doi:10.1038/nindia.2018.60 Published online 15 May 2018
Researchers have synthesised magnetic nanomotors that can cruise inside cells, making them potentially useful for intracellular sensing and drug delivery1.
External stimuli such as electric fields, ultrasound and chemicals have been experimentally used to push artificial nanomaterials in different media such as blood and saliva. These methods cannot efficiently control the motion of the nanomaterials in biological systems. For instance, ultrasound damages cells by generating stress on them.
In search of a safe method, scientists from the Indian Institute of Science in Bangalore, India, led by Ambarish Ghosh, produced the magnetic nanomotors by using silicon dioxide and a thin film of iron. They then tested the nanomotors’ efficiency to enter and move inside cells in response to rotating magnetic fields.
When incubated with cervical cancer cells and specific animal cells, the nanomotors easily entered the cells and moved within the cells’ cytoplasm in response to the magnetic fields. Even after an hour of incubation, the cells survived, suggesting that the nanomotors are non-toxic.
The nanomotors could move forward inside the cells. When they bumped into an intracellular obstacle, they came backward and resumed their forward journey on a slightly deviated path. Since the intracellular space equals the width of nanomotors, they could travel all around inside the cells, adopting such motion.
Besides intracellular sensing and delivery, the nanomotors are potentially useful for undertaking fundamental studies in cell biology and biophysics, says co-researcher Malay Paul.
1. Pal, M. et al. Maneuverability of magnetic nanomotors inside living cells. Adv. Mater. (2018) doi:10.1002/adma.201800429