MIT engineers have developed a way to store medical information under the skin.
Every year, a lack of vaccination leads to about 1.5 million preventable deaths, primarily in developing nations. One factor that makes vaccination campaigns in those nations more difficult is that there is little infrastructure for storing medical records, so there’s often no easy way to determine who needs a particular vaccine.
MIT researchers have now developed a novel way to record a patient’s vaccination history: storing the data in a pattern of dye, invisible to the naked eye, that is delivered under the skin at the same time as the vaccine.
In areas where paper vaccination cards are often lost or do not exist at all, and electronic databases are unheard of, this technology could enable the rapid and anonymous detection of patient vaccination history to ensure that every child is vaccinated.
The researchers showed that their new dye, which consists of nanocrystals called quantum dots, can remain for at least five years under the skin, where it emits near-infrared light that can be detected by a specially equipped smartphone.
Several years ago, the MIT team set out to devise a method for recording vaccination information in a way that doesn’t require a centralized database or other infrastructure. Many vaccines, such as the vaccine for measles, mumps, and rubella (MMR), require multiple doses spaced out at certain intervals; without accurate records, children may not receive all of the necessary doses.
In order to be protected against most pathogens, one needs multiple vaccinations.
In some areas in the developing world, it can be very challenging to do this, as there is a lack of data about who has been vaccinated and whether they need additional shots or not.
To create an “on-patient,” decentralized medical record, the researchers developed a new type of copper-based quantum dots, which emit light in the near-infrared spectrum. The dots are only about 4 nanometers in diameter, but they are encapsulated in biocompatible microparticles that form spheres about 20 microns in diameter. This encapsulation allows the dye to remain in place, under the skin, after being injected.
The researchers designed their dye to be delivered by a microneedle patch rather than a traditional syringe and needle. Such patches are now being developed to deliver vaccines for measles, rubella, and other diseases, and the researchers showed that their dye could be easily incorporated into these patches.
The microneedles used in this study are made from a mixture of dissolvable sugar and a polymer called PVA, as well as the quantum-dot dye and the vaccine. When the patch is applied to the skin, the microneedles, which are 1.5 millimeters long, partially dissolve, releasing their payload within about two minutes.
By selectively loading microparticles into microneedles, the patches deliver a pattern in the skin that is invisible to the naked eye but can be scanned with a smartphone that has the infrared filter removed. The patch can be customized to imprint different patterns that correspond to the type of vaccine delivered.
It’s possible someday that this ‘invisible’ approach could create new possibilities for data storage, biosensing, and vaccine applications that could improve how medical care is provided, particularly in the developing world.
News Source: MIT
