Targeted Drug-Delivery In Pregnancy Complications

Targeted Drug-Delivery System May Treat Pregnancy Complications

 A treatment approach that typically targets tumors may also safely deliver medications directly to a pregnant woman's placenta, a new mouse study suggests.
This type of treatment might one day help reduce pregnancy complications, such as preeclampsia, the researchers said. And it could also help prevent premature deliveries without harming fetuses, they added.

"Placentas behave like well-controlled tumors," study author Lynda Harris, of the University of Manchester in England, explained in a news release from Sanford Burnham Prebys Medical Discovery Institute in California. "They grow quickly, produce growth hormones and evade the immune system."

"A lot of cancer research focuses on finding ways of delivering drugs to kill the tumor without affecting the rest of the body," Harris added. "We had the idea that if we could selectively target the placenta in the same way, we could deliver other drugs to help improve placental function and therefore treat pregnancy complications."

Roughly 10 percent of babies are born prematurely, the March of Dimes reports, and a poorly functioning placenta is an underlying cause of many problems during pregnancy.
Without drugs to treat these issues, doctors are often forced to deliver babies early, the researchers explained.

Working with mice, the international team of scientists found that two chains of amino acids that are used to target tumors can also safely target placentas, delivering medication to support a growing mouse fetus. Amino acids are the building blocks of proteins.

In the study, the researchers delivered a growth hormone to mice placenta through tiny amino acid-coated nanoparticles. The drug did not affect normal-sized fetuses, but it prompted those that were too small to grow.

At the same time, the drug did not accumulate inside either pregnant mice or developing mouse fetuses.

Directing medication to the placenta might also help treat complications during pregnancy and avoid some premature deliveries, according to authors of the study published May 6 in the journal Science Advances.

The researchers said their findings suggest this treatment approach could one day be used on humans, although animal research often does not pan out in people.

They noted the treatment might not be appropriate for women with undiagnosed cancers because these drugs could also target tumors. But cancer screening could get around this potential issue, they added.

"Only one drug for use during pregnancy has been licensed in the last 20 years," Harris said. "By developing this [drug delivery] platform, we have opened up the possibility that any number of new drugs can be adapted and then used safely to treat common and serious pregnancy complications."


More information
The American Pregnancy Association provides more information on the placenta.