Oregon State researchers are moving closer to better care for life-threatening diseases of pregnancy > Oregon

PORTLAND, Oregon — Oregon State University scientists have provided a proof of concept for a new and better way of caring for women dealing with the life-threatening situation of ectopic pregnancy, which occurs when a fertilized egg implants somewhere other than the lining of the uterus .

OSU College of Pharmacy’s Olena Taratula and Oregon Health & Science University’s Leslie Myatt led a research team that used pregnant mice to develop a novel nanomedical technique to diagnose and terminate ectopic pregnancies, which are nonviable and the leading cause of maternal pregnancy death in the first trimester.

The results were published in Small journal.

The study is important because 2% of all pregnancies in the United States and between 1% and 2% worldwide are ectopic, the authors note. In the US alone, this means about 100,000 ectopic pregnancies annually.

About 98% of tubal implantations occur in the fallopian tubes, putting women at risk of bleeding and death. Complicating factors are a high incidence of misdiagnosis — ultrasound gives a wrong diagnosis 40% of the time — combined with a 10% failure rate of the primary drug, methotrexate, used to terminate an ectopic pregnancy.

About 70 women in the US die each year from ectopic pregnancies, which account for 10% of all pregnancy-related deaths. Women who survive often struggle with a range of issues arising from diagnosis and treatment, Taratula said.

“Current strategies include attempting a diagnosis with transvaginal ultrasound, treatment with methotrexate, and surgery if necessary,” she said. “The strategies are associated with a risk of tubal rupture, reduced fertility, and an increased risk of having another ectopic pregnancy — a woman who has had one ectopic pregnancy is 10% more likely to have a second.”

And even when methotrexate — a drug that terminates ectopic pregnancies by causing embryonic cells to stop dividing — is effective, it has a number of possible side effects, Taratula said: nausea, vomiting, diarrhea, elevated liver enzymes, kidney damage and lung disease .

To address the challenges associated with diagnosing and treating ectopic pregnancy, Olena Taratula and Oleh Taratula of OSU College of Pharmacy and Myatt and Maureen Baldwin of OHSU led a collaboration that developed a new type of light-sensitive nanoparticles. Nanoparticles are tiny particles of matter, as small as a billionth of a meter.

Administered intravenously, the new nanoparticles accumulate in the placenta, which nourishes and sustains the fetus via the umbilical cord. In a healthy pregnancy, the placenta forms in the uterus; in an ectopic pregnancy, it does not.

“Effective detection of the growing placenta would dramatically improve the accurate and timely identification of an ectopic pregnancy,” said Olena Taratula.

Once the nanoparticles are concentrated in the placenta, the organ can be seen through fluorescent and photoacoustic imaging, and it quickly becomes clear whether the placenta is where it is supposed to be. If this is the case, the patient would know that she did not have an ectopic pregnancy and the embryo would not be affected by the particles as they do not cross the placenta.

If the placenta is in a fallopian tube or other incorrect location, exposure to near-infrared light could terminate the pregnancy, raising the temperature of the nanoparticles to over 43 degrees Celsius and causing heat to irreparably disrupt placental function.

“Our main goal in this study was to evaluate our nanoparticle’s ability to identify and visualize the developing placenta and demonstrate its photothermal capabilities,” Taratula said. “Our experimental results are promising and the next step is to validate them in other animal models to further advance the application of this technology.”

Oregon State’s Abraham Moses, Leena Kadam, Anna St. Lorenz, Terry Morgan, Jessica Hebert, Youngrong Park, Hyelim Lee, Ananiya Demessie, Tetiana Korzun, Babak Mamnoon, and Adam Alani also participated in the College of Pharmacy, das research OHSU Department of Obstetrics and Gynecology, the National Institutes of Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

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