Placenta-Targeted Therapy May Reduce Premature Births, Pregnancy Complications

Delivering growth hormone to the placenta found to increase fetus growth in mouse model.

Researchers in a recent study were able to offer additional support to the placenta, which could possibly prevent premature births and treat complications that effect over 10% of pregnant women.

"Our findings emphasize the similarities between placentas and tumors," said co-author Erkki Ruoslahti, MD, PhD. "That similarity makes it possible to take some of the existing tumor-homing peptides and make use of them in targeting drugs to the placenta. This paper shows that it is possible to increase the delivery of drugs into the placenta via these peptides."

According to the study published by Science Advances, there are no drugs that can treat pregnancy complications resulting from the placenta growing or functioning improperly. As a result, sometimes doctors have to induce early labor, which can increase the risk of infection and cerebral palsy in the infant and potentially increase the risk of heart disease and diabetes later in life.

Researchers in the current study found that 2 peptides used to selectively target tumors can perform the same on a placenta and deliver drugs to improve organ function and benefit the fetus without any harm.

"Placentas behave like well-controlled tumors," said lead author Lynda Harris, MD. "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. 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."

Researchers used a mouse model to deliver a growth hormone to the placenta via peptide-coated nanoparticles, according to the study. The drug caused underdeveloped fetuses to grow, but did not affect normal-sized fetuses. Also, the drug did not build-up in the mother’s organs and was not detected in the fetuses.

Researchers believe this treatment could be used in humans eventually, however, a potentially harmful effect may exist for mothers with undiagnosed cancer since the drug could also target their tumors, but a screening program could be implemented to prevent this.

"Only one drug for use during pregnancy has been licensed in the last 20 years," concluded Dr Harris. "By developing this 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."