia is persistent high blood pressure that occurs during pregnancy or after giving birth. It can threaten the life of both the mother and baby, or leave the mom with severe organ damage.

The experimental injection “was able to deliver an mRNA therapeutic that reduced maternal blood pressure through the end of gestation and improved fetal health and blood circulation in the placenta,” said researcher Kelsey Swingle, a doctoral student in bioengineering at the University of Pennsylvania School of Engineering and Applied Science. “Additionally, at birth we saw an increase in litter weight of the pups, which indicates a healthy mom and healthy babies."

Preeclampsia affects 3% to 5% of pregnancies, researchers said in background notes. There’s no cure for the condition; instead, women take blood pressure medication or stay on bed rest.

Preeclampsia arises due to insufficient blood flow to the placenta, which causes a mom’s blood pressure to rise while restricting blood flow to the fetus.

Researchers figured that a drug designed to get into the placenta despite the restricted blood flow might help resolve the condition.

To design that drug, researchers turned to the particles used to deliver mRNA COVID vaccines.

The mRNA that creates an immune response to COVID is delivered inside lipid nanoparticles (LNP), which are microscopic balls of fatty material. These particles dissolve inside the human body, releasing the payload they’re carrying.

Swingle examined 98 different lipid nanoparticles, assessing their ability to reach the placenta of pregnant mice.

Swingle finally landed on a particle that provided 100-fold better mRNA delivery to the placenta than an FDA-approved lipid nanoparticle.

The results showed that the one-time injection cured mice with preeclampsia until the end of their pregnancy.

“At this stage in our research, we would bring this LNP to larger animals such as rats and guinea pigs first, to determine how well it works in the ‘gold standard’ models of preeclampsia before we could advance this work to human trials,” Swingle said in a university news release.

“Testing our LNP on guinea pigs will be particularly interesting, as their placenta closely resembles a human’s and their gestational period is longer, up to 72 days,” Swingle added. “We will be asking the questions ‘How many doses do these animals need?’ ‘Will the minimum effective dose change?’ and ‘How well does our current LNP work in each?’”

This research also shows the potential for using lipid nanoparticles to deliver cures for other diseases and disorders, Swingle concluded.

More information

Johns Hopkins Medicine has more about preeclampsia.

SOURCE: University of Pennsylvania, news release, Dec. 11, 2024