Microcapsules explode onto the scene

None one really likes having injections – but would you opt to have exploding capsules inserted which deliver the medicine instead? That is the hope of a group of Belgian chemists who have developed “self-exploding” microcapsules.

They say that the microcapsules could one day precisely release drugs and vaccines inside the human body - weeks or even months after injection - and change how some vaccines are administered.
Booming boosters. Could vaccination
boosters one day be delivered
by exploding capsule?

Unlike some other microcapsules, which release their drug cargo only when exposed to ultrasonic waves or another external trigger, the new system relies on internal mechanisms to do the same job. Each of the new microparticles features a biodegradable gel core that is surrounded by a lipid membrane. As the gel biodegrades, pressure builds up in the membrane. Eventually the microcapsule ruptures, releasing the medication.

One of the main challenges in developing the capsules was to ensure that they didn’t explode too early. Bruno De Geest of the department of Pharmaceutics at Ghent University and member of the research team, told Laboratory News: “The potential hazards of early explosion should be quite low due to the fact that the microgel core gives some mechanical strength to the microcapsules and the degradation rate of the microgel core is pH and temperature dependent.”

The system could change how some vaccines are administered. Instead of an initial injection followed by a series of boosters, for instance, certain vaccines could be given in a single shot with the “booster” microcapsules timed to rupture at appropriate intervals.

The research appeared in the print issue of the American Chemical Society’s journal Biomacromolecules.