Many pregnancy complications occur due to a malfunctioning placenta that fails to deliver the right amount of nutrients to a growing fetus or fails to maintain a consistent healthy environment in which the fetus can grow. But an international research team has come up with a way to deliver drugs directly to the placenta in order to boost its function.
Nearly 10% of pregnancies have some type of complication that may lead to premature birth or pre-eclampsia, a condition that causes high blood pressure and retention of fluids that effects the growth of the fetus.
Researchers realized that the way cancer is treated was providing a clue. Much cancer research focuses on delivering drugs to kill tumors without affecting the rest of the body. This selective targeting had potential for working on the placenta.
According to lead researcher Lynda Harris from the UK’s University of Manchester, placentas act like well-controlled tumors. She explains that they “grow quickly, produce growth hormones, and evade the immune system.”
Because of that behavior, scientists surmised that they could selectively target the placenta to deliver drugs to improve its function and thus directly treat some pregnancy complications.
Harris and her team wanted to see how the placenta would respond to two tumor-targeting peptides – called CGKRK and IRGD – which are chains of amino acids that can be fashioned into miniature drug-carrying capsules. When they experimented on mice, they were able to deliver a growth hormone to the placenta that improved its function. Better still, when these same peptides were tested on human placental tissue, they penetrated the membrane and were bound to the cells.
Further human trials are needed, but the outlook is hopeful. The main concern is that mothers who get this treatment must be carefully and fully screened first for undiagnosed cancers, since the peptides would otherwise not know what to target – the placenta, or an undiscovered tumor.
There are currently no medications available to treat a poorly functioning placenta. If a baby is not growing as it should, the only option is inducing delivery and the risks associated with premature birth are significant.
The new research shows that growth hormone delivered directly to the placenta helped grow abnormally small fetuses, and no traces of the drug were found in either the woman or her organs after they had time to do their work.
While additional research is needed, Harris says that by delivering this platform there are now “more possibilities for new drugs that could be adapted and safely used to treat common but serious pregnancy complications.”
