December 15, 2013
Sperm Driven Micro-Robot Could Aid In IVF And Drug Delivery
Brett Smith for redOrbit.com - Your Universe Online
New Scientist reports that the system involves placing a bull sperm inside a nanotube. The scientists are then able to remotely control the movements of the sperm using magnetic fields. The speed of the sperm can be controlled be changing the temperature of its environment, according to the report.
"The combination of a biological power source and a microdevice is a compelling approach to the development of new microrobotic devices with fascinating future application," the German scientists wrote in their paper.
To create the biological-mechanical hybrid, the researchers from the Institute for Integrative Nanosciences in Dresden, Germany fashioned tiny iron and titanium tubes 50 microns long and 5 to 8 microns in diameter. Next, the researchers added the tubes to a fluid with thawed bull sperm. The tubes were made with one end slightly smaller than the other, allowing a sperm to swim into one end and become trapped with their flagella still able to move. Using magnetic fields, the team could then control the trapped sperm in much the same way a compass needle aligns with Earth's magnetic field.
Team member Oliver Schmidt told the New Scientist that sperm cells are an ideal delivery system because they are harmless to the human body, don’t need an external power source and can pass through viscous liquids.
The novel system could be used to improve the efficiency of in-vitro fertilization techniques and reduce the number of unintended multiple births that these techniques cause. According to a report published in the American Journal of Obstetrics & Gynecology last month, pregnancies that end in the delivery of twins cost about five-fold more than singleton pregnancies, and the delivery of triplets or more cost nearly 20 times as much as singletons.
In that study, researchers used data from the Truven Health MarketScan Commercial Claims and Encounters Database to examine the differences in costs among the different types of pregnancies. The researchers’ study cohort included all women between the ages of 19 and 45 years old who delivered at least one live infant between January 2005 and September 2010 – equaling nearly 440,000 delivery events. Of these, about 97 percent were singletons, about 2.8 percent were twins and 0.13 percent of the pregnancies produced triplets or more.
The research team included medical costs incurred by mothers during the 27 weeks leading up to and about 30 days after the delivery date. They also considered medical costs for infants up until their first birthday.
"By taking a broad approach, we have shown that medical expenses attributable to mothers and infants varied according to birth multiplicity," said study author Dongmu Zhang, a research leader at Merck & Co. "For singleton pregnancy, maternal expenses accounted for about 60 percent of overall cost; whereas for twins or higher-order multiple births, expenses for infant care accounted for about 70 percent and 85 percent of total expenses, respectively."