Microscopic crystals could soon be zipping drugs around your body, taking them to diseased organs. In the past, this was thought to be impossible because the crystals, which have special magnetic properties, were so small that scientists could not control their movement. But now a team of Chinese researchers has found the solution, and their discovery has opened new applications that could use these crystals to improve-and perhaps even save-many lives.
Kezheng Chen and Ji Ma from Quingdou University of Science and Technology, Quingdou, China, have published a method of producing superparamagnetic crystals that are much larger than any that have been made before. They recently published their findings in Physics Letters A.
If some magnetic materials, such as iron oxides, are small enough-perhaps a few millionths of a millimeter across, smaller than most viruses-their magnetization randomly flips as the temperature changes. By applying a magnetic field to these crystals, scientists can make them almost as strongly magnetic as ordinary fridge magnets. This is the strongest type of magnetism known. This phenomenon is called superparamagnetism.
In theory, superparamagnetic particles could be ideal for drug delivery, as they can be directed to a tumor simply by using a magnetic field. Their tiny size, however, has made them difficult to guide precisely-until now.
“The largest superparamagnetic materials that we have been able to make before now were clusters of nanocrystals that were together about a thousand times smaller than these,” commented Chen. “These larger crystals are easier to control using external magnetic fields, and they will not aggregate when those fields are removed, which will make them much more useful in practical applications, including drug delivery.”
This article was adapted from information provided by Elsevier.
