German researchers claim to have developed “cyborg sperm” as a means to countering infertility, a solution that they say could be superior to current methods of in vitro fertilization. Specifically, they used “miniaturized vehicles” to guide cow sperm in order to fertilize cow eggs in the lab.
“The operation of miniaturized vehicles that perform tasks and interact with living cells inside the human body appears to be one more 20th century dream that today’s engineers finally become ready to tackle,” the researchers wrote in their study, published in the journal “Nano Letters.”
“In recent years, numerous approaches have emerged from various laboratories to employ such micromotors that can be powered and controlled on a scale that allows them to assist or interfere with cellular processes,” they added.
Applying that approach, the researchers attached an artificial propulsion system to samples, which were extracted from bovine sperm, to assist with their movement.
“We present artificially motorized sperm cells — a novel type of hybrid micromotor, where customized microhelices serve as motors for transporting sperm cells with motion deficiencies to help them carry out their natural function,” they said.
Researchers were able to fertilize the eggs with a 40-50 percent success rate under otherwise optimal conditions, with “limitations in reliability and reproducibility” standing as the remaining challenges.
“In our setup, we have to transfer sperms and [female eggs] from proper culture dishes to the fluidic platform causing unwanted time delays and temperature fluctuations,” they said. “Current statistical limitations arising from the complex individual capture of single sperm cells require extensive and focused experimental work to increase the probability to achieve successful fertilization.
“Still, this work serves to demonstrate a new approach to artificial reproduction that is, in principle, also applicable in vivo and would thus allow to avoid all complications” of in vitro, which involves extracting eggs before reimplantation. That method has a general success rate of 20 to 40 percent and costs up to $10,000, substantially more than the in vivo approach would cost.
In order to complete their system, the researchers suggested they will need to perfect the navigational components and reduce complications from immune system response.
“There is … much exciting work to be done starting from the first steps reported here,” the team said. “It remains to stress that, ultimately, the strength of this novel fertilization approach lies in its potential in vivo applicability.”
